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1. 2 1 2 3 4 ADPSIZE ADPASS IREFLG ADPENE 5 6 7 8 IRI ENEREREN foo VARIABLE DESCRIPTION ADPFREQ Time interval between adaptive refinements see Figure 7 1 ADPTOL Adaptive error tolerance in degrees for ADPOPT set to 1 or 2 below If ADPOPT is set to 8 ADPTOL is the characteristic element size ADPOPT Adaptive options EQ 1 angle change in degrees per adaptive refinement relative to the surrounding elements for each element to be refined 7 6 CONTROL LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION EQ 2 total angle change in degrees relative to the surrounding element for each element to be refined For example if the adptol 5 degrees the element will be refined to the second level when the total angle change reaches 5 degrees When the angle change is 10 degrees the element will be refined to the third level EQ 7 3D r adaptive remeshing for solid elements Solid element type 13 a tetrahedron is used in the adaptive remeshing process A completely new mesh is generated which is initialized from the old mesh using a least squares approximation The mesh size is currently based on the minimum and maximum edge lengths defined on the CONTROL_REMESHING keyword input This option remains under development and we are not sure of its reliability on complex geometries EQ 8 2D r adaptive remeshing for axisymmetric and plane strain solid
2. VARIABLE DESCRIPTION BOXID Box ID Define unique numbers XMN Minimum x coordinate XMX Maximum x coordinate YMN Minimum y coordinate YMX Maximum y coordinate ZMN Minimum z coordinate ZMX Maximum z coordinate 10 2 DEFINE LS DYNA Version 960 DEFINE DEFINE BOX ADAPTIVE Purpose Define a box shaped volume enclosing the elements where the adaptive level is to be specified If the midpoint of the element falls within the box the adaptive level is reset Elements falling outside of this volume use the value MAXLVL on the CONTROL ADAPTIVE control cards Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 VARIABLE DESCRIPTION BOXID Box ID Define unique numbers XMN Minimum x coordinate XMX Maximum x coordinate YMN Minimum y coordinate YMX Maximum y coordinate ZMN Minimum z coordinate ZMX Maximum z coordinate LS DYNA Version 960 10 3 DEFINE DEFINE VARIABLE DESCRIPTION PID Part ID If zero all active element within box are considered LEVEL Maximum number of refinement levels for elements that are contained in the box Values of 1 2 3 4 allow a maximum of 1 4 16 64 elements respectively to be created for each original element 10 4 DEFINE LS DYNA Version 960 DEFINE DEFINE BOX COARSEN Purpose Define a specific box shaped volume indicating elements which are protected from mesh coarsening See
3. EHEN EHEN EIER EEE VARIABLE DESCRIPTION SBSRID Slipring ID A unique number has to be used SBIDI Seat belt element 1 ID SBID2 Seat belt element 2 ID FC Coulomb friction coefficient SBRNID Slip ring node NID Remarks Elements 1 and 2 should share a node which is coincident with the slip ring node The slip ring node should not be on any belt elements Sliprings allow continuous sliding of a belt through a sharp change of angle Two elements 1 amp 2 in Figure 12 4 meet at the slipring Node B in the belt material remains attached to the slipring node but belt material in the form of unstretched length is passed from element 1 to element 2 to achieve slip The amount of slip at each timestep is calculated from the ratio of forces in elements 1 and 2 The ratio of forces is determined by the relative angle between elements 1 and 2 and the coefficient of friction u The tension in the belts are taken as and T2 where T is on the high tension side and T is the force on the low tension side Thus if T is sufficiently close to no slip occurs otherwise slip is just sufficient to reduce the ratio to No slip occurs if both elements are slack The out of balance force at node B is reacted on the slipring node the motion of node B follows that of slipring node 12 28 ELEMENT LS DYNA Version 960 ELEMENT If due to slip through the slipring the unstretched length of
4. Ee ran E EREDE eue 7 43 CONTROL IMPLICIT 5 7 45 CONTROL IMPLICIT 7 47 CONTROL IMPLICIT GENERAL 42 sense 7 49 CONTROL IMPLICIT SOLUTION 2 22 22 let ex aus rues 7 51 CONTROL IMPLICIT 5 222222 E 7 55 CONTROL IMPLICIT STABILIZATION 7 58 CONTROL NONLOCAE bee sense s he 1 59 CONTROL OUTPUT 2 2 2222222 Ion 7 60 CONTROL PARALLEL itte an a RR one eee edidere ue 7 62 CONTROEHREMESHING itio cto epo Eee Un a eo er et REFUS SANE ERR des eH n eer Hae erbe dde 7 64 CONEROL RIGID is scart sons rte E ee Ra In kg 7 65 CONTROL SHEL DIM ipii 7 67 CGONTROL SOLID aoi 7 11 CONTROE SOLUTION eie u ee nalen E 1 12 CONTROL SPE Hier Pi em Mase eens 7 73 CONTROL STRUCTURED HH m emm 7 74 CONTROL SUBCY CLE un ee nee BEE HD 7 75 CONTROL TERMINATION 2s ettet dee pees rue s HERR eo 7 76 CONTROL THERMAL NONLINEFAR 2 2222 en nassen 7 77 CONTROL THERMAL SOLVER e ete o pe Uie cet 7 78 CONTROL THERMAL 5 7 80 CONTROL ZTIMESTER e 7 81 DAMPING iere XXe anna Bin QU
5. RR KERNE EE EET LR ERR ren 10 11 DEEINE CURVE FBEDBAGCK onn ge la II 10 13 DEFINE CURVE SMOOTH cdi terrere essen 10 16 DERINE CURVE TRIM nee ae ot Pee ee dad es eg ere abe 10 18 DBEEINE SD ORIENTATION 5 ek re to Lohr e RESP e re See ii pra iue 10 21 DEHINE TABEE 22 10 23 DEFINE _TRANSFORMATION s ueenen 10 25 DEEINE VECTOR eve sends Pet Father vo td cece Pepe e e ERO Yee erbe 10 29 DEFORMABLE 11 1 DEFORMABLE TO RIGID ertt 2er sehen 11 2 DEFORMABLE RIGID AUTOMATIC 11 3 DEFORMABLE TO RIGID 11 7 5 84 hr AE LEE RI En 12 1 SEULEMENT BEAM OPTION ass et oerte ote e de rt el en sense 12 2 ELEMENT DIRECT MATRIX 12 8 ELEMENT DISCRETE RR Ba ede e ev ERE Et nn 12 10 essen oto Rb eunte uten iin 12 11 EEEMENT MASS Hu are PRA e e Fo doge ep e ede eo Uo e e Py doge de e rev bance 12 13 LS DYNA Version 960 TABLE OF CONTENTS ELEMENT SEATBELT u 2 10 I EP RE Rai 12 14 ELEMENT SEATBELT 12 15 ELEMENT_SEATBELT_PRETENSIONER
6. 12 16 ELEMENT SEATBELT 12 18 ELEMENT_SEATBELT SENSOR trei ERR bep S ass 12 24 EEEMENT SEATBEET SSEIPRING Sa oes mette Eee RERO RE a 12 28 ELEMENT SHELL OPTION vessen eie reet teet pee teh erede the 12 30 EEEMENT SOLID A OPTION a each 12 34 eia e D US Eee ER E EO E Pee Rete E 12 39 ELEMENT _TRIM 8242222222 re D ee V ee odd atia ee edes 12 40 EBDEMENT TSHELLE 5 bet ae BER 12 41 6 vcre esu voe rx e ERRARE E V HES MEN OS V Vn E Vr V Pr s So s eu Oa 13 1 32554404 escenas escasas ERARETO 13 2 EOS JWL siegen ana iR 13 4 EOS SACK TUESDAY Er AH eaae 13 5 EOS GRUNEISEN isn a 13 6 EOS RATIO OFZPOLYNOMIALS using 13 8 EOS LINEAR POLYNOMIAL WITH ENERGY 13 12 EOS IGNITION AND GROWTH OF REACTION IN HE A 13 14 EOS TABULATED 13 18 EOS TABULATED s t tese es an san Base eek 13 20 5 13 22 8 3 2 eeepc 13 27 EOS JWL Barone ans ke Hesse 13 30 HOURG LASS cas N DER El EPOR TEE E V E 14
7. COMPONENT HYBRIDIII JOINT OPTION LS DYNA Version 960 4 COMPONENT COMPONENT COMPONENT_GEBOD_OPTION Purpose Generate a rigid body dummy based on dimensions and mass properties from the GEBOD database The motion of the dummy is governed by equations integrated within LS DYNA separately from the finite element model Default joint characteristics stiffnesses stop angles etc are set internally and should give reasonable results however they may be altered using the COMPONENT_GEBOD_JOINT command Contact between the segments of the dummy and the finite element model is defined using the CONTACT_GEBOD command The use of a positoning file is essential with this feature see Appendix K for further details OPTION specifies the human subject type The male and female type represent adults while the child is genderless MALE FEMALE CHILD Card Format Card 1 of 2 1 2 3 4 5 6 7 8 u d id s a a a mE VARIABLE DESCRIPTION DID Dummy ID A unique number must be specified UNITS System of units used in the finite element model EQ 1 Ibf sec2 in inch sec EQ 2 kg meter sec EQ 3 kgf sec2 mm mm sec EQ 4 metric ton mm sec EQ 5 kg mm msec SIZE Size of the dummy This represents a combined height and weight percentile ranging from 0 to 100 for the male and female types For the child the number of months of age is input with an admissible range from 24 to 240 4 2 COMPONENT LS DY
8. VARIABLE DESCRIPTION XC x coordinate of center of mass If nodal point NODEID is defined XC YC and ZC are ignored and the coordinates of the nodal point NODEID are taken as the center of mass YC y coordinate of center of mass ZC z coordinate of center of mass TM Translational mass LS DYNA Version 960 5 51 CONSTRAINED CONSTRAINED VARIABLE DESCRIPTION IRCS Flag for inertia tensor reference coordinate system EQ 0 global inertia tensor EQ 1 principal moments of inertias with orientation vectors as given below NODEID Optional nodal point defining the CG of the rigid body If this node is not a member of the set NSID above its motion will not be updated to correspond with the nodal rigid body after the calculation begins PNODE and NODEID can be identical if and only if PNODE physically lies at the mass center at time zero Card 3 of 4 Required for the INERTIA option Card 3 1 2 3 4 5 6 7 8 vine fone fw fine om me fete fe EEE BEE EN VARIABLE DESCRIPTION IXX Ixx xx component of inertia tensor IXY Ixy set to zero if IRCS 1 IXZ Ixz set to zero if IRCS 1 IYY yy component of inertia tensor IYZ Iyz set to zero if IRCS 1 IZZ Izz zz component of inertia tensor Card 4 of 4 Required for the INERTIA option Card 4 1 2 3 4 5 6 7 8 w fefefe f 5 52 CONSTRAINED LS DYNA Version 960 CONSTRAINED VARIABLE DESCRIPTION VTX x rigid body initial trans
9. FS Static coefficient of friction if FS is gt 0 and not equal to 2 The frictional coefficient is assumed to be dependent on the relative velocity of the surfaces in contact u FD FS FD e The two other possibilities are DC v e EQ 1 If the frictional coefficients defined in the PART section are to be used set FS to a negative number 1 0 WARNING Please note that the FS 1 0 option applies only to contact types SINGLE SURFACE AUTOMATIC GENERAL AUTOMATIC _ SINGLE SURFACE AUTOMATIC NODES TO SURFACE AUTO MATIC SURFACE TO SURFACE AUTOMATIC ONE WAY SUR FACE TO SURFACE and ERODING SINGLE SURFACE EQ 2 For contact types SURFACE TO SURFACE and ONE WAY SURFACE TO SURFACE the dynamic coefficient of friction points to the table see DEFINE TABLE The table ID is give by FD below giving the coefficient of friction as a function of the relative velocity and pressure This option must be used in combination with the thickness offset option See Figure 6 1 FD Dynamic coefficient of friction The frictional coefficient is assumed to be dependent on the relative velocity vye of the surfaces in contact u FD FS Give table ID if FS 2 Note For the special contact option TIED SURFACE TO SURFACE FAILURE only the variables FS and FD act as failure stresses i e LS DYNA Version 960 6 9 CONTACT CONTACT VARIABLE FS FD DC VDC PENCHK BT DT 6 10 CONTACT
10. 1 Nodes connected by a spot weld cannot be members of another constraint set that constrain the same degrees of freedom a tied interface or a rigid body i e nodes cannot be subjected to multiple independent and possibly conflicting constraints Also care must be taken to ensure that single point constraints applied to nodes in a constraint set do not conflict with the constraint sets constrained degrees of freedom LS DYNA Version 960 5 69 CONSTRAINED CONSTRAINED 2 Failure of the spot welds occurs when 5 5 where fn and f are the normal and shear interface force Component fn is nonzero for tensile values only 3 When the failure time TF is reached the spot weld becomes inactive and the constrained nodes may move freely 4 Spot weld failure due to plastic straining occurs when the effective nodal plastic strain exceeds the input value 7 This option can model the tearing out of a spotweld from the sheet metal since the plasticity is in the material that surrounds the spotweld not the spotweld itself A least squares algorithm is used to generate the nodal values of plastic strains at the nodes from the element integration point values The plastic strain is integrated through the element and the average value is projected to the nodes via a least square fit This option should only be used for the material models related to metallic plasticity and can result is slightly increased run ti
11. BOUNDARY Define the nodes k 1 k 2 k n while moving counterclockwise around the boundary Figure 3 7 When defining a transmitting boundary in 2D define the node numbers in the node set in consecutive order while moving counterclockwise around the boundary 3 26 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY OUTFLOW CFD OPTION Available options include SEGMENT SET Purpose Define passive outflow boundary conditions for the incompressible flow solvers These et conditions are active only when SOLN 4 or SOLN 5 on the CONTROL_SOLUTION For the SET option define the following card Card Format Card 1 1 2 3 4 5 6 7 8 For the SEGMENT option define the following card Card Format Card 1 1 2 3 4 5 6 7 8 mE i UT polo VARIABLE DESCRIPTION SSID Segment set ID N2 Node ID s defining segment LS DYNA Version 960 3 27 BOUNDARY BOUNDARY Remarks In the incompressible flow solver the role of the outflow boundary conditions is to provide a computational boundary that is passive particularly in the presence of strong vortical flow structures Typically this boundary condition is applied at boundaries that have been artificially imposed to emulate far field conditions in a large physical domain 3 28 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY PRESCRIBED CFD OPTION Available options include NODE SET Purpose Define an imposed nodal vari
12. DC Exponential decay coefficient The functional coefficient is assumed to be dependent on the relative velocity vreg of the surfaces in contact FD FS P Coefficient for viscous friction This is necessary to limit the friction force to a maximum A limiting force is computed VC A Acont being cont the area of the segment contacted by the node in contact The suggested o 48 value for VC is to use the yield stress in shear VC where o is the yield stress of the contacted material 21 8 PART LS DYNA Version 960 PART VARIABLE DESCRIPTION OPTT Optional contact thickness This applies to shells only SFT Optional thickness scale factor for PART ID in automatic contact scales true thickness This option applies only to contact with shell elements True thickness is the element thickness of the shell elements SSF Scale factor on default slave penalty stiffness for this PART ID whenever it appears in the contact definition If zero SSF is taken as unity PRBF Print flag for RBDOUT and MATSUM files EQ 0 default is taken from the keyword CONTROL_OUTPUT EQ 1 write data into RBDOUT file only EQ 2 write data into MATSUM file only EQ 3 do not write data into RBDOUT and MATSUM ANSID Attachment node set ID This option should be used very cautiously and applies only to rigid bodies The attachment point nodes are updated each cycle whereas other nodes in the rigid body ar
13. However it should be noted that the drill projection can result in a loss of invariance to rigid body motion when the elements are highly warped For LS DYNA Version 960 7 69 CONTROL CONTROL moderately warped configurations the drill projection appears quite accurate In crashworthiness and impact analysis elements that have little or no warpage in the reference configuration can become highly warped in the deformed configuration and may affect rigid body rotations if the drill projection is used Of course it is difficult to define what is meant by moderately warped The full projection circumvents these problems but at a significant cost The cost increase of the drill projection versus no projection as reported by Belytschko and Leviathan is 12 percent and by timings in LS DYNA 7 percent but for the full projection they report a 110 percent increase and in LS DYNA an increase closer to 50 percent is observed In Version 940 xx of LS DYNA the drill projection was used exclusively but in one problem the lack of invariance was observed and reported consequently the drill projection was replaced in the Belytschko Leviathan shell with the full projection and the full projection is now optional for the warping stiffness in the Belytschko Tsay and Belytschko Wong Chiang elements Until this problem occurred the drill projection seemed okay In verion 950 xx and later versions of LS DYNA the Belytschko Leviathan shell is somewhat sl
14. Purpose This contact option provides of means of modeling parts which are shrink fitted together and are therefore prestressed in the initial configuration This option turns off the nodal interpenetration checks which changes the geometry by moving the nodes to eliminate the interpenetration at the start of the simulation and allows the contact forces to develop to remove the interpenetrations The load curves defined in this section scale the interface stiffness constants such that the stiffness can increase slowly from zero to a final value with effect that the interface forces also increase gradually to remove the overlaps Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCIDI Load curve ID which scales the interface stiffness during dynamic relaxation This curve must originate at 0 0 at 0 and gradually increase LCID2 Load curve ID which scales the interface stiffness during the transient calculation This curve is generally has a constant value of unity for the duration of the calculation if LCID1 is defined If LCID1 0 this curve must originate at 0 0 at time 0 and gradually increase to a constant value Remarks Extreme caution must be used with this option First shell thickness offsets are taken into account for deformable shell elements Furthermore SEGMENT ORIENTATION FOR SHELL ELEMENTS AND INTERPENETRATION CHECKS ARE SKIPPED Therefore it is necessary in the problem setup to ensure that all contact segm
15. Card 5 1 2 3 4 5 6 7 8 Type Optional card required for IRCS 1 Define two local vectors or a local coordinate system ID Card 6 1 2 3 4 5 6 7 8 _ pe fe foe foe foe fa fe fe fom 21 4 PART LS DYNA Version 960 PART An additional Card is required for the REPOSITION option Optional Additional Card is required for the CONTACT option WARNING IFS FD DC and VC are specified they will not be used unless FS is set to a negative value 1 0 in the CONTACT section These frictional coefficients apply only to contact types SINGLE_SURFACE AUTOMATIC_ GENERAL AUTOMATIC SINGLE SURFACE AUTOMATIC NODES TO AUTOMATIC SURFACE AUTOMATIC ONE WAY and ERODING SIN GLE SURFACE Default values are input via CONTROL CONTACT input Optional An additional Card is required for the PRINT option This option applies to rigid bodies and provides a way to turn off ASCII output in files RBDOUT and MATSUM Optional LS DYNA Version 960 21 5 PART PART An additional Card is required for the ATTACHMENT_NODES option All nodes are treated as attachment nodes if this option is not used Attachment nodes apply to rigid bodies only The motion of these nodes which must belong to the rigid body are updated each cycle Other nodes in the rigid body are updated only for output purposes Include all nodes in the attachment node set which interact with the structure through joints
16. INTERPOLATION card is required for each constraint definition The input list of independent nodes is terminated when the next card is found Card Format 1 2 3 4 5 6 7 8 LITT LL II Cards 2 3 4 etc Define one card per independent node Input is terminated when a card is found 1 2 3 4 5 6 7 8 vewe nm ror TWGHTX TWGHTY TWGHTZ RWGHTX RWGHTY RWGHTZ fo 123456 TWGHTX TWGHTX TWGHTX TWGHTX TWGHTX VARIABLE DESCRIPTION ICID Interpolation constraint ID DNID Dependent node ID This node should not be a member of a rigid body or elsewhere constrained in the input DDOF Dependent degrees of freedom The list of dependent degrees of freedom consists of a number with up to six digits with each digit representing a degree of freedom For example the value 1356 indicates that degrees of freedom 1 3 5 and 6 are controlled by the constraint The default is 123456 Digit degree of freedom ID s 5 20 CONSTRAINED LS DYNA Version 960 CONSTRAINED VARIABLE DESCRIPTION EQ 1 x 2 EQ 3 z EQ 4 rotation about x axis EQ 5 rotation about y axis EQ 6 rotation about z axis INID Independent node ID IDOF Independent degrees of freedom using the same form as for the dependent degrees of freedom DDOF above TWGHTX Weighting factor for node INID with active degrees of freedom IDOF This weight scales the x translational component It is normally sufficien
17. Nodal point end 2 This node is optional for the spot weld beam type 9 since if it not defined it will be created automatically and given a nonconfliciting nodal point ID Nodes N1 and N2 are automatically positioned for the spot weld beam element Nodal point 3 The third node N3 is optional for beam types 3 6 7 8 and 9 if the latter type 9 has a non circular cross section The third node is used for the discrete beam type 6 if and only if SCOOR is set to 2 0 in the SECTION_BEAM input but even in this case it is optional 12 3 ELEMENT ELEMENT VARIABLE RTI RT2 RRI RR2 LOCAL PARMI PARM2 12 4 ELEMENT DESCRIPTION Release conditions for translations at nodes N1 and N2 respectively 0 no translational degrees of freedom are released EQ 1 x translational degree of freedom EQ 2 y translational degree of freedom EQ 3 z translational degree of freedom EQ 4 x and y translational degrees of freedom EQ 5 y and z translational degrees of freedom EQ 6 z and x translational degrees of freedom EQ 7 x y and z translational degrees of freedom 3DOF This option does not apply to the spot weld beam type 9 Release conditions for rotations at nodes N1 and N2 respectively EQ 0 no rotational degrees of freedom are released EQ 1 x rotational degree of freedom EQ 2 y rotational degree of freedom EQ 3 z rotational degree of freedom EQ 4 x and y rotational degrees of freedom
18. Remarks 1 There are multiple solver options for a variety of flow related physics in LS DYNA The selection of the incompressible low Mach flow physics and related flow solver is determined by the INSOL input on the CONTROL CFD GENERAL keyword Currently there are two valid values for INSOL INSOL 1 selects the explicit time integrator that requires the use of a lumped mass matrix In this case the IMASS THETAK THETAB THETAA and THETAF variables associated with the CONTROL MOMENTUM keyword are ignored INSOL 3 selects the semi implicit projection algorithm which makes use of these variables 2 This option is only available for the semi implicit implicit solution algorithm INSOL 3 7 16 CONTROL LS DYNA Version 960 CONTROL CONTROL CFD MOMENTUM Purpose Set the solver parameters to be used for the momentum equations in the Navier Stokes solver Card 1 is used to control the time integrator and advective transport options Card 2 is used to set the linear solver options such as the maximum iteration count and interval to check the convergence criteria Card Format Card 1 1 2 3 4 5 6 7 8 E Jo oom on om PE PEE ET me EI 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IMASS Select the mass matrix formulation to use EQ 0 IMASS 1 default EQ 1 Lumped mass matrix EQ 2 Consistent mass matrix EQ 3 Higher order mass matrix
19. X Initial x coordinate Y Initial y coordinate X Initial z coordinate LS DYNA Version 960 9 27 DATABASE DATABASE 9 28 DATABASE LS DYNA Version 960 DEFINE DEFINE The keyword DEFINE provides a way of defining boxes coordinate systems load curves tables and orientation vectors for various uses The keyword cards in this section are defined in alphabetical order DEFINE BOX DEFINE BOX ADAPTIVE DEFINE BOX COARSEN DEFINE BOX DRAWBEAD DEFINE COORDINATE NODES DEFINE COORDINATE SYSTEM DEFINE COORDINATE VECTOR DEFINE CURVE DEFINE CURVE FEEDBACK DEFINE CURVE SMOOTH DEFINE CURVE TRIM DEFINE SD ORIENTATION DEFINE TABLE DEFINE TRANSFORMATION DEFINE VECTOR An additional option TITLE may be appended to all the DEFINE keywords If this option is used then an addition line is read for each section in 80a format which can be used to describe the defined curve table etc At present LS DYNA does make use of the title Inclusion of titles gives greater clarity to input decks Examples for the DEFINE keyword can be found at the end of this section LS DYNA Version 960 10 1 DEFINE DEFINE DEFINE BOX Purpose Define a box shaped volume Two diagonally opposite corner points of a box are specified in global coordinates The box volume is then used for various specifications e g velocities contact etc Card Format 1 2 3 4 5 6 7 8 EHEN EHEN EN EIERN
20. ditate erbe d re nop oL Pet iners 6 52 CONTAGT TD 23 a a ERE RR ERI ORO NM 6 55 CONTACT 2D OPTION2 2 6 56 CONTROL EHI EDU VAR Ve EE DU RB I BE 7 1 TCONTROL sAC CURACY 2 ee ana tebe ee tote wee tides EPA oT RE ERE 7 3 CONTROL ADABSTED eie rhe tpe ade ep E E erar REESE MERI e 7 5 CONTROL ADAPTIVE eee a x e Rt RE ee ide 7 6 CONTROL ALE nen aan De eae eee Re ue TU E cag ae e 7 10 CONTROI BULK VISCOSITY he rte RN eerte E S 7 12 CONTROL CED AUTO 2 20 40er T E ECT 7 13 CONTROL CED GENERAL ite ee pie tette au a kn 7 15 CONTROL CFD MOMENTUM isisi niet rope tap pee ee e sn ni 7 17 CONTROE CEDZPRESSURE 1 en ae de TE Obr o Robes Tett aue tpa des 7 20 CONTROL CFD TRANSPORT iuc 2222220 pete etre ti ted dre Rire ERR Ra 7 22 CONTROL CED TURBUFEENCE sere E aee 7 26 CONTROL COARSEN iiieest et eis aan nn 1 27 CONTROL CONTACT ee eek rest be 1 29 CONTROL COUPLING 22 332 d toii dedi sche eltern ee 7 34 LS DYNA Version 960 iii TABLE OF CONTENTS CONTROLSERU UU 7 36 CONTROL DYNAMIC RELAXATION teo aan 7 37 CONTROL ENERQGY e Stine lei Reken kenn eier 1 39 CONTROL EXPLOSIVE 5 7 40 CONTROL HOURGLASS OPTION iiti ninani n ranae inene ian 7 41 CONTROE IMPLICIT AU O
21. CONTROL_COUPLING CONTROL_CPU CONTROL_DYNAMIC_RELAXATION CONTROL_ENERGY CONTROL_EXPLOSIVE_SHADOW CONTROL_HOURGLASS_ OPTION CONTROL_IMPLICIT_AUTO CONTROL_IMPLICIT_DYNAMICS CONTROL_IMPLICIT_EIGENVALUE CONTROL_IMPLICIT_GENERAL CONTROL_IMPLICIT_SOLUTION CONTROL_IMPLICIT_SOLVER CONTROL_IMPLICIT_STABILIZATION CONTROL_OUTPUT CONTROL_PARALLEL CONTROL_RIGID LS DYNA Version 960 7 1 CONTROL CONTROL CONTROL_SHELL CONTROL_SOLID CONTROL_SOLUTION CONTROL_SPH CONTROL_STRUCTURED_ OPTION CONTROL_SUBCYCLE CONTROL_TERMINATION CONTROL_THERMAL_NONLINEAR CONTROL_THERMAL_SOLVER CONTROL_THERMAL_TIMESTEP CONTROL_TIMESTEP LS DYNA s implicit mode may be activated in two ways Using the CONTROL_IMPLICIT_GENERAL keyword a simulation may be flagged to run entirely in implicit mode Alternatively an explicit simulation may be seamlessly switched into implicit mode at a specific time using the INTERFACE SPRINGBACK SEAMLESS keyword The seamless switching feature is intended to simplify metal forming springback calculations where the forming phase can be run in explicit mode followed immediately by an implicit static springback simulation In case of difficulty restart capability is supported Seven keywords are available to support implicit analysis Default values are carefully selected to minimize input necessary for most simulations These are summarized below CONTROL_IMPLICIT_GENERAL Activates impl
22. Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION CPUTIM Seconds of cpu time EQ 0 0 no cpu time limit set Remarks The CPU time limit applies to the current phase of the analysis or restart The limit is not checked until after the initialization stage of the calculation Upon reaching the cpu limit the code will output a restart dump file and terminate The CPU limit can also be specified on the input control line to LS DYNA If a value is specified on both the control line and in the input deck the minimum value will be used 7 36 CONTROL LS DYNA Version 960 CONTROL CONTROL_DYNAMIC_RELAXATION Purpose Define controls for dynamic relaxation Important for stress initialization Card Format NRCYCK DRTOL DRFCTR DRTERM TSSFDR IRELAL EDTTL IDRFLG VARIABLE DESCRIPTION NRCYCK Number of iterations between convergence checks for dynamic relaxation option default 250 DRTOL Convergence tolerance for dynamic relaxation option default 0 001 DRFCTR Dynamic relaxation factor default 995 DRTERM Optional termination time for dynamic relaxation Termination occurs at this time or when convergence is attained default infinity TSSFDR Scale factor for computed time step during dynamic relaxation If zero the value is set to TSSFAC defined on CONTROL_TIMESTEP After converging the scale factor is reset to TSSFAC IRELAL Automatic control for dynamic relaxation option based on algorithm
23. Cards 2 3 4 OPTION GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIBEG BIEND B2BEG B2END B3BEG B3END B4BEG B4END Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options ALL ELEM DELEM PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID All solid sets should have a unique set ID Kl First element ID K2 Second element ID K8 Eighth element ID BNBEG First solid element ID in block N BNEND Last solid element ID in block n All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all input is read so that gaps in the element numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not element ID s OPTION Option for GENERAL See table below 24 24 SET LS DYNA Version 960 SET VARIABLE DESCRIPTION ELE Specified entity Each card must have the option specified See table below OPTION ENTITY define up to 7 FUNCTION All solid elements will be included in the set el e2 e3 e4 e5 e7 Elements e1 e2 e3 will be included DELEM el e2 e3 e4 e5 e6 e7 Elements el e2 e3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 will be included DPART pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 previousl
24. EQ 1 Explicit transient incompressible Navier Stokes EQ 3 Semi implicit fully implicit transient incompressible Navier Stokes using staggered velocity pressure DTINIT Set the initial time step for the Navier Stokes and all auxiliary transport equations The time step is computed based on either the prescribed CFL number INSOL 3 or stability INSOL 1 unless ICKDT 0 or IAUTO 3 on the CONTROL_CFD_AUTO keyword CFL Set the maximum advective grid CFL number to be maintained during the computation EQ 0 CFL 0 9 default for INSOL 1 CFL 2 0 default for INSOL 3 ICKDT Set the interval to check and report the grid Reynolds and advective CFL numbers ICKDT lt 0 checks and reports the grid Reynolds and advective CFL numbers but does not modify the time step ICKDT gt 0 modifies the time step according to the prescribed CFL limit and any required stability limits The report of the grid Reynolds and CFL numbers to the screen may be toggled with the grid sense switch EQ 0 ICKDT 10 default LS DYNA Version 960 7 15 CONTROL CONTROL IACURC Activate the use of full quadrature for certain terms in the momentum and transport equations The accuracy flag improves the accuracy of body force calculations and certain advective convective terms with a modest increase in computational time EQ 0 don t use the increased quadruature rules default EQ 1 use the increased quadrature on advective convective and body force terms
25. EQ 7 29 6 RESTART no constraints constrained x rotation constrained y rotation constrained z rotation constrained x and y rotations constrained y and z rotations constrained z and x rotations constrained x y and z rotations LS DYNA Version 960 RESTART The RIGID BODY STOPPER option allows existing stoppers to be redefined This input terminates when the next card is encountered See CONSTRAINED RIGID BODY STOPPERS New stopper definitions cannot be introduced in this section Existing stoppers can be modified Card Formats Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of master rigid body see PART LCMAX Load curve ID defining the maximum coordinate as a function of time EQ 0 no limitation of the maximum displacement New curves can be defined by the DEFINE_CURVE within the present restart deck LCMIN Load curve ID defining the minimum coordinate as a function of time EQ 0 no limitation of the minimum displacement New curves can be defined by the DEFINE_CURVE within the present restart deck PSIDMX Optional part set ID of rigid bodies that are slaved in the maximum coordinate direction to the master rigid body This option requires additional input by the SET PART definition LS DYNA Version 960 29 7 RESTART RESTART VARIABLE PSIDMN LCVMNX DIR BIRTH DEATH Remarks DESCRIPTION Opti
26. INITIAL INITIAL_DETONATION Purpose Define points to initiate the location of high explosive detonations in part ID s which use the material type 8 MAT HIGH EXPLOSIVE BURN Also see CONTROL EXPLOSIVE SHADOW Card Format Card 1 1 2 3 4 5 6 7 8 mee ete al N Optional card required if and only if PID 1 Card 2 1 2 3 4 5 6 7 8 efor VARIABLE DESCRIPTION PID Part ID of high explosive material to be lit see PART However two other options are available EQ 1 an acoustic boundary also BOUNDARY USA SURFACE EQ 0 all high explosive materials are considered X x coordinate of detonation point see Figure 16 1 Y y coordinate of detonation point Z z coordinate of detonation point 16 4 INITIAL LS DYNA Version 960 INITIAL VARIABLE DESCRIPTION LT Lighting time for detonation point This time is ignored for an acoustic boundary PEAK Peak pressure of incident pressure pulse see remark below DECAY Decay constant T XS x coordinate of standoff point see Figure 16 1 YS y coordinate of standoff point ZS z coordinate of standoff point NID Reference node ID near structure Remarks For solid elements not acoustic two options are available If the control card option CONTROL EXPLOSIVE 5 is not used the lighting time for an explosive element is computed using the distance from the center of the element to the nearest det
27. SDRC IDEAS Universal File 2430 755 791 time variation set le 0 0 time variation set gt 0 0 790 load type eq 1 27 4 TRANSLATE LS DYNA Keyword PART amp SECTION BOUNDARY_SPC_NODE BOUNDARY_SPC_NODE BOUNDARY_PRESCRIBED_ MOTION_NODE LOAD_NODE LS DYNA Version 960 TRANSLATE TRANSLATE_NASTRAN Purpose Provide a convenient route to read in NASTRAN input deck as part of the LSDYNA keyword input This keyword can appear more than once anywhere in the input Also see remarks below Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION FILE Filename of the NASTRAN input deck The following table lists supported NASTRAN keywords Version NASTRAN INPUT FILE LS DYNA Keyword All N Type NODE Val1 Val2 Val3 NODE All EN Type 11 12 13 14 15 16 17 18 ELEMENT All BEGIN BULK All GRID NODE All CORD2R DEFINE_COORDINATE_SYSTEM All CHEXA CPENTA CTETRA ELEMENT_SOLID All PSOLID PART and SECTION_SOLID All CQUAD4 CTRIA3 ELEMENT_SHELL All PSHELL PART and SECTION_SHELL All CBAR CBEAM ELEMENT_BEAM All CELAS1 CVISC CDAMPI ELEMENT_DISCRETE All CONM2 ELEMENT_MASS All MATI MAT_ELASTIC All SPC SPCI BOUNDARY_SPC_OPTION LS DYNA Version 960 27 5 TRANSLATE TRANSLATE Version NASTRAN INPUT FILE LS DYNA Keyword All RBE2 CONSTRAINED_NODE_SET or CONSTRAINED_NODAL_RIGID_BODY All ENDDATA END Remarks 1 Both small and large field fixed NASTRAN formats are suppor
28. This section applies to various methods of specifying either fixed or prescribed boundary conditions For compatibility with older versions of LS DYNA it is still possible to specify some nodal boundary conditions in the NODE card section COMPONENT This section contains analytical rigid body dummies that can be placed within vehicle and integrated implicitly CONSTRAINED This section applies constraints within the structure between structural parts For example nodal rigid bodies rivets spot welds linear constraints tying a shell edge to a shell edge with failure merging rigid bodies adding extra nodes to rigid bodies and defining rigid body joints are all options in this section CONTACT This section is divided in to three main sections The CONTACT section allows the user to define many different contact types These contact options are primarily for treating contact of deformable to deformable bodies single surface contact in deformable bodies deformable body to rigid body contact and tying deformable structures with an option to release the tie based on plastic strain The 1 14 INTRODUCTION LS DYNA Version 960 INTRODUCTION surface definition for contact is made up of segments on the shell or solid element surfaces The keyword options and the corresponding numbers in previous code versions are STRUCTURED INPUT TYPE ID KEYWORD NAME SLIDING_ONLY SLIDING_ONLY_PENALTY TIED_SURFACE_TO_SURFACE SURFACE_TO_SURFACE AU
29. is the specific internal energy of the gas and y is the ratio of the specific heats where Cy is the specific heat at constant volume and Cp is the specific heat at constant pressure A pressure relation is defined 1 16 AIRBAG LS DYNA Version 960 AIRBAG where pe is the external pressure and is the internal pressure in the bag critical pressure relationship is defined as Ya 2 0 y 1 where is the ratio of specific heats If QSQai Qc Qai Wang and Nefske define the mass flow through the vents and leakage by My Ta ae 2 07 and 2 y R rj My Er 2 Q d 2 It must be noted that the gravitational conversion constant has to be given in consistent units As an alternative to computing the mass flow out of the bag by the Wang Nefske model a curve for the exit flow rate depending on the internal pressure can be taken Then no definitions for C23 LCC23 A23 LCA23 CP23 LCCP23 AP23 and LCAP23 are necessary The airbag inflator assumes that the control volume of the inflator is constant and that the amount of propellant reacted can be defined by the user as a tabulated curve of fraction reacted versus time A pressure relation is defined he Ae Oi x E p y l where p is a critical pressure at which sonic flow occurs p is the inflator pressure The exhaust pressure is given by Dp f Dp 2p P P lt LS DYNA Vers
30. 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IRID Integration rule ID IRID refers to IRID on SECTION_SHELL card NIP Number of integration points ESOP Equal spacing of integration points option 0 integration points are defined below EQ 1 integration points are equally spaced through thickness such that the shell is subdivided into NIP layers of equal thickness 5 Coordinate of integration point in range 1 to 1 WF Weighting factor This is typically the thickness associated with the integration point divided by actual shell thickness i e the weighting factor for the ith integration point as seen in Figure 17 4 17 6 INTEGRATION LS DYNA Version 960 INTEGRATION VARIABLE DESCRIPTION PID Optional part ID if different from the PID specified on the element card The material type is not allowed to change see PART The average mass density for the shell element is based on a weighted average of the density of each layer that is used through the thickness When modifying the constitutive constants throuigh the thickness it is often necessary to defined unique part IDs without elements that are referenced only by the user integration rule These additional part IDs only provide a density and constitutive constants with local material axes if used and orientation angles taken from the PID referenced on the element card In defining a PID for an integration point it is okay to reference a solid elemen
31. 1 of 1 for the SET option 1 2 3 4 5 6 7 8 NSID HSID BSID SSID TSID DSID EN ITYPE VARIABLE PSID XCT YCT ZCT XCH YCH ZCH XHEV YHEV ZHEV LENL LENM NSID HSID BSID 9 12 DATABASE DESCRIPTION Part set ID If zero all parts are included x coordinate of tail of any outward drawn normal vector N originating on wall tail and terminating in space head see Figure 9 1 y coordinate of tail of normal vector N z coordinate of tail of normal vector N x coordinate of head of normal vector N y coordinate of head of normal vector N z coordinate of head of normal vector N x coordinate of head of edge vector L y coordinate of head of edge vector L Z coordinate of head of edge vector L Length of edge a in L direction Length of edge b in M direction Nodal set ID see SET NODE OPTION Solid element set ID see SET SOLID Beam element set ID see SET BEAM LS DYNA Version 960 VARIABLE SSID TSID DSID ID ITYPE LS DYNA Version 960 DATABASE DESCRIPTION Shell element set ID see SHELL OPTION Thick shell element set ID see SET TSHELL Discrete element set ID see SET DISCRETE Rigid body see RIGID type 20 or accelerometer ID see ELEMENT SEATBELT ACCELEROMETER The force resultants are output in the updated local system of the rigid body or accelerometer Flag for local system type EQ 0 rigid body EQ 1 acceleromet
32. 4 Related switch set The related switch set 1s another automatic switch set that must be activated before this part switch can take place EQ 0 no related switch set Define a pair of related switches EQ 0 not paired EQ 1 paired with switch set RELSW and is the Master switch EQ 1 paired with switch set RELSW and is the Slave switch Flag to delete or activate nodal rigid bodies If nodal rigid bodies or generalized weld definitions are active in the deformable bodies that are switched to rigid then the definitions should be deleted to avoid instabilities EQ 0 no change EQ 1 delete EQ 2 activate Flag to delete or activate nodal constraint set If nodal constraint spotweld definitions are active in the deformable bodies that are switched to rigid then the definitions should be deleted to avoid instabilities EQ 0 no change EQ 1 delete EQ 2 activate 11 4 DEFORMABLE TO RIGID LS DYNA Version 960 DEFORMABLE TO RIGID VARIABLE DESCRIPTION RWF Flag to delete or activate rigid walls EQ 0 no change EQ 1 delete EQ 2 activate DTMAX Maximum permitted time step size after switch D2R Number of deformable parts to be switched to rigid plus number of rigid parts for which new master slave rigid body combinations will be defined EQ 0 no parts defined R2D Number of rigid parts to be switched to deformable EQ 0 no parts defined Remarks 1 Only surface to surface and n
33. ALE ALE VARIABLE DESCRIPTION ID Node group ID for PRTYPE 3 or 7 see REFERENCE SYSTEM GROUP NID1 NID12 User specified nodes Remark For PRTYPE 3 the ALE mesh is forced to follow the motion of a coordinate system which is defined by three nodes NID1 NID2 NID3 These nodes are located at x x and x respectively The axes of the coordinate system x y and z are defined as x l z x X x x lx x x x y z x x For PRTYPE 7 the ALE mesh is forced to move and expand so as to enclose up to twelve user defined nodes NIDI NID12 2 10 ALB LS DYNA Version 960 ALE ALE REFERENCE SYSTEM SWITCH Purpose This command allows for switching between Lagrangian Eulerian and ALE formulations during the simulation Card Format Card 1 1 2 3 IT LII Card Format Card 2 1 2 3 Card Format Card 3 1 2 3 4 5 6 7 8 Variable TYPE7 TYPE8 LS DYNA Version 960 2 11 ALE ALE Card Format Card 4 1 2 3 4 5 6 7 8 wes In fom fom os oe om oe Default none none none none none none none none VARIABLE DESCRIPTION ID Switch list ID see ALE_REFERENCE_SYSTEM_GROUP T1 T7 Times for switching reference system type TYPEI TYPE8 Reference system types EQ 0 Eulerian EQ 1 Lagrangian EQ 2 Normal ALE mesh smoothing EQ 3 Prescribed motion following load curves see ALE REF
34. CONTROL TERMINATION control card For both options the input is identical Card Format Default 29 34 RESTART LS DYNA Version 960 RESTART For the NODE option VARIABLE NID STOP MAXC MINC DESCRIPTION Node ID Stop criterion EQ 1 global x direction EQ 2 global y direction EQ 3 global z direction EQ 4 stop if node touches contact surface Maximum most positive coordinate options 1 2 and 3 above only Minimum most negative coordinate options 1 2 and 3 above only For the BODY option VARIABLE PID STOP MAXC MINC LS DYNA Version 960 DESCRIPTION Part ID of rigid body Stop criterion EQ 1 global x direction EQ 2 global y direction EQ 3 global z direction EQ 4 stop if displacement magnitude is exceeded Maximum most positive displacement options 1 2 3 and 4 EQ 0 0 MAXC set to 1 0e21 Minimum most negative displacement options 1 2 and 3 above only EQ 0 0 MINC set to 1 0e21 29 35 RESTART RESTART TITLE Purpose Define job title Card Format Type Default LS DYNA USER INPUT VARIABLE DESCRIPTION TITLE Heading to appear on output 29 36 RESTART LS DYNA Version 960
35. DESCRIPTION max 0 0 0 FS are the interface normal and shear stresses and norma 2 2 failure occurs if E 1 gt 0 where o shear Normal tensile stress at failure Shear stress at failure Exponential decay coefficient The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact FD FS C Coefficient for viscous friction This is necessary to limit the friction force to a maximum A limiting force is computed VC A Acont being im cont the area of the segment contacted by the node in contact The suggested 43 value for VC is to use the yield stress in shear VC where is the yield stress of the contacted material Viscous damping coefficient in percent of critical In order to avoid undesirable oscillation in contact e g for sheet forming simulation a contact damping perpendicular to the contacting surfaces is applied Damping coefficient amp 4 eg VDC 20 Eni following fashion by LS DYNA 2mw min m is determined in the mass of master master resp slave node m slave m m w k Se master amp interface stiffness m slave Master Small penetration in contact search option If the slave node penetrates more than the segment thickness times the factor XPENE see CONTROL_ CONTACT the penetration is ignored and the slave node is set free The thi
36. For example 2D axisymmetric calculations can use either element types 14 or 15 but these element types must not be mixed together Likewise the plane strain element type must not be used with either the plane stress element or the axisymmetric element types In 3D the different shell elements types i e 1 11 and 16 can be freely mixed together Shear corection factor which scales the transverse shear stress The shell formulations in LS DYNA with the exception of the BCIZ and DK elements are based on a first order shear deformation theory that yields constant transverse shear strains which violates the condition of zero traction on the top and bottom surfaces of the shell The shear correction factor is attempt to compensate for this error A suggested value is 5 6 for isotropic materials This value is incorrect for sandwich or laminated shells consequently laminated sandwich shell theory is now used in some of the constitutive model Number of through thickness integration points Either Gauss default or Lobatto integration can be used The flag for Lobatto integration can be set on the control card CONTROL_SHELL The location of the Gauss and Lobatto integration points are tabulated below EQ 0 0 set to 2 integration points for shell elements EQ 1 0 1 point no bending EQ 2 0 2 point EQ 3 0 3 point EQ 4 0 4 point EQ 5 0 5 point EQ 6 0 6 point EQ 7 0 7 point EQ 8 0 8 point EQ 9 0 9 point EQ 10 10 poin
37. Generally default settings can be used so these keywords need not be included in the input deck To obtain accurate springback solutions a nonlinear springback analysis must be performed In many simulations this iterative equilibrium search will converge without difficulty If the springback simulation is particularly difficult either due to nonlinear deformation nonlinear material response or numerical precision errors a multi step springback simulation will be automatically invoked In this approach the springback deformation is divided into several smaller more manageable steps Two specialized features in LS DYNA are used to perform multi step springback analyses The addition and gradual removal of artificial springs is performed by the artificial stabilization feature Simultaneously the automatic time step control is used to guide the solution to the termination time as quickly as possible and to persistently retry steps where the equilibrium search has failed By default both of these features are active during a seamless springback simulation However the default method attempts to solve the springback problem in a single step If this is successful the solution will terminate normally If the single step springback analysis fails to converge the step size will be reduced and artificial stabilization will become active Defaults for these features be changed using the CONTROL IMPLICIT GENERAL CONTROL IMPLICIT AUTO
38. Inflator orifice coefficient Inflator orifice area Inflator volume Inflator density Inflator temperature Load curve defining burn fraction versus time Ambient temperature First heat capacity coefficient of inflator gas e g Joules mole K Second heat capacity coefficient of inflator gas e g Joules mole K7 1 15 AIRBAG AIRBAG VARIABLE DESCRIPTION MW Molecular weight of inflator gas e g Kg mole GASC Universal gas constant of inflator gas e g 8 314 Joules mole K TDP Time delay before initiating exit flow after pop pressure is reached AXP Pop acceleration magnitude in local x direction EQ 0 0 Inactive AYP Pop acceleration magnitude in local y direction EQ 0 0 Inactive AZP Pop acceleration magnitude in local z direction EQ 0 0 Inactive AMAGP Pop acceleration magnitude EQ 0 0 Inactive TDURP Time duration pop acceleration must be exceeded to initiate exit flow This is a cumulative time from the beginning of the calculation i e it is not continuous TDA Time delay before initiating exit flow after pop acceleration is exceeded for the prescribed time duration RBIDP Part ID of the rigid body for checking accelerations against pop accelerations Remarks The gamma law equation of state for the adiabatic expansion of an ideal gas is used to determine the pressure after preload II R where is the pressure p is density
39. LS DYNA Version 960 SECTION DESCRIPTION Section ID SECID is referenced on the PART card and must be unique Element formulation options see remark 3 below EQ 0 1 point corotational for MAT MODIFIED HONEYCOMB See remark 4 below EQ 1 constant stress solid element default EQ 2 fully integrated S R solid See remark 5 below EQ 3 fully integrated quadratic 8 node element with nodal rotations EQ 4 S R quadratic tetrahedron element with nodal rotations EQ 5 1 point ALE EQ 6 1 point Eulerian EQ 7 1 point Eulerian ambient EQ 8 acoustic EQ 9 1 point corotational for MAT_MODIFIED_HONEYCOMB See remark 4 below EQ 10 1 point tetrahedron EQ 11 1 point ALE multi material element EQ 12 1 point integration with single material and void EQ 13 1 point nodal pressure tetrahedron for bulk forming EQ 14 8 point acoustic EQ 15 2 point pentahedron element EQ 18 8 point enhanced strain solid element for linear statics only EQ 31 1 point Eulerian Navier Stokes EQ 32 8 point Eulerian Navier Stokes Ambient Element type Can be defined for ELFORM 7 11 and 12 EQ 1 temperature not currently available EQ 2 pressure and temperature not currently available EQ 3 pressure outflow EQ 4 pressure inflow Default for ELFORM 7 Smoothing weight factor Simple average EQ 1 turn smoothing off Smoothing weight factor Volume weighting Smoothing weight factor Isoparametric Smoothing
40. PARM4 Based on beam type Type EQ 1 beam thickness t direction at node 2 Type EQ 2 Irr Type EQ 3 not used Type EQ 4 beam thickness t direction at node 2 Type EQ 5 beam thickness t direction at node 2 Type EQ 6 area Type EQ 7 not used Type EQ 8 not used Type EQ 9 beam thickness t direction at node 2 PARMS Based on beam type Type EQ 1 not used Type EQ 2 shear area Type EQ 3 not used Type EQ 4 not used Type EQ 5 not used Type EQ 6 offset Type EQ 7 not used Type EQ 8 not used Type EQ 9 not used PIDI Optional part ID for spot weld element type 9 PID2 Optional part ID for spot weld element type 9 Remarks 1 A plane through and defines the orientation of the principal r s plane of the beam see Figure 12 1 25 This option applies to all three dimensional beam elements The released degrees of freedom can be either global the default or local relative to the local beam coordinate system see Figure 12 1 A local coordinate system is stored for each node of the beam element and the orientation of the local coordinate systems rotates with the node To properly track the response the nodal points with a released resultant are automatically replaced with new nodes to accommodate the added degrees of freedom Then constraint equations are used to join the nodal points together with the proper release conditions imposed Consequently nodal points which belong to beam elements which have releas
41. Purpose Define mass weighted nodal damping that applies globally to the nodes of deformable bodies and to the mass center of the rigid bodies Card Format 1 2 3 4 5 6 7 8 efe VARIABLE DESCRIPTION LCID Load curve ID which specifies node system damping 0 a constant damping factor as defined by VALDMP is used EQ n system damping is given by load curve n The damping force applied to each node is f d t mv where d t is defined by load curve n VALDMP System damping constant d this option is bypassed if the load curve number defined above is non zero STX Scale factor on global x translational damping forces LS DYNA Version 960 8 1 DAMPING DAMPING VARIABLE DESCRIPTION STY Scale factor on global y translational damping forces STZ Scale factor on global z translational damping forces SRX Scale factor on global x rotational damping moments SRY Scale factor on global y rotational damping moments SRZ Scale factor on global z rotational damping moments Remarks 1 This keyword is also used for the restart see RESTART 2 If STX STY STZ SRX SRY SRZ 0 0 in the input above all six values are defaulted to unity With mass proportional system damping the acceleration is computed as F zu where M is the diagonal mass matrix P is the external load vector F is the internal load vector and is the
42. Remarks The Sack equation of state defines pressure as A A V B B 2 1 E P v v and is used for detonation products of high explosives LS DYNA Version 960 13 5 EOS EOS EOS_GRUNEISEN This is Equation of state Form 4 Card Format 1 2 3 4 Card 2 VARIABLE DESCRIPTION EOSID Equation of state ID 51 52 53 GAMAO EO Initial internal energy vo Initial relative volume 13 6 EOS LS DYNA Version 960 EOS Remarks The Gruneisen equation of state with cubic shock velocity particle velocity defines pressure for compressed materials as Be po uli 1 2 u 8 zx 2 2 2 5 5 4 5 Yo tau E and for expanded materials as P P Cp V au E where is the intercept of the vs vp curve 51 52 and 53 the coefficients of the slope of the vs p 1 0 Vp curve Yo is the Gruneisen gamma a is the first order volume correction to yo and u LS DYNA Version 960 13 7 EOS EOS EOS_RATIO_OF_POLYNOMIALS This is Equation of state Form 5 Card Format I10 for card 1 4E20 0 all following cards Card 1 1 Card 2 1 2 3 4 Card 3 1 2 3 4 Card 4 1 2 3 4 Card 5 1 2 3 4 13 8 EOS LS DYNA Version 960 EOS Card 6 1 2 3 4 Card 7 1 2 3 4 Card 8 1 2 3 4 Card 9 1 2 Card 10 1 2 3 4 LS DYNA Version 960 13 9 EOS EOS VARIABLE DESCRIPTION EOSID Equ
43. The contents of the files are given in Table 9 1 for nodes Table 9 2 for solid elements Table 9 3 for shells and thick shells and Table 9 4 for beam elements In the binary file D3THDT the contents may be extended or reduced with the DATABASE_EXTENT_BINARY definition 9 22 DATABASE LS DYNA Version 960 DATABASE Card Format options NODE_LOCAL and NODE_SET_LOCAL Cards 1 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ID NODE NODE_SET set ID The contents of the files are given in Table 9 1 for nodes See the remark below concerning accelerometer nodes CID Coordinate system ID for nodal output See DEFINE COORDINATE options REF Output reference EQ 0 Output is in the local system fixed for all time from the beginning of the calculation EQ 1 Output is in the local system which is defined by the DEFINE COORDINATE NODES The local system can change orientation depending on the movement of the three defining nodes The defining nodes can belong to either deformable or rigid parts EQ 2 Output is relative to the local system which is defined by the DEFINE COORDINATE NODES option The local system can change orientation depending on the movement of the three defining nodes If dynamic relaxation is used the reference location is reset when convergence is achieved Remarks 1 Ifa node belongs to an accelerometer see ELEMENT SEATBELT ACCELEROMETER and if it also appears as an active node in the NODE LOCAL or NOD
44. VARIABLE DESCRIPTION PSID PID Part set ID or part ID see also SET_PART Remark This void option and multiple materials per element see ALE_MULTI MATERIAL_GROUP incompatible and cannot be used together in the same run LS DYNA Version 960 16 25 INITIAL INITIAL INITIAL_VOLUME_FRACTION Purpose Define initial volume fraction of different materials in multi material ALE or in single material and void models Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION EID Element ID VFI Volume fraction of multi material group 1 VF2 Volume fraction of multi material group 2 Only needed in simulations with 3 material groups Otherwise VF2 1 VF1 16 26 INITIAL LS DYNA Version 960 INTEGRATION INTEGRATION INTEGRATION_BEAM Purpose Define user defined through the thickness integration rules for the beam element Card Format Card 1 1 2 3 4 5 6 7 8 Define the following card if and only if ICST gt 0 1 2 3 4 5 6 7 8 P E Define NIP cards below Skip if NIP 0 1 2 3 4 5 6 7 8 LS DYNA Version 960 17 1 INTEGRATION INTEGRATION VARIABLE IRID NIP RA ICST TF SREF TREF WF 17 2 INTEGRATION DESCRIPTION Integration rule ID IRID refers to IRID on SECTION_BEAM card Number of integration points see also ICST Relative area of cross section i e the actual cross sectional area divided by the area de
45. YC y center yc see remarks below ZC z center 2 See remarks below AX x direction for local axis A Ax see remarks below AY y direction for local axis A Ay see remarks below AZ z direction for local axis A see remarks below BX x direction for local axis B Bx see remarks below BY y direction for local axis B By see remarks below BZ z direction for local axis B B see remarks below LS DYNA Version 960 6 41 CONTACT CONTACT Remarks 1 The coordinates Xc Ye Zc are the positions of the local origin of the geometric entity in global coordinates The entity s local A axis is determined by the vector Ax Ay Az and the local B axis by the vector Bx By Bz 2 Cards 3 and 4 define a local to global transformation The geometric contact entities are defined in a local system and transformed into the global system For the ellipsoid this is necessary because it has a restricted definition for the local position For the plane sphere and cylinder the entities can be defined in the global system and the transformation becomes Zc 2 0 0 0 Ax Ay Az 1 0 0 and Bx By Bz 0 1 0 6 42 CONTACT LS DYNA Version 960 CONTACT Card 5 Format Card 5 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION INOUT In out flag Allows contact from the inside or the outside default of the entity 0 slave nodes exist outside of the entity EQ 1 slave nodes exist inside the entity Gl En
46. box material limited automatic contact for shells automatic contact for shells no additional input required automatic single surface with beams and arbitrary orientations surface to surface eroding contact node to surface eroding contact single surface eroding contact surface to surface symmetric constraint method Taylor and Flanagan 1989 node to surface constraint method Taylor and Flanagan 1989 rigid body to rigid body contact with arbitrary force deflection curve rigid nodes to rigid body contact with arbitrary force deflection curve edge to edge draw beads Interface friction can be used with most interface types The tied and sliding only interface options are similar to the two dimensional algorithm used in LS DYNA2D Hallquist 1976 1978 1980 Unlike the general option the tied treatments are not symmetric therefore the surface which is more coarsely zoned should be chosen as the master surface When using the one way slide surface with rigid materials the rigid material should be chosen as the master surface For geometric contact entities contact has to be separately defined It must be noted that for the contact of a rigid body with a flexible body either the sliding interface definitions as explained above or the geometric contact entity contact can be used Currently the geometric contact entity definition is recommended for metalforming problems due to high accuracy and computational efficiency LS DYN
47. data global data like total internal and kinetic energy material energies nodal interface forces resultant interface forces single point constraint forces as well as files that are compatible with MOVIE BYU and the Cray Research developed post processor MPGS A SMUG animator database and a NASTRAN BDF file is written for users at General Motors Each ASCII database 15 written at its own unique output interval defined in the user input LS DYNA Version 960 1 33 INTRODUCTION INTRODUCTION File Organization plotfile ASCII Experimental G Database Dat Iu POST LS TAURUS save file far PostScript commands lot S tsave HPGL plot videooutput HP Laserjet PAL NTSC pel plot Figure 1 4 1 34 INTRODUCTION LS DYNA Version 960 INTRODUCTION EXECUTION SPEEDS The relative execution speeds for various elements in LS DYNA are tabulated below Element Type Relative Cost 8 node solid with 1 point integration and default 4 hourglass control as above but with Flanagan Belytschko hourglass control constant stress and Flanagan Belytschko hourglass control i e the Flanagan Belytschko element 4 node Belytschko Tsay shell with four thickness integration points 4 node Belytschko Tsay shell with resultant plasticity BCIZ triangular shell with four thickness integration points triangular shell with four thickness integration points 2 node Hughes Liu beam with four integration points 2
48. dt h t is the smoothing length div v is the divergence of the flow The smoothing length increases when particles separate from each other and reduces when the concentration of particles is important It varies to keep the same number of particles in the neighborhood The smoothing length varies between the minimum and maximum values HMIN h lt h t lt HMAX h Defining a value of 1 for HMIN and 1 for HMAX will result in a constant smoothing length in time and space 2 SPH is implemented for explicit applications 23 24 SECTION LS DYNA Version 960 SECTION SECTION_TSHELL Purpose Define section properties for thick shell elements Card Format Card 1 eg ee Optional Section Cards if ICOMP 1 define NIP angles putting 8 on each card Cards 2 3 VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique ELFORM Element formulation EQ 1 one point reduced integration default EQ 2 selective reduced 2 x 2 in plane integration EQ 3 assumed strain 2 x 2 in plane integration see remark below SHRF Shear factor A value of 5 6 is recommended NIP Number of through shell thickness integration points 0 set to 2 integration points PROPT Printout option EQ 1 0 average resultants and fiber lengths EQ 2 0 resultants at plan points and fiber lengths EQ 3 0 resultants stresses at all points fiber lengths LS DYNA Version 960 23 25 SEC
49. is available for modeling the expansion of explosive gases The reference geometry option is extended for foam and rubber materials and can be used for stress initialization see INITIAL_FOAM_REFERENCE GEOMETRY A vehicle positioning option is available for setting the initial orientation and velocities see INITIAL_VEHICLE_KINEMATICS A boundary element method is available for incompressible fluid dynamics problems The thermal materials work with instantaneous coefficients of thermal expansion MAT_ELASTIC_PLASTIC_THERMAL MAT_ORTHOTROPIC_THERMAL MAT_TEMPERATURE_DEPENDENT_ORTHOTROPIC MAT_ELASTIC_WITH_VISCOSITY Airbag interaction flow rate versus pressure differences Contact segment search option bricks first optional A through thickness Gauss integration rule with 1 10 points is available for shell elements Previously 5 were available Shell element formulations can be changed in a full deck restart The tied interface which is based on constraint equations TIED_SURFACE_TO_ SURFACE can now fail if _FAILURE is appended A general failure criteria for solid elements is independent of the material type see MAT_ADD_EROSION Load curve control can be based on thinning and a flow limit diagram see DEFINE_ CURVE_FEEDBACK An option to filter the spotweld resultant forces prior to checking for failure has been added the the option CONSTRAINED_SPOTWELD by appending _FILTERED_ FORCE to the keyword Bulk viscosity is
50. side ats 1 0 Location of reference surface normal to t axis for Hughes Liu beam elements only EQ 1 0 side at t 1 0 EQ 0 0 center EQ 1 0 side at t 1 0 Cross sectional area The definition on ELEMENT BEAM THICKNESS overrides the value defined here see Figure 23 1 Ij The definition on ELEMENT BEAM THICKNESS overrides the value defined here see Figure 23 1 Ig The definition on ELEMENT BEAM THICKNESS overrides the value defined here see Figure 23 1 Ij J polar inertia The definition on ELEMENT BEAM THICKNESS overrides the value defined here see Figure 23 1 If IRR is zero then IRR is reset to the sum of ISS ITT as an approximation Shear area The definition on ELEMENT BEAM THICKNESS overrides the value defined here see Figure 23 1 Volume of discrete beam If the mass density of the material model for the discrete beam is set to unity the magnitude of the lumped mass can be defined here instead This lumped mass is partitioned to the two nodes of the beam element The translational time step size for the type 6 beam is dependent on the volume mass density and the translational stiffness values so it is important to define this parameter Defining the volume is also essential for mass scaling if the type 6 beam controls the time step size LS DYNA Version 960 SECTION VARIABLE DESCRIPTION INER Mass moment of inertia for the six degree of freedom discrete beam This lumped inerti
51. version included a cost effective resultant beam element truss element a C triangular shell the BCIZ triangular shell Bazeley et al 1965 mixing of element formulations in calculations composite failure modeling for solids noniterative plane stress plasticity contact surfaces with spot welds tie break sliding surfaces beam surface contact finite stonewalls stonewall reaction forces energy calculations for all elements a crushable foam constitutive model comment cards in the input and one dimensional slidelines By the end of 1988 it was obvious that a much more concentrated effort would be required in the development of this software if problems in crashworthiness were to be properly solved therefore Livermore Software Technology Corporation was founded to continue the development of DYNA3D as a commercial version called LS DYNA3D which was later shortened to LS DYNA The 1989 release introduced many enhanced capabilities including a one way treatment of slide surfaces with voids and friction cross sectional forces for structural elements an optional user specified minimum time step size for shell elements using elastic and elastoplastic material models nodal accelerations in the time history database a compressible Mooney Rivlin material model a closed form update shell plasticity model a general rubber material model unique penalty specifications for each slide surface external work tracking optional time step criterion for
52. which contains the transformed data The data in this file can be used in future include files and should be checked to ensure that all the data was transformed correctly TRANID Transformation ID if 0 no tranformation will be applied See the input DEFINE_TRANSFORM Remarks To make the input file easy to maintain this keyword allows the input file to be split into subfiles Each subfile can again be split into sub subfiles and so on This option is beneficial when the input data deck is very large Consider the following example TITLE full car model INCLUDE carfront k INCLUDE carback k INCLUDE occupantcompartment k INCLUDE 15 4 INCLUDE LS DYNA Version 960 INCLUDE dummy k INCLUDE bag k CONTACT END Note that the command END terminates the include file The carfront k file can again be subdivided into rightrail k leftrail k battery k wheel house k shotgun k etc Each k file can include nodes elements boundary conditions initial conditions and so on INCLUDE rightrail k INCLUDE leftrail k INCLUDE battery k INCLUDE wheelhouse k INCLUDE shotgun k END The TRANSFORM option should be used cautiously and the transformed quantities should be checked closely for correctness LS DYNA Version 960 15 5 INCLUDE INCLUDE 15 6 INCLUDE LS DYNA Version 960 INITIAL INITIAL The keyword INITIAL provides a way of initializing velocities and detonation points
53. will be excluded BOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes bl b2 will be included DBOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes b1 b2 previously added will be excluded LS DYNA Version 960 24 21 SET SET Remarks 1 Shell attributes be assigned for some input types For example for the contact options the attributes for the SLAVE surface are DA1 NFLS Normal failure stress SURFACE contact only DA2 SFLS Shear failure stress CONTACT_TIEBREAK_ SURFACE contact only DA3 FSF Coulomb friction scale factor DA4 VSF Viscous friction scale factor and the attributes for the MASTER surface are DAI FSF Coulomb friction scale factor DA2 VSF Viscous friction scale factor Js The default attributes are taken The default shell attributes can overridden on these cards otherwise Al DAl etc 24 22 SET LS DYNA Version 960 SET SET SOLID OPTION Available options include BLANK GENERATE GENERAL The last option GENERATE will generate a block of solid element ID s between a starting ID and an ending ID An arbitrary number of blocks can be specified to define the set Purpose Define a set of solid elements Card Format 1 2 3 4 5 6 7 8 pee tee fe dd Cards 2 3 4 OPTION none The next card terminates the input 1 2 3 4 5 6 7 8 LS DYNA Version 960 24 23 SET SET
54. 0 2 0 1 0 SET NODE LIST 5 sid 21 5 1 nid2 32 33 SET NODE LIST 23 34 35 SET NODE LIST 25 36 37 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 5 13 CONSTRAINED CONSTRAINED Additional Cards 1 NPR required for the CROSS FILLET option Card 2 1 2 3 4 5 6 7 8 Cards 3 4 2 NPR VARIABLE DESCRIPTION TFAIL Failure time for constraint set default 1 E 20 EPSF Effective plastic strain at failure defines ductile failure SIGY Of stress at failure for brittle failure BETA failure parameter for brittle failure L L length of fillet butt weld see Figure 5 2 and 5 3 W w width of flange see Figure 5 2 A a width of fillet weld see Figure 5 2 ALPHA weld angle see Figure 5 2 in degrees NODEA Node ID A in weld pair CROSS or COMBINED option only See Figure 5 4 NODEB Node ID B in weld pair CROSS orCOMBINED option only NCID Local coordinate system ID CROSS or COMBINED option only 5 14 CONSTRAINED LS DYNA Version 960 CONSTRAINED Figure 5 4 A simple cross fillet weld illustrates the required input Here NFW 3 with nodal pairs A22 1 A23 B 1 and A 3 B 2 The local coordinate axes are shown These axes are fixed in the rigid body and are referenced to the local rigid body coordinate system which tracks the rigid body rotation LS DYNA Version 960 5 15 CONSTRAINED CONSTRAINE
55. 1 LOAD_THERMAL_CONSTANT_NODE Thermal load type 1 LOAD_THERMAL_LOAD_CURVE Thermal load type 2 LOAD THERMAL TOPAZ Thermal load type 3 LOAD_THERMAL VARIABLE Thermal load type 4 LOAD_THERMAL_VARIABLE NODE Thermal load type 4 LS DYNA Version 960 19 35 LOAD LOAD LOAD_THERMAL_CONSTANT Purpose Define nodal sets giving the temperature that remains constant for the duration of the calculation The reference temperature state is assumed to be a null state with this option A nodal temperature state read in above and held constant throughout the analysis dynamically loads the structure Thus the temperature defined can also be seen as a relative temperature to a surrounding or initial temperature Card Format Card 1 1 2 3 4 5 6 Jh 8 VARIABLE DESCRIPTION NSID Nodal set ID containing nodes for initial temperature see SET_NODES 0 all nodes are included NSIDEX Nodal set ID containing nodes that are exempted from the imposed temperature optional BOXID All nodes in box which belong to NSID are initialized Others are excluded optional T Temperature TE Temperature of exempted nodes optional 19 36 LOAD LS DYNA Version 960 LOAD LOAD_THERMAL_CONSTANT_NODE Purpose Define nodal temperature that remains constant for the duration of the calculation The reference temperature state is assumed to be a null state with this option A nodal temperature state read in above and h
56. 1 45 123456 LS DYNA Version 960 5 21 CONSTRAINED CONSTRAINED 5 inid idof twghtx twghty twohtz rwghtx rwghty rwghtz 22 123 44 123 43 123 Fenn aoe vt d 55555555555555555555555555555555555555555555555555555555555555555555555555555955 5 5856 OONSTRAINED INTERPOLATION Load redistribution 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Moment about normal axis of node 100 is converted to an equivalent load by 6 applying x force resultants to the nodes lying along the right boundary DEFINE CURVE 1 0 0 0 0 0 0 0 0 1 10000 LOAD NODE POINT 100 6 1 1 0 5 22 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED INTERPOLATION DBIS SI ie De Da Da SA ins eA AOR Se 5 dnid ddof 100 5 5 inid idof twghtx twghty twghtz rwghtx rwghty rwghtz 96 1 97 1 98 1 99 1 177 1 178 1 179 1 180 1 Mie ck OFS alg eek 180 173 176 177 100 98 LS DYNA Version 960 5 23 CONSTRAINED CONSTRAINED CONSTRAINED JOINT OPTION Available forms include one is mandatory CONSTRAINED JOINT SPHERICAL CONSTRAINED JOINT REVOLUTE CONSTRAINED JOINT CYLINDRICAL CONSTRAINED JOINT PLANAR CONSTRAINED JOINT UNIVERSAL CONSTRAINED JOINT TRANSLATIONAL CONSTRAINED JOINT LOCKING CONSTRAINED JOI
57. 1 9 AIRBAG AIRBAG Additional card required for ADIABATIC_GAS MODEL option 1 2 3 4 5 6 7 8 me fete EEE EEE EZ f Bi Mili Mili EN VARIABLE DESCRIPTION PSF Pressure scale factor LCID Optional load curve for preload flag See DEFINE_CURVE GAMMA Ratio of specific heats PO Initial pressure gauge PE Ambient pressure RO Initial density of gas Remarks The optional load curve ID LCID defines a preload flag During the preload phase the function value of the load curve versus time is zero and the pressure in the control volume is given as p PSF When the first nonzero function value is encountered the preload phase stops and the ideal gas law applies for the rest of the analysis If LCID is zero no preload is performed The gamma law equation of state for the adiabatic expansion of an ideal gas is used to determine the pressure after preload where p is the pressure p is the density e is the specific internal energy of the gas and y is the ratio of the specific heats 1 10 AIRBAG LS DYNA Version 960 AIRBAG The pressure above is the absolute pressure the resultant pressure acting on the control volume is p PSF p p where PSF is the pressure scale factor Starting from the initial pressure p an initial internal energy is calculated Po t p p y 1 LS DYNA Version 960 1 11 AIRBAG AIRBAG Additional 4 cards are required for all WANG_NEFSKE models C
58. 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NRBF Flag to delete or activate nodal rigid bodies If nodal rigid bodies or generalized weld definitions are active in the deformable bodies that are switched to rigid then the definitions should be deleted to avoid instabilities EQ 0 no change EQ 1 delete EQ 2 activate NCSF Flag to delete or activate nodal constraint set If nodal constraint spotweld definitions are active in the deformable bodies that are switched to rigid then the definitions should be deleted to avoid instabilities EQ 0 no change EQ 1 delete EQ 2 activate RWF Flag to delete or activate rigid walls 0 no change EQ 1 delete EQ 2 activate DTMAX Maximum permitted time step size after restart LS DYNA Version 960 29 29 RESTART RESTART For the D2R option define the following card Termination of this input is when the next card is read Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of the part which is switched to a rigid material MRB Part ID of the master rigid body to which the part is merged If zero the part becomes either an independent or master rigid body For the R2D option define the following card Termination of this input is when the next card is read Card Format DESCRIPTION VARIABLE PID Part ID of the part which is switched to a deformable material 29 30 RESTART LS DYNA Version 960 RESTART STRESS INIT
59. 2 3 4 5 6 7 8 Default VARIABLE DESCRIPTION NELEM Element number to which a wake is attached NSIDE The side of NELEM to which the wake is attached see Fig 3 2 This should be the downstream side of NELEM Remarks 1 Normally two elements meet at a trailing edge one on the upper surface and one on the lower surface The wake can be attached to either element but not to both 3 18 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY FLUX OPTION Available options are SEGMENT SET Purpose Define flux boundary conditions for a thermal or coupled thermal structural analysis Two cards are defined for each option For the SET option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 mE i UT di polo LS DYNA Version 960 3 19 BOUNDARY BOUNDARY Define the following card for both options Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT N1 N2 Node ID s defining segment LCID Load curve ID for heat flux see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier values at nodes LT 0 function versus temperature MLCI Curve multiplier at node N1 see Figure 3 2 MLC2 Curve multiplier at node N2 see Figure 3 2 MLC3 Curve multiplier at
60. 3 AFAC BFAC CFAC DFAC EFAC START ger AAFAC VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique ELFORM Element formulation options see Remarks 1 and 2 below EQ 1 Hughes Liu EQ 2 Belytschko Tsay EQ 3 BCIZ triangular shell EQ 4 Co triangular shell EQ 5 Belytschko Tsay membrane EQ 6 S R Hughes Liu EQ 7 S R co rotational Hughes Liu EQ 8 Belytschko Leviathan shell EQ 9 Fully integrated Belytschko Tsay membrane EQ 10 Belytschko Wong Chiang EQ 11 Fast co rotational Hughes Liu EQ 12 Plane stress x y plane EQ 13 Plane strain x y plane EQ 14 Axisymmetric solid y axis of symmetry area weighted EQ 15 Axisymmetric solid y axis of symmetry volume weighted EQ 16 Fully integrated shell element very fast EQ 17 Fully integrated DKT triangular shell element EQ 18 Fully integrated linear DK quadrilateral triangular shell EQ 20 Fully integrated linear assumed strain CO shell See remarks EQ 31 1 point Eulerian Navier Stokes EQ 32 8 point Eulerian Navier Stokes LS DYNA Version 960 23 13 SECTION SECTION VARIABLE SHRF NIP PROPT 23 14 SECTION DESCRIPTION The type 18 element is only for linear static and normal modes It can also be used for linear springback in sheet metal stamping Note that the 2D and 3D element types must not be mixed and different types of 2D elements must not be used together
61. 3 NODE NODE_RIGID_SURFACE Purpose Define a rigid node and its coordinates in the global coordinate system These nodes are used to define rigid road surfaces and they have no degrees of freedom The nodal points are used in the definition of the segments that define the rigid surface See CONTACT_RIGID_SURFACE Card Format 18 3 16 0 Card 1 1 2 3 4 3 6 7 8 9 10 I I To TIP mf fe VARIABLE DESCRIPTION NID Node number X X coordinate Y y coordinate Z Z coordinate 20 4 NODE LS DYNA Version 960 PART PART Three keywords are used in this section PART_ OPTION1 _ OPTION2 _ OPTION3 _ OPTION4 PART_MODES PART_MOVE LS DYNA Version 960 21 1 PART PART PART OPTIONI OPTION2 OPTION3 _ OPTION4 For OPTIONI the available choices are BLANK INERTIA REPOSITION For OPTION2 the available choices are BLANK CONTACT For OPTIONS the available choices are BLANK PRINT For OPTION4 the available choices are BLANK ATTACHMENT NODES Options 1 2 3 and 4 may be specified in any order on the PART card Purpose Define parts i e combine material information section properties hourglass type thermal properties and a flag for part adaptivity The INERTIA option allows the inertial properties and initial conditions to be defined rather than calculated from the finite element mesh This applies to rigid bodies see MAT RIG
62. 3 4 5 6 7 8 VARIABLE DESCRIPTION IFORM Output format for D3PLOT and D3THDT files EQ 0 LS DYNA database format default EQ 1 ANSYS database format EQ 2 Both LS DYNA and ANSYS database formats IBINARY Word size of the binary output files D3PLOT D3THDT D3DRLF and interface files for 64 bit computer such as CRAY and NEC EQ 0 default 64 bit format EQ 1 32 bit IEEE format Remarks 1 This option is not available for every platform Check LS DYNA Banner upon execution of the program 2 By using this option one can reduce the size of the binary output files which are created by 64 bits computer such as CRAY and NEC LS DYNA Version 960 9 21 DATABASE DATABASE DATABASE HISTORY OPTION Options include BEAM BEAM SET NODE NODE LOCAL NODE SET NODE SET LOCAL SHELL SHELL SET SOLID SOLID SET SPH SPH SET TSHELL TSHELL SET Purpose Control which nodes or elements are output into the binary history file D3THDT the ASCII file NODOUT the ASCII file ELOUT and the ASCII file SPHOUT Define as many cards as necessary The next card terminates the input See also DATABASE BINARY OPTION and DATABASE OPTION Card Format for all options except NODE_LOCAL and NODE_SET_LOCAL Cards 1 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IDn NODE NODE_SET or element element set ID n Elements may be BEAM BEAM_SET SHELL SHELL_SET SOLID SOLID_SET or TSHELL TSHELL_SET
63. 4 node shell elements and internal element sorting to allow full vectorization of right hand side force assembly During the last ten years considerable progress has been made as may be seen in the chronology of the developments which follows added in 1989 1990 arbitrary node and element numbers fabric model for seat belts and airbags composite glass model vectorized type 3 contact and single surface contact many more I O options all shell materials available for 8 node thick shell strain rate dependent plasticity for beams fully vectorized iterative plasticity interactive graphics on some computers nodal damping shell thickness taken into account in shell type 3 contact shell thinning accounted for in type 3 and type 4 contact soft stonewalls print suppression option for node and element data massless truss elements rivets based on equations of rigid body dynamics massless beam elements spot welds based on equations of rigid body dynamics expanded databases with more history variables and integration points force limited resultant beam rotational spring and dampers local coordinate systems for discrete elements resultant plasticity for triangular element energy dissipation calculations for stonewalls hourglass energy calculations for solid and shell elements viscous and Coulomb friction with arbitrary variation over surface distributed loads on beam elements Cowper and
64. 7 8 VARIABLE DESCRIPTION RMIN Minimum edge length for the surface mesh surrounding the parts which should be remeshed RMAX Maximum edge length for the surface mesh surrounding the parts which should be remeshed Remarks 1 The value of RMIN and RMAX should be of the same order The value of RMAX can be set to 2 5 times greater than RMIN 7 64 CONTROL LS DYNA Version 960 CONTROL CONTROL_RIGID Purpose Special control options related to rigid bodies and the rigid flexible bodies see PART MODES Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LMF Switch the explicit rigid body joint treatment to an implicit formulation which uses Lagrange multipliers to impose prescribed kinematic boundary conditions and joint constraints This is a new option which is underdevelopment in version 960 There is a slight cost overhead due to the assembly of sparse matrix equations which are solved using standard procedures for nonlinear problems in rigid multi body dynamics Lagrange multiplier flag EQ 0 explicit penalty formulation EQ 1 implicit formulation with Lagrange multipliers LMF Generalized joint stiffness formulation see remark 1 below EQ 0 incremental update EQ 1 total formulation exact ORTHMD Orthogonalize modes with respect to each other 0 true EQ 1 false the modes are already orthogonalized PARTM Use global mass matrix to determine part mass distribution This mass matrix m
65. 84 apply motion to part number 84 5 dof 7 rotation is prescribed about the z axis 5 2 the prescribed motion is displacement angular 5 lcid 9 rotation follows load curve 9 requires a DEFINE CURVE 5 rotation should be radians 5 sf use default sf 1 0 vid not used in this example 3 34 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY PRESSURE CFD SET Purpose Apply a pressure load over each segment in a segment set for the incompressible flow solver The pressure convention follows Figure 3 8 Card Format Card 1 1 2 3 4 5 6 7 8 Default VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT LCID Load curve ID see DEFINE CURVE P Pressure to be applied Remarks 1 The load curve multipliers may be used to increase or decrease the pressure amplitude The time value is not scaled LS DYNA Version 960 3 35 BOUNDARY BOUNDARY b 3 Dimensional definition for pressure boundary segments Figure 3 8 Nodal numbering for pressure boundary segments Positive pressure acts in the negative t direction For two dimensional problems repeat the second node for the third and fourth nodes in the segment definitions 3 36 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY PRESSURE OUTFLOW OPTION Available options are SEGMENT SET Purpose Define pressure outflow boundary conditions These boundary conditions are attached to solid elements using the Eule
66. BOUNDARY LS DYNA Version 960 BOUNDARY Define the following card for both options Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT N1 N2 Node ID s defining segment HLCID Load curve ID for heat transfer coefficient h GT O function versus time EQ 0 use constant multiplier value HMULT LT 0 function versus temperature HMULT Curve multiplier for h TLCID Load curve ID for versus time see DEFINE CURVE EQ 0 use constant multiplier value TMULT TMULT Curve multiplier for Remarks A convection boundary condition is calculated using 4 h T Too where h heat transfer coefficient T Too temperature potential Three alternatives are possible for the heat transfer coefficient which can be a function of time a function of temperature or constant Also the temperature of the boundary Too can be either constant or a function of time For both curves multipliers can be used to scale the values LS DYNA Version 960 3 5 BOUNDARY BOUNDARY BOUNDARY CYCLIC Purpose Define nodes in boundary planes for cyclic symmetry These boundary conditions can be used to model a segment of an object that has rotational symmetry such as an impeller i e Figure 3 1 The segment boundary denoted as a side 1 and side 2 may be curved or planar In this section a paired list of points are defined on the sides that are to be joined Card
67. Batch execution in some installations e g GM is controlled by file NAMES on unit 88 NAMES is a 2 line file in which the second line is blank The first line of NAMES contains the execution line I inf if this is the initial run For a restart the execution line becomes I inf R rtf Remark No stress initialization is possible at restart Also the VDA files and the CAL3D files cannot be changed 1 30 INTRODUCTION LS DYNA Version 960 INTRODUCTION RESTART ANALYSIS The LS DYNA restart capability allows analyses to be broken down into stages After the completion of each stage in the calculation a restart dump is written that contains all information necessary to continue the analysis The size of this dump file is roughly the same size as the memory required for the calculation Results can be checked at each stage by post processing the output databases in the normal way so the chance of wasting computer time on incorrect analyses is reduced The restart capability is frequently used to modify models by deleting excessively distorted elements materials that are no longer important and contact surfaces that are no longer needed Output frequencies of the various databases can also be altered Often these simple modifications permit the calculation to continue on to a successful completion Restarting can also help to diagnose why a model is giving problems By restarting from a dump that is written before the occurrence of
68. DYNA Version 960 7 43 CONTROL CONTROL N Time Step Size Limit E o Figure 7 2 Remarks IAUTO ITEOPT ITEWIN DTMAX DTMAX active from previous key point to current key point A key point is automatically generated at the termination time Problem Time t negative key point no plot state Q user defined key point LS DYNA generated key point A key point load curve can be identified with a negative value for DTMAX Function values of each load curve point give DTMAX Time values are reached exactly by the automatic step controller and a plot state is output unless DTMAX is negative The default for IAUTO depends on the analysis type For springback analysis automatic time step control and artificial stabilization are activated by default The time step size is adjusted so that equilibrium is reached in ITEOPT iterations increasing after easy steps and decreasing after difficult but successful steps A value of ITEOPT 21 or more can be more efficient for highly nonlinear simulations by allowing more iterations in each step hence fewer total steps The step size is not adjusted if the iteration count falls within ITEWIN of ITEOPT Large values of ITEWIN make the controller more tolerant of variations in iteration count To strike a particular simulation time exactly use a key point load curve Figure 7 2 an
69. EOS Card Format Card 1 1 2 3 4 5 6 VARIABLE DESCRIPTION EOSID Equation of state label CO Cl C2 C3 C4 C5 C6 EO Initial internal energy vo Initial relative volume 13 2 EOS LS DYNA Version 960 EOS Remarks The linear polynomial equation of state is linear in internal energy The pressure is given by where terms Cou2 and Con are set to zero if u lt 0 u Be 1 and 6 is the ratio of current 0 p 0 density to initial density The linear polynomial equation of state may be used to model gas with the gamma law equation of state This may be achieved by setting G G C 0 and C CG y 1 where y is the ratio of specific heats The pressure is then given by The units of E are the units of pressure LS DYNA Version 960 13 3 EOS EOS EOS JWL This is Equation of state Form 2 Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION EOSID Equation of state label A B R2 OMEG EO vo Initial relative volume Remarks The JWL equation of state defines the pressure as p A ee Qu R V R V V 1 2 and is usually used for detonation products of high explosives 13 4 EOS LS DYNA Version 960 EOS EOS_SACK_TUESDAY This is Equation of state Form 3 Card Format VARIABLE DESCRIPTION EOSID Equation of state label Al A2 A3 Bl B2 EO Initial internal energy vo Initial relative volume
70. EQ 0 Allow initial penetrations to remain EQ 1 Push apart initially penetrated surfaces Closing Opening flag for implicit analysis EQ 0 Recommended for most problem where gaps are only closing EQ 1 Recommended when gaps are opening to aviod sticking Special processing during initializaion EQ 0 No special processing EQ 1 Forming option Thermal conductivity k of fluid between the slide surfaces If a gap with thickness exists between the slide surfaces then the conductance due to thermal conductivity between the slide surfaces is _ cond gap Note that LS DYNA calculates based on deformation Radiation factor f between the slide surfaces A radient heat transfer coefficient is calculated see BOUNDARY_RADIATION If a gap exists between the slide surfaces then the contact conductance is calculated by h h cond h rad Heat transfer conductance h for closed gaps Use this heat transfer conductance for gaps in the range 0 lt lt Ln where is GCRIT defined below Critical gap 1 use the heat transfer conductance defined HTC for gap thicknesses less than this value No thermal contact if gap is greater than this value Za 6 61 CONTACT CONTACT CD_FACT Is a multiplier used on the element characteristic distance for the search routine The characteristic length is the largest interface surface element diagonal EQ 0 Default set to 1 0 Remar
71. EQ 2 On with slip condition This option used for ALE and EULER formulations defines velocity boundary conditions for the user Velocity boundary conditions are applied to all nodes on free surfaces of an ALE or Eulerian material For problems where the normal velocity of the material at the boundary is zero such as injection molding problems the automatic boundary condition parameter is set to 2 This will play the same role as the Nodal Single Point Constraint For EBC 1 the material velocity of all free surface nodes of ALE and Euler material is set to zero 7 11 CONTROL CONTROL CONTROL_BULK_VISCOSITY Purpose Reset the default values of the bulk viscosity coefficients globally This may be advisable for shock wave propagation and some materials Bulk viscosity is used to treat shock waves A viscous term q is added to the pressure to smear the shock discontinuities into rapidly varying but continuous transition regions With this method the solution is unperturbed away from a shock the Hugoniot jump conditions remain valid across the shock transition and shocks are treated automatically Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION 01 Default quadratic viscosity coefficient Q2 Default linear viscosity coefficient TYPE Default bulk viscosity type IBQ Default 1 1 standard also type 2 10 and 16 shell elements EQ 1 standard Remarks The bulk viscosity creates an additional additive pressure t
72. F2fmxig the growth rate is set equal to zero when F gt fmxgr and the completion rate is set equal to zero when F lt fmner Details of the computational methods and many examples of one and two dimensional shock initiation and detonation wave calculation can be found in the references Unfortunately sufficient experimental data has been obtained for only two solid explosives to develop very reliable shock initiation models PBX 9504 and the related HMX based explosives LX 14 LX 10 LX 04 etc and LX 17 the insensitive TATB based explosive Reactive flow models have been developed for other explosives TNT PETN Composition B propellants etc but are based on very limited experimental data 13 16 EOS LS DYNA Version 960 EOS History variables 85 and 89 are temperature and burn fraction respectively See DATABASE EXTENT BINARY if these output variables are desired in the databases for post processing LS DYNA Version 960 13 17 EOS EOS EOS TABULATED COMPACTION Card Format Card 1 1 2 3 4 5 6 7 8 Card Format 5E16 0 Card 2 1 2 3 4 5 Card 3 Repeat Cards 2 and 3 for and A total of 9 cards must be defined VARIABLE DESCRIPTION EOSID Equation of state label eV1 eV2 eVN In V C1 C2 CN T1 T2 TN K1 K2 KN GAMA y EO Initial internal energy Initial relative volume 13 18 EOS LS DYNA Version 960 EOS Remarks The tabulated compaction model is linear in inter
73. ILIMIT MAXREF Arc length controlling node ID EQ 0 generalized arc length method Arc length controlling node direction ignored if ARCCTL 0 above EQ 1 global X translation EQ 2 global Y translation EQ 3 global Z translation Relative arc length size See remarks below LE 0 0 use automatic size size GT 0 0 use ARCLEN automatic step size Arc length method EQ 1 Crisfield default EQ 2 Ramm Arc length damping option EQ 2 off default EQ 1 on oscillations in static solution are supressed This flag may be used to select a linear springback analysis This disables equilibrium checking and iterations The default nonlinear BFGS method can be used as a Full Newton method by resetting the ILIMIT parameter below In the neighborhood of limit points the Newton based iteration schemes often fail The arc length method of Riks and Wempner combined here with the BFGS method adds a constraint equaiton to limit the load step to a constatnt arc Length in load displacement space This latter method is frequently used to solve snap through buckling problems When applying the arc length method the load curves that define the loading should contain two points and start at the origin 0 0 If the arc length method is flagged and if two points characterize the load curve LS DYNA will extrapolate if necessary to determine the load Time and load magnitude are related by a constant when the arc length method is used and it is
74. INITIAL_FOAM_REFERENCE_GEOMETRY Purpose The reference configuration allows stresses to be initialized in the material model MAT_LOW_DENSITY_FOAM To use this option the geometry of the foam material is defined in a deformed configuration The stresses in the low density foam then depend only on the deformation gradient matrix 1 F ax where X is the undeformed configuration By using this option dynamic relaxation can be avoided once a deformed configuration is obtained usually on the first run of a particular problem Card Format 18 3E16 0 s VARIABLE DESCRIPTION NID Node number X x coordinate Y y coordinate Z z coordinate LS DYNA Version 960 16 7 INITIAL INITIAL INITIAL_MOMENTUM Purpose Define initial momentum to be deposited in solid elements This option is to crudely simulate an impulsive type of loading Card Format 1 2 3 foe foo VARIABLE DESCRIPTION EID Element ID MX Initial x momentum MY Initial y momentum MZ Initial z momentum DEPT Deposition time 16 8 INITIAL LS DYNA Version 960 INITIAL INITIAL STRAIN SHELL Purpose Initialize strain tensor and inner and outer through thickness integration points at element center This option is primarily for multi stage metal forming operations where the accumulated strain is of interest Define as many shell elements in this section as desired The input is assumed to terminate when a new keyword is det
75. LS DYNA Version 960 18 5 INTERFACE INTERFACE INTERFACE_SPRINGBACK_OPTIONI_OPTION2 Options included for OPTION are NIKE3D DYNA3D NASTRAN SEAMLESS and for OPTION2 THICKNESS NOTHICKNESS See the remarks below Purpose Define a material subset for an implicit springback calculation in LS NIKE3D and any nodal constraints to eliminate rigid body degrees of freedom Card Format VARIABLE DESCRIPTION PSID Part set ID for springback see SET_PART 18 6 INTERFACE LS DYNA Version 960 INTERFACE Define a list of nodal points that are constrained for the springback This section is terminated by an 6699 indicating the next input section Card Format VARIABLE DESCRIPTION NID Node ID see NODE TC Tranlational Constraint 0 no constraints EQ 1 constrained x displacement EQ 2 constrained y displacement EQ 3 constrained z displacement EQ 4 constrained x and y displacements EQ 5 constrained y and z displacements EQ 6 constrained z and x displacements EQ 7 constrained x y and z displacements RC Rotational constraint 0 no constraints EQ 1 constrained x rotation EQ 2 constrained y rotation EQ 3 constrained z rotation EQ 4 constrained x and y rotations EQ 5 constrained y and z rotations EQ 6 constrained z and x rotations EQ 7 constrained x y and z rotations LS DYNA Version 960 18 7 INTERFACE INTERFACE Remarks 1 The default is NIKE3D w
76. LS DYNA Version 960 7 17 CONTROL CONTROL VARIABLE IADVEC IFCT DIVU THETAK THETAA THETAF MSOL MAXIT ICHKIT IWRT IHIST 7 18 CONTROL DESCRIPTION Toggle the treatment of advection between explicit with balancing tensor diffusivity BTD or fully implicit EQ 0 IADVEC 10 for forward Euler with BTD default EQ 1 IADVEC 0 for foward Euler without BTD EQ 10 forward Euler with BTD EQ 40 fully implicit with simplified trapezoid rule Toggle the use of the advective flux limiting advection scheme EQ 0 IFCT 1 default EQ 1 Advective flux limiting is on EQ 1 Advective flux limiting is off Set the RMS divergence tolerance i e V ul aus lt E This tolerance is used for the initial startup procedure to insure that proper initial conditions are prescribed for the momentum equations EQ 0 DIVU 1 0e 5 default Time weighting for viscous diffusion terms Valid values are 0 0 lt 1 with for second order accuracy in time EQ 0 THETAK O 5 default Time weighting for advection terms Time weighting for body forces and boundary conditions Valid values are 0x0 lt 1 with for second order accuracy in time EQ 0 THETAF 0 5 default Set the equation solver type for the momentum equations EQ 0 MSOL 20 default EQ 20 Jacobi preconditioned conjugate gradient method EQ 30 Jacobi preconditioned conjugate gradient squared method defau
77. LS DYNA Version 960 7 7 CONTROL CONTROL VARIABLE ADPENE ADPTH MEMORY ORIENT MAXEL Remarks DESCRIPTION Adapt the mesh when the contact surfaces approach or penetrate the tooling surface depending on whether the value of ADPENE is positive approach or negative penetrates respectively The tooling adaptive refinement is based on the curvature of the tooling If ADPENE is positive the refinement generally occurs before contact takes place consequently it is possible that the parameter ADPASS can be set to 1 in invoke the one pass adaptivity Absolute shell thickness level below which adaptive remeshing should began If zero this parameter is ignored This option works only if ADPTOL is nonzero If thickness based adaptive remeshing is desired without angle changes then set ADPTOL to a large angle This flag can have two meanings depending on whether the memory environmental variable is or is not set The command setenv LSTC_MEMORY auto sets the memory environmental variable which causes LS DYNA to expand memory automatically Note that automatic memory expension is not always 100 reliable depending on the machine and operating system level consequently it is not yet the default To see if this is set on a particular machine type the command env If the environmental variable is not set then when memory usage reaches this percentage MEMORY further adaptivity is prevented to avoid exceeding the me
78. MAT areas anne et eR OE eene Hi 434 MAT CPDEZOPBLBON cet toc ee SERIE shes RET ee hash ews 436 MAT THERMAL OPTION eise RH btt RR RA ORE deep 438 REFERENCES ee IND AREE ERE ae ns ERE nes REF 1 APPENDIX A USER DEFINED MATERIALS 2 0er APPENDIX USER DEFINED AIRBAG SENSOR B 1 APPENDIX C USER DEFINED SOLUTION CONTPROL 4 mmm C 1 APPENDIX D USER DEFINED INTERFACE CONTROL III III D 1 APPENDIX E USER DEFINED INTERFACE E 1 APPENDIX F OCCUPANT SIMULATION INCLUDING COUPLING TO CAL3D AND MADYMO F 1 INTRODUCTION EE F 1 THE LS DYNA OCCUPANT SIMULATION PROGRAM 1 DUMMY MODELING ege tea e tert RER E e ER F 3 LS DYNA Version 960 xiii TABLE OF CONTENTS AIRBAG MODELING irii pee ER RE REPE EAR RA DE FERE ER LEN I etg F 3 KNEE BOLSTER oe Rene AES F 4 COMMON ERRORS intet er Ye EIS seed a seas cd eda ee ede aka F 5 APPENDIX G INTERACTIVE GRAPHICS 5 G 1 APPENDIX H INTERACTIVE MATERIAL MODEL H 1 INTRODUCTION 8 oec a REDI eU EE edere H 1 INPUT DEFINITION ennei Hebe Ee Foto nme H 1 INTERACTIVE DRIVER 8 H 3 APPENDIX I VDA D
79. MAT SOM CONCRBTE iin tse I ea Senne I deeb 228 MAT HYSTERETIC SOID zs 22222 mI 232 MAT RAMBERG OSGOOD 5 eret eer Ree ee Bas nei 235 MAT PLASTICITY WITH 8 237 MAT FU pete titi ette naeh ls ete 242 MAT WINFRITH CONCRETE rer Nus 249 MAT WINFRITH CONCRETE REINFORCEMEBENT eee 253 MAT_ORTHOTROPIC VISCOELASTIC a ee tod ee te Pede 255 MAT CELLULAR RUBBER gsi scsi ette eR t PEDIS 258 NUES En Er ONERE ERES EDO D EO 263 MAT PLASTIC POLYMER un un ee len 268 MAT ACOUSTIC are ete senda te et e POPE ev Fler owe een 270 5 en 272 MATUBRITILE DAMAGE ois eel ebenen 276 MAT SIMPLIFIED JOHNSON 9 279 MAT SPOTWEED OPTION are tends ae 281 LS DYNA Version 960 xi TABLE OF CONTENTS MAT GEPLASTIC SSRATE 2000a ertt Hr see ka 285 MAT INV HYPERBOLIC SIN 1 reete eee Ba 287 MAT ANISOTROPIC 289 DAMAGE 32 ee eee gas Seas aks ehe les HE eet oat ose 294 MAT DAMAGE eosdebet o a ak I OR NORD I RN ridet i 299 MAT ELASTIC VISCOPLASTIC 303 MAT JOHNSON HOLMQUIS
80. NODE LIST Ur Ur Ur TU Gk Ur UY UY Ur UY UY Ur UY UY UY Ur Ur UW UY Ur Ur Ur 4 UY Ur UY Ur UY X UY UY UY sid dal da2 da3 da4 2 nidi nid2 nid3 nid4 nid5 nid7 nid8 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 DEFINE CURVE lcid sidr scla sclo offa offo 3 5 DEPIH FORC LGTH 0 000E 00 0 000E 00 1 200E 01 1 300 02 1 500E 01 2 000E 02 1 800E 01 5 000 02 LS DYNA Version 960 6 37 CONTACT CONTACT CONTACT_ENTITY Purpose Define a contact entity Geometric contact entities treat the impact between a deformable body defined as a set of slave nodes or nodes in a shell part set and a rigid body The shape of the rigid body is determined by attaching geometric entities Contact is treated between these geometric entities and the slave nodes using a penalty formulation The penalty stiffness is optionally maximized within the constraint of the Courant criterion As an alternative a finite element mesh made with shells can be used as geometric entity Also axisymmetric entities with arbitrary shape made with multilinear polygons are possible The latter is particularly useful for metalforming simulations WARNING If the problem being simulated involves dynamic motion of the entity care should be taken to insure that the inertial properties of the entity are correct It may be necessary to use the PART_INERTIA option to specify these properties Define 5 cards for the contact entity definition
81. Note that the motion of the master rigid body is not directly affected by this option 1 no forces are generated on the master rigid body The activation time BIRTH is the time during the solution that the constraint begins to act Until this time the prescribed motion card is ignored The function value of the load curves will be evaluated at the offset time given by the difference of the solution time and BIRTH i e solution time BIRTH Relative displacements that occur prior to reaching BIRTH are ignored Only relative displacements that occur after BIRTH are prescribed When the constrained node is on a rigid body the translational motion is imposed without altering the angular velocity of the rigid body by calculating the appropriate translational velocity for the center of mass of the rigid body using the equation Von V cm node 70X Xem Ex Xnode where is the velocity of the center of mass v cm is the specified nodal velocity is the angular velocity of the rigid body x is the current coordinate of the mass center and x is the current coordinate of the nodal point Extreme care must be used when prescribing motion of a rigid body node cm LS DYNA Version 960 3 33 BOUNDARY BOUNDARY node Typically for nodes on a given rigid body the motion of no more than one node should be prescribed or unexpected results may be obtained 5 55555555555555555555555555555555555555555555555555555555
82. P of the body by b p x xr where p is the mass density is the angular velocity vector and r is a position vector from the origin to point P Although the angular velocity may vary with time the effects of angular acceleration are included Angular velocities are useful for studying transient deformation of spinning three dimensional objects Typical applications have included stress initialization during dynamic relaxation where the initial rotational velocities are assigned at the completion of the initialization and this option ceases to be active LS DYNA Version 960 19 11 LOAD LOAD LOAD_BRODE Purpose Define Brode function for application of pressure loads due to explosion see Brode 1970 also see LOAD_SEGMENT LOAD_SEGMENT_SET or LOAD_SHELL Card Format Card 1 1 2 3 4 5 6 7 8 el LIII Card 2 1 2 3 4 5 6 7 8 LLLI VARIABLE DESCRIPTION YLD Yield Kt equivalent tons of TNT BHT Height of burst XBO x coordinates of Brode origin YBO y coordinates of Brode origin ZBO Z coordinates of Brode origin TBO Time offset of Brode origin 19 12 LOAD LS DYNA Version 960 LOAD VARIABLE DESCRIPTION TALC Load curve number giving time of arrival versus range relative to Brode origin space time see DEFINE_CURVE and remark below SFLC Load curve number giving yield scaling versus scaled time time relative to Brode origin div
83. PA m This is different from the standard LS DYNA jetting formulation which assumes that the density of the gas in the jet is the same as atmospheric air and then calculates the jet velocity from conservation of mass flow 1 24 AIRBAG LS DYNA Version 960 AIRBAG The velocity distribution at any radius r from the jet centerline and distance z from the focus relates to the velocity of the jet centreline vr 0 z in the same way as the standard LS DYNA jetting options The velocity at the jet centerline vr 0 at the distance z from the focus of the jet is calulated such that the momentum in the jet is conserved Momentum at nozzle Momentum at z 2 m 2 PoV outer Aoutet m Po Vd zb Fb where 2 TO p 1 T F distance between jet focii for a passenger jet Finally the pressure exerted on an airbag element in view of the jey is given y Z 2 D 2 combining the eqations above 270 BMV e 7 2 er az 2 2 The total force exerted by the jet is given by F jet outlet independent of distance from the nozzle Mass flow in the jet is not necessarily conserved because gas is entrained into the jet from the surrounding volume By contrast the standard LS DYNA jetting formulation conserves mass flow but not momentum This has the effect of making the jet force reduce with distance from the nozzle The jetting forces can be reacted onto a
84. R2D 1 SD Zaren eed en Din Dan a ee MORE ode e Dreier B 5 swset code time 1 time 2 time 3 entno relsw paired 10 2 3 20 nrbf ncsf rwf dtmax D2R R2D LS DYNA Version 960 11 5 DEFORMABLE TO RIGID DEFORMABLE TO RIGID Define D2R cards below Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of the part which is switched to a rigid material MRB Part ID of the master rigid body to which the part is merged If zero the part becomes either an independent or master rigid body Define R2D cards below Card Format VARIABLE DESCRIPTION PID Part ID of the part which is switched to a deformable material 11 6 DEFORMABLE_TO_RIGID LS DYNA Version 960 DEFORMABLE TO RIGID DEFORMABLE TO RIGID INERTIA Purpose Inertial properties can be defined for the new rigid bodies that are created when the deformable parts are switched These can only be defined in the initial input if they are needed in a later restart Unless these properties are defined LS DYNA will recompute the new rigid body properties from the finite element mesh The latter requires an accurate mesh description When rigid bodies are merged to a master rigid body the inertial properties defined for the master rigid body apply to all members of the merged set Card Format Card 1 Card 2 ER UN NE 3 me Pelee te LS DYNA Version 960 11 7 DE
85. SET can lead to nonphysical responses 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 CONSTRAINED NODE SET 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 6 Constrain all the nodes nodal set to move equivalently in the z direction CONSTRAINED NODE SET etie he eese Decii ees Ree heh 28 nsid dof tf 7 3 10 0 5 nsid 7 nodal set ID number requires a SET NODE option 5 dof 3 nodal motions are equivalent in z translation 5 0 73 at time 10 the nodal contraint is removed 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 56 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED POINTS Purpose Constrain two points with the specified coordinates connecting two shell elements at locations other than nodal points In this option the penalty method is used to constrain the translational and rotational degrees of freedom of the points Force resultants are written into the SWFORC ASCII file for post processing Card Format I10 Card 1 1 Card Format 18 3E16 0 Card 2 1 2 3 4 5 6 7 8 9 10 Card 3 1 2 3 4 5 6 7 8 9 10 LS DYNA Version 960 5 57 CONSTRAINED CONSTRAINED Card Format 4E10 0 Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION CID Constrained points ID Xi Yi Zi Coordinates of the con
86. Symonds strain rate model segmented stonewalls stonewall Coulomb friction 1 2 INTRODUCTION LS DYNA Version 960 INTRODUCTION stonewall energy dissipation airbags 1990 nodal rigid bodies automatic sorting of triangular shells into groups mass scaling for quasi static analyses user defined subroutines warpage checks on shell elements thickness consideration in all contact types automatic orientation of contact segments sliding interface energy dissipation calculations nodal force and energy database for applied boundary conditions defined stonewall velocity with input energy calculations added in 1991 1992 rigid deformable material switching rigid bodies impacting rigid walls strain rate effects in metallic honeycomb model 26 shells and beams interfaces included for subsequent component analyses external work computed for prescribed displacement velocity accelerations linear constraint equations MPGS database MOVIE database Slideline interface file automated contact input for all input types automatic single surface contact without element orientation constraint technique for contact cut planes for resultant forces crushable cellular foams urethane foam model with hysteresis subcycling friction in the contact entities strains computed and written for the 8 node thick shells good 4 node tetrahedron solid element with nodal rotations 8 node solid element
87. THICKNESS option is provided for the user to override the SECTION BEAM data which is taken as the default if the THICKNESS option is not used End release conditions are imposed used constraint equations and caution must be used with this option as discussed in remark 2 below The PID option is used by the type 9 spot weld element only and is ignored for all other beam types When the PID option is active an additional card is read that gives two part ID s that are tied by the spot weld element If the PID option is inactive for the type 9 element the nodal points of the spot weld are located to the two nearest segments The surface of each segment should project to the other and in the most typical case the node defining the weld assuming only one node is used should lie in the middle however this is not a requirement Note that with the spotweld elements only one node is needed to define the weld and two nodes are optional Card Format 1018 1 2 3 4 5 6 7 8 9 10 12 2 ELEMENT LS DYNA Version 960 ELEMENT Optional Card Required if THICKNESS is specified after the keyword 1 2 3 4 5 6 7 8 9 10 PARMI PARM2 PARM3 PARMA 5 s ds hstisls Optional Card Required if PID is specified after the keyword 1 2 3 4 5 6 7 8 9 10 VARIABLE EID PID N1 N2 N3 LS DYNA Version 960 DESCRIPTION Element ID A unique number has to be specified Part ID see PART Nodal point end 1
88. The keyword control cards in this section are defined in alphabetical order INITIAL_CFD INITIAL_DETONATION INITIAL_FOAM_REFERENCE_GEOMETRY INITIAL_MOMENTUM INITIAL_STRAIN_SHELL INITIAL_STRESS_ BEAM INITIAL STRESS SHELL INITIAL STRESS SOLID INITIAL TEMPERATURE OPTION INITIAL VEHICLE KINEMATICS Two mutually exclusive methods are available for initial velocity generation INITIAL VELOCITY INITIAL VELOCITY NODE and INITIAL VELOCITY GENERATION The latter is convenient for specifying initial rotational velocities about arbitrary axes These method for velocity generation must not be mixed in a single input deck INITIAL VOID OPTION INITIAL VOLUME FRACTION LS DYNA Version 960 16 1 INITIAL INITIAL INITIAL_CFD Purpose Specify initial conditions for all nodal variables in the incompressible CFD solver Card Format 1 of 3 Card 1 3 4 5 6 7 8 II e oo oo Card Format 2 of 3 16 2 INITIAL LS DYNA Version 960 INITIAL Card Format 3 of 3 Card 3 1 2 3 4 5 6 7 8 DISDITIILILI feted llo VARIABLE DESCRIPTION U Initial x velocity V Initial y velocity W Initial z velocity T Initial temperature H Initial enthalpy RHO Initial density 71 Initial Species 1 concentration Z2 Initial Species 2 concentration Z10 Initial Species 10 concentration K Initial turbulent kinetic energy EPS Initial turbulent dissipation rate LS DYNA Version 960 16 3 INITIAL
89. This feature allows an initial tightening of the belt and takes up any slack whenever it occurs The tension value is taken from the first point on the force pullout load curve The maximum rate of pull out or pull in is given by 0 01 x fed length per time step Because of this the constant tension value is not always achieved LS DYNA Version 960 12 19 ELEMENT ELEMENT In the locked regime a user defined curve describes the relationship between the force in the attached element and the amount of belt material paid out If the tension in the belt subsequently relaxes a different user defined curve applies for unloading The unloading curve is followed until the minimum tension is reached The curves are defined in terms of initial length of belt For example if a belt is marked at 10mm intervals and then wound onto a retractor and the force required to make each mark emerge from the locked retractor is recorded the curves used for input would be as follows 0 Minimum tension should be gt zero 10mm Force to emergence of first mark 20mm Force to emergence of second mark Pyrotechnic pretensions may be defined which cause the retractor to pull in the belt at a predetermined rate This overrides the retractor force pullout relationship from the moment when the pretensioner activates If desired belt elements may be defined which are initially inside the retractor These will emerge as belt material is paid out and may r
90. This shape is useful for velocity control of tools in metal forming applications Card Format 1 2 3 4 5 6 7 8 LCID SIDR DIST TSTART TEND TRISE fe fete Default none none none none none none none LT DESCRIPTION VARIABLE LCID SIDR DIST TSTART TEND TRISE 10 16 DEFINE Load curve ID must be unique Stress initialization by dynamic relaxation EQ 0 load curve used in transient analysis only or for other applications EQ 1 load curve used in stress initialization but not transient analysis EQ 2 load curve applies to both initialization and transient analysis Total distance tool will travel area under curve Time curve starts to rise Time curve returns to zero If TEND is nonzero VMAX will be computed automatically to satisfy required travel distance DIST Input either TEND or VMAX Rise time Maximum velocity maximum value of curve If VMAX is nonzero TEND will be computed automatically to satisfy required travel distance DIST Input either TEND or VMAX LS DYNA Version 960 DEFINE Remarks See Figure 10 4 4 ar Trise gt dist Velocity 0 0 Tstart Tend Simulation Time Figure 10 4 Smooth curve created automatically using DEFINE_CURVE_SMOOTH This shape is commonly used to control velocity of tools in metal forming applications as shown in the above graph but can be used for other applications in place of any stan
91. Type I Default Remarks VARIABLE DESCRIPTION NEIPH Number of additional integration point history variables written to the LS TAURUS database for solid elements The integration point data is written in the same order that it is stored in memory each material model has its own history variables that are stored For user defined materials it is important to store the history data that is needed for plotting before the data which is not of interest NEIPS Number of additional integration point history variables written to the LS TAURUS database for both shell and thick shell elements for each integration point see NEIPH above LS DYNA Version 960 9 17 DATABASE DATABASE VARIABLE MAXINT STRFLG SIGFLG EPSFLG RLTFLG ENGFLG CMPFLG IEVERP BEAMIP DCOMP 9 18 DATABASE DESCRIPTION Number of shell integration points written to the LS DYNA database see also INTEGRATION_SHELL If the default value of 3 is used then results are output for the outrtmost top and innermost bottom integration points together with results for the neutral axis If MAXINT is set to 3 and the the element has 1 integration point then all three results will be the same If a value other than 3 is used then results for the first MAXINT integration points in the element will be output Note If the element has an even number of integration points and MAXINT is not set to 3 then you will not get mid surface results See R
92. adaptive mesh See the detailed proceduce outlined in the Remarks in the section INTERFACE SPRINGBACK 12 40 ELEMENT LS DYNA Version 960 ELEMENT ELEMENT_TSHELL Purpose Define an eight node thick shell element which is available with either fully reduced or selectively reduced integration rules This element can be used as an alternative to the 4 node shell elements The major use is for transition between shell and solid regions or for modelling thick shells The definition is completed by the PART and SECTION_TSHELL cards The behavior of this shell exhibits excessive stiffness for large radius thickness ratios Card Format 1018 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION EID Element ID Unique numbers have to be used PID Part ID see PART NI Nodal point 1 N2 Nodal point 2 N3 Nodal point 3 N8 Nodal point 8 LS DYNA Version 960 12 41 ELEMENT ELEMENT Remarks 1 The correct numbering of the nodes is essential for correct use Nodes n to define the lower surface and nodes ns to ng define the upper surface If one point integration is used see SECTION_TSHELL the integration points then lie along the t axis as depicted in Figure 12 10 Two by two selective reduced integration is also available Extreme care must be used in defining the connectivity to insure proper orientation 2 The stresses for this shell element are output in the global coordinate system 3 To define a thick shell wedge ele
93. also CONTROL COARSEN Card Format 1 2 3 4 VARIABLE DESCRIPTION BOXID Box ID Define unique numbers XMN Minimum x coordinate XMX Maximum x coordinate YMN Minimum y coordinate YMX Maximum y coordinate ZMN Minimum z coordinate ZMX Maximum z coordinate IFLAG Flag for protecting elements inside or outside of box EQ 0 elements outside box can not be coarsened EQ 1 elements inside box can not be coarsened Remarks 1 Many boxes may be defined If an element is protected by any box then it may not be coarsened LS DYNA Version 960 10 5 DEFINE DEFINE DEFINE BOX DRAWBEAD Purpose Define a specific box shaped volume around a drawbead The box will contain the drawbead nodes and elements between the bead and the outer edge of the blank Elements directly under the bead are also included Card Format 1 2 3 4 fom oom Pw Toft TT pon ee BE VARIABLE DESCRIPTION BOXID Box ID Define unique numbers PID Part ID of blank NSID Node set ID defining nodes that lie along the drawbead IDIR Direction of tooling movement EQ 1 tooling moves in x direction EQ 2 tooling moves in y direction EQ 3 tooling moves in z direction 10 6 DEFINE LS DYNA Version 960 DEFINE DEFINE COORDINATE NODES Purpose Define a local coordinate system with three node numbers The local cartesian coordinate system is defined in the following steps The z axis is co
94. and CONTROL IMPLICIT STABILIZATION keywords LS DYNA Version 960 18 9 INTERFACE INTERFACE 18 10 INTERFACE LS DYNA Version 960 LOAD LOAD The keyword LOAD provides a way of defining applied forces The keyword control cards in this section are defined in alphabetical order LOAD_BEAM_OPTION LOAD_BLAST LOAD_BODY_OPTION LOAD_BODY_GENERALIZED LOAD_BRODE LOAD_DENSITY_DEPTH LOAD_HEAT_GENERATION_OPTION LOAD_MASK LOAD_NODE_OPTION LOAD_RIGID_BODY LOAD_SEGMENT LOAD_SEGMENT_SET LOAD_SHELL_OPTION LOAD_SSA LOAD_SUPERPLASTIC_FORMING LOAD_THERMAL_OPTION LS DYNA Version 960 19 1 LOAD LOAD LOAD_BEAM_OPTION Options include ELEMENT SET urpose Apply the distributed traction load along any local axis of beam or a set of beams The local axes are defined in Figure 19 1 see also ELEMENT_BEAM Card Format 1 2 3 4 3 6 7 8 VARIABLE DESCRIPTION EID ESID Beam ID EID or beam set ID ESID see ELEMENT BEAM or SET_ BEAM DAL Direction of applied load EQ 1 along r axis of beam EQ 2 along s axis of beam EQ 3 along t axis of beam LCID Load curve ID see DEFINE_CURVE SF Load curve scale factor This is for a simple modification of the function values of the load curve 19 2 LOAD LS DYNA Version 960 LOAD Figure 19 1 Applied traction loads are given in force per unit length The s and t directions are defined on the ELEMENT BEAM key
95. and rivets ABSTAT Set dt for airbag statistics NODFOR Set dt for nodal force groups BNDOUT Boundary condition forces and energy RBDOUT Set dt for rigid body data GCEOUT Set dt for geometric contact entities SLEOUT Set dt for sliding interface energy JNTFORC Set dt for joint force file SBTOUT Set dt for seat belt output file AVSFLT Set dt for AVS database MOVIE Set dt for MOVIE MPGS Set dt for MPGS TPRINT Set dt for thermal file LS DYNA Version 960 29 21 RESTART RESTART Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION DT Time interval between outputs EQ 0 0 output interval is unchanged To terminate output to a particular file set DT to a high value 29 22 RESTART LS DYNA Version 960 RESTART DATABASE BINARY OPTION Options for binary output files with the default names given include D3PLOT Dt for complete output states D3THDT Dt for time history data for element subsets D3DUMP Binary output restart files Define output frequency in cycles RUNRSF Binary output restart file Define output frequency in cycles INTFOR Dt for contact surface Interface database Card Format VARIABLE DESCRIPTION DT Time interval between outputs EQ 0 0 Time interval remains unchanged CYCL Output interval in time steps EQ 0 0 output interval remains unchanged LS DYNA Version 960 29 23 RESTART RESTART DELETE OPTION Available options are CONTACT CONTACT 2DAUTO ENTITY PART ELE
96. and set the associated model parameters Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ITRB Select the turbulence model EQ 0 Turbulence models are disabled default EQ 1 Smagorinsky LES sub grid scale model EQ 101 Spalart Almaras model Remarks 1 default value of the Smagorinsky constant is C 0 1 7 26 CONTROL LS DYNA Version 960 CONTROL CONTROL_COARSEN Purpose Adaptively de refine coarsen a shell mesh by selectively merging four adjcent elements into one Adaptive constraints are added and removed as necessary Card Format Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ICOARSE Coarsening flag EQ 0 do not coarsen default EQ 1 coarsen mesh at beginning of simulation ANGLE Allowable angle change between neighboring elements Adjcent elements which are flat to within ANGLE degrees are merged Suggested starting value 8 0 degrees NSEED Number of seed nodes optional 0 use only automatic searching EQ n also search starting with node IDs given below maximum 8 nodes N1 N8 Optional list of seed node IDs for extra searching LS DYNA Version 960 7 27 CONTROL CONTROL Remarks 1 Coarsening is performed at the start of a simulation The first plot state represents the coarsened mesh By setting the termination time to zero and including the keyword INTERFACE_SPRINGBACK_DYNA3D a keyword in
97. and thus can be used to check propellant performance 13 24 EOS LS DYNA Version 960 EOS The reaction rate used for the propellant deflagration process is of the form Z F F p V I F for 0 lt F lt Fir for Fimi lt lt 1 where F is the fraction reacted F 0 implies no reaction F 1 is complete reaction t is time and p is pressure in Mbars r s u w x y and Fjjmir are constants used to describe the pressure dependance and surface area dependence of the reaction rates Two or more pressure dependant reaction rates are included in case the propellant is a mixture or exhibited a sharp change in reaction rate at some pressure or temperature Burning surface area dependences can be approximated using the F Y terms Other forms of the reaction rate law such as Arrhenius temperature dependent E RT type rates can be used but these require very accurate temperatures calculations Although the theoretical justification of pressure dependent burn rates at kilobar type pressures is not complete a vast amount of experimental burn rate versus pressure data does demonstrate this effect and hydrodynamic calculations using pressure dependent burn accurately simulate such experiments The deflagration reactive flow model is activated by any pressure or particle velocity increase on one or more zone boundaries in the reactive material Such an increase creates pressure in those zones and the decomposition be
98. applications CONSTRAINED_POINTS tie any two points together These points must lie on a shell elements Soft constraint is available for edge to edge contact in type 26 contact CONSTAINED_INTERPOLATION option for beam to solid interfaces and for spreading the mass and loads SMP version only A database option has been added that allows the output of added mass for shell elements instead of the time step size A new contact option allows the inclusion of all internal shell edges in contact type CONTACT GENERAL type 26 This option is activated by adding INTERIOR after the GENERAL keyword A new option allows the use deviatoric strain rates rather than total rates in material model 24 for the Cowper Symonds rate model The CADFEM option for ASCII databases is now the default Their option includes more significant figures in the output files When using deformable spot welds the added mass for spot welds is now printed for the case where global mass scaling is activated This output is in the log file D3HSP file and the MESSAG file Initial penetration warnings for edge to edge contact are now written into the MESSAG file and the D3HSP file Each compilation of LS DYNA is given a unique version number 1 10 INTRODUCTION LS DYNA Version 960 INTRODUCTION Finite length discrete beams with various local axes options are now available for material types 66 67 68 93 and 95 In this implementation the absolute value of SCOOR mus
99. available for the Ogden rubber model Lease squares fit to the relaxation curves for the viscoelasticity in rubber Fu Chang rate sensitive foam 6 term Prony series expansion for rate effects in model 57 now 73 Viscoelastic material model 76 implemented for shell elements Mechanical threshold stress MTS plasticity model for rate effects Thermoelastic plastic material model for Hughes Liu beam element Ramberg Osgood soil model Invariant local coordinate systems for shell elements are optional Second order accurate stress updates Four noded linear tetrahedron element Co rotational solid element for foam that can invert without stability problems Improved speed in rigid body to rigid body contacts Improved searching for the a_3 a_5 and al0 contact types Invariant results on shared memory parallel machines with the a_n contact types Thickness offsets in type 8 and 9 tie break contact algorithms Bucket sort frequency can be controlled by a load curve for airbag applications In automatic contact each part ID in the definition may have unique Static coefficient of friction Dynamic coefficient of friction Exponential decay coefficient Viscous friction coefficient Optional contact thickness Optional thickness scale factor Local penalty scale factor Automatic beam to beam shell edge to beam shell edge to shell edge and single surface contact algorithm Release criteria may be a multiple of the shell thickness i
100. axisymmetric solids The type of the element and its formulation is specified through the part ID see PART and the section ID see SECTION SHELL Also the thickness of each element can be specified when applicable on the element cards or else a default thickness value is used from the section definition For orthotropic and anisotropic materials a local material angle variable PSI can be defined which is cumulative with the integration point angles specified in SECTION SHELL Card Format 1018 Card 1 1 2 3 4 5 6 7 8 9 10 dd i idi ii BEN 12 30 ELEMENT LS DYNA Version 960 ELEMENT Optional Card Required if THICKNESS or BETA is specified after the keyword 5E16 0 1 2 3 4 5 6 7 8 9 10 Type F F F F F VARIABLE DESCRIPTION EID Element ID Chose a unique number with respect to other elements PID Part ID see PART NI Nodal point 1 N2 Nodal point 2 N3 Nodal point 3 N4 Nodal point 4 THIC1 Shell thickness at node 1 THIC2 Shell thickness at node 2 THIC3 Shell thickness at node 3 THIC4 Shell thickness at node 4 PSI Orthotropic material angle offset measured from the reference 1 2 element side axis see remark 6 below The angle is given in degrees Remarks 1 Default values in place of zero shell thicknesses are taken from the cross section property definition of the PID see SECTION_SHELL 2 PSI is defined only for orthotropic and anisotropic materials LS DYNA Ve
101. be last The ORTHO option does not apply if the MOVING option is used Purpose Define planar rigid walls with either finite or infinte size FINITE Orthotropic friction can be defined ORTHO Also the plane can possess a mass and an initial velocity MOVING otherwise the wall is assumed to be stationary The FORCES option allows the specification of segments on the rigid walls on which the contact forces are computed In order to achieve a more physical reaction related to the force versus time curve the SOFT value on the FORCES card can be specified Card Format e Cards 1 and 2 are required e Optional Cards and B are required if ORTHO is specified e Optional Card C is required if FINITE is specified e Optional Card D is required if MOVING is specified e Optional Card E is required if FORCES is specified 22 12 RIGIDWALL LS DYNA Version 960 RIGIDWALL Card 1 Required Card 1 1 2 3 4 5 6 7 8 db Lol VARIABLE DESCRIPTION NSID Nodal set ID containing slave nodes see SET_NODE_OPTION 0 all nodes are slave to rigid wall NSIDEX Nodal set ID containing nodes that exempted as slave nodes see SET_ NODE_OPTION BOXID All nodes in box are included as slave nodes to rigid wall see DEFINE_ BOX If options NSID or NSIDEX are active then only the subset of nodes activated by these options are checked to see if they are within the box OFFSET All nodes within a normal offset distance OFFS
102. be freely mixed together SHRF Shear factor This factor is not needed for truss resultant beam discrete beam and cable elements The recommended value for rectangular sections is 5 6 the default is 1 0 QR IRID Quadrature rule or rule number for user defined rule for integrated beams EQ 1 0 one integration point EQ 2 0 2x2 Gauss quadrature default beam EQ 3 0 3x3 Gauss quadrature EQ 4 0 3x3 Lobatto quadrature EQ 5 0 4x4 Gauss quadrature EQ n where Inl is the number of the user defined rule IRID integration rule n is defined using INTEGRATION_BEAM card CST Cross section type not needed for truss resultant beam discrete beam and cable elements EQ 0 0 rectangular EQ 1 0 tubular EQ 2 0 arbitrary user defined integration rule SCOOR Location of triad for tracking the rotation of the discrete beam element see the parameter CID below The force and moment resultants in the output databases are referenced to this triad The flags 3 0 1 0 0 0 1 0 and 3 0 are inactive if the option to update the local system is active in the CID definition EQ 3 0 beam node 1 the angular velocity of node 1 rotates triad EQ 2 0 beam node 1 the angular velocity of node 1 rotates triad but the r axis is adjusted to lie along the line between the two beam nodal points This option is not recommended for zero length discrete beams EQ 1 0 beam node 1 the angular velocity of node 1 rotates triad EQ 0 0 centered betw
103. be picked up This contact does not apply any force to the model Only the slave set and slave set type need be defined for this contact type Generally only the first three cards are defined The force transducer option PENALTY works with penalty type contact algorithms only i e it does not work with the CONSTRAINT or TIED options For these latter options use the CONSTRAINT option 7 FORMING These contacts are mainly used for metal forming applications A connected mesh is not required for the master tooling side but the orienation of the mesh must be in the same direction These contact types are based on the AUTOMATIC type contacts and consequently the performance is better than the original two surface contacts Be a a a Zu Nodal normal projection b Segment based projection Figure 6 3 Nodal normal and segment based projection is used in the contact options LS DYNA Version 960 6 31 CONTACT CONTACT INTERFACE TYPE ID PENCHK ELEMENT FORMULA FOR RELEASE OF PENETRATING TYPE NODAL POINT 1 2 6 7 EIER TEN 3 5 8 9 10 d PENMAX if and only if PENMAX gt 0 without thickness d 1 e 10 if PENMAX 0 d PENMAX if and only if PENMAX gt 0 d 1 e 10 if PENMAX 0 d XPENE thickness of solid element d XPENE thickness of shell element d 0 05 minimum diagonal length d 0 05 minimum diagonal length 3 5 10 thickness d XPENE thickness of solid element 17 and 18
104. be subjected to any other constraints including prescribed motion e g with the BOUNDARY PRESCRIBED MOTION options Card Format VARIABLE DESCRIPTION NSID Nodal set ID see SET NODE OPTION DOF Applicable degrees of freedom EQ 1 x translational degree of freedom EQ 2 y translational degree of freedom EQ 3 z translational degree of freedom EQ 4 x and y translational degrees of freedom EQ 5 y and z translational degrees of freedom EQ 6 z and x translational degrees of freedom 7 and z translational degrees of freedom TF Failure time for nodal constraint set Remarks 1 The masses of the nodes are summed up to determine the total mass of the constrained set It must be noted that the definiton of a nodal rigid body is not possible with this input For nodal rigid bodies the keyword input CONSTRAINED_NODAL_RIGID_BODY_ OPTION must be used 2 When the failure time is reached the nodal constraint becomes inactive and the constrained nodes may move freely LS DYNA Version 960 5 55 CONSTRAINED CONSTRAINED CONSTRAINED NODE SET CONSTRAINED NODAL RIGID BODY CONSTRAINED SPOTWELD Since no rotation is permitted this option should not be used to Behavior is like a rigid beam These options model rigid body behavior that may be used to model spotwelds involves rotations iN M Offset nodes a and b are constrained to move together Figure 5 18 CONSTRAINED NODE
105. below 5 Equation of state coefficient see below RI Equation of state coefficient see below R2 Equation of state coefficient see below R3 Equation of state coefficient see below R4 Equation of state coefficient see below R5 Equation of state coefficient see below ALI equation of state coefficient see below AL2 A52 equation of state coefficient see below AL3 A23 equation of state coefficient see below ALA equation of state coefficient see below LS DYNA Version 960 13 31 EOS EOS VARIABLE ALS BL1 BL2 BL3 BL4 BLS RL2 RL3 RL4 RLS OMEGA VO Remarks DESCRIPTION A355 equation of state coefficient see below equation of state coefficient see below Bm equation of state coefficient see below equation of state coefficient see below B4 equation of state coefficient see below By5 equation of state coefficient see below R31 equation of state coefficient see below R55 equation of state coefficient see below equation of state coefficient see below R34 equation of state coefficient see below R35 equation of state coefficient see below Equation of state coefficient see below Equation of state coefficient see below Energy density per unit initial volume Initial realtive volume The JWLB equation of state defines the pressure as A 0 i 1 5 p Dali Ah E di a whe
106. bodies must share a common edge to define the joint along This edge however must not have the nodes merged together Rigid bodies A and B will rotate relative to each other along the axis defined by the common edge Nodes 1 and 2 are on rigid body A and coincide with nodes 9 and 10 on rigid body B respectively This defines the axis of rotation The relative penalty stiffness on the revolute joint is to be 1 0 the joint is well lubricated thus no damping at the joint is supplied CONSTRAINED JOINT REVOLUIE Note A joint stiffness is not mandatory for this joint to work However to see how a joint stiffness can be defined for this particular joint see the corresponding example listed in CONSTRAINED JOINT STIFFNESS GENERALIZED 5555555555555555555555555555555555555555555555555555555555555555555555555555555 UW Ur Ur UY UY Ur UY Ur UU Ur Ur Ur UY Ur UY UY UY XY Ur UY UY UY UY LS DYNA Version 960 5 33 CONSTRAINED CONSTRAINED CONSTRAINED JOINT STIFFNESS OPTION Options include GENERALIZED FLEXION TORSION Purpose Define optional rotational joint stiffnesses for joints defined by CONSTRAINED JOINT OPTION These definitions apply to all joints even though degrees of freedom that are considered in the joint stiffness capability may constrained out in some joint types The energy that is dissipated with the joint stiffness option is written for each joint in joint force file with the default name JNTFORC In the globa
107. can be assigned for some input types For example for airbags a time delay DA1 T1 can be defined before pressure begins to act along with a time delay DA2 T2 before full pressure is applied default T2 T1 and for the constraint option CONSTRAINED RIGID BODY STOPPERS one attribute can be defined DAI the closure distance which activates the stopper constraint 2 The default part attributes can be overridden on the part cards otherwise Al DAl etc 24 14 SET LS DYNA Version 960 SET SET SEGMENT OPTION Available options include BLANK GENERAL Purpose Define a set of quadrilateral and triangular segments with optional identical or unique attributes Card Format 1 2 3 4 3 6 7 8 se LLL Cards 2 3 4 No option is specified next card terminates the input 1 2 3 4 5 6 7 8 LS DYNA Version 960 24 15 SET SET Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options listed in the table defined below 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID All segment sets should have a unique set ID DAI First segment attribute default value see remark 1 below DA2 Second segment attribute default value DA3 Third segment attribute default value DA4 Fourth segment attribute default value NI Nodal point n N2 Nodal point na N3 Nodal point n3 N4 Nod
108. cards Two cards are defined for this option Card Format Card 1 of 2 1 2 3 4 2 6 7 8 LI ELI Card Format Card 2 of 2 1 2 3 4 5 6 7 8 EEE VARIABLE DESCRIPTION TS Thermal time step code 0 No change EQ 1 Fixed timestep EQ 2 variable timestep DT Thermal time step on restart 0 No change TMIN Minimum thermal timestep 0 No change TMAX Maximum thermal timestep 0 No change DTEMP Maximum temperature change in a thermal timestep EQ 0 No change TSCP Time step control parameter 0 0 lt TSCP lt 1 0 0 No change REFMAX Maximum number of reformations per thermal time step 0 No change 29 10 RESTART LS DYNA Version 960 RESTART VARIABLE DESCRIPTION TOL Non linear convergence tolerance EQ 0 No change LS DYNA Version 960 29 11 RESTART RESTART The VELOCITY NODE option allows the velocity of nodal points to be changed at restart Termination of this input is when the next card is read Card Format 1 2 3 4 5 6 7 8 vine w vm wm me fo fe fe fe fe fe fe VARIABLE DESCRIPTION NID Node ID Translational velocity in x direction VY Translational velocity in y direction VZ Translational velocity in z direction VXR Rotational velocity about the x axis VYR Rotational velocity about the y axis VZR Rotational velocity about the z
109. coef 40 1 00 42 1 1 00 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 5 49 CONSTRAINED CONSTRAINED CONSTRAINED_NODAL_RIGID_BODY_ OPTION If the inertial properties are defined rather than computed then the following option is available INERTIA Purpose Define a nodal rigid body This is a rigid body which consists of the defined nodes If the INERTIA option is not used then the inertia tensor is computed from the nodal masses Arbitrary motion of this rigid body is allowed If the INERTIA option is used constant translational and rotational velocities can be defined in a global or local coordinate system Card Format Card 1 is required Cards 2 4 are required for the INERTIA option Card 5 is required if a local coordinate system is used to specify the inertia tensor when the INERTIA option is used Remarks 1 Unlike the CONSTRAINED_NODE_SET which permits only translational motion here the equations of rigid body dynamics are used to update the motion of the nodes and therefore rotations of the nodal sets are admissible Mass properties are determined from the nodal masses and coordinates Inertial properties are defined if and only if the INERTIA option is specified Card 1 Required Card 1 1 2 3 4 5 6 7 8 tat EN ES VARIABLE DESCRIPTION PID Part ID of the nodal rigid body CID Coordinate system ID for output of data
110. current pressure to avoid instabilities in the time step The virgin loading and completely crushed curves are modeled with monotonic cubic splines An optimized vector interpolation scheme is then used to evaluate the cubic splines The bulk modulus and sound speed are derived from a linear interpolation on the derivatives of the cubic splines LS DYNA Version 960 13 29 EOS EOS EOS JWLB This is Equation of state Form 14 The JWLB Jones Wilkens Lee Baker equation of state developed by Baker 1991 and further described by Baker and Orosz 1991 describes the high pressure regime produced by overdriven detonations while retaining the low pressure expansion behavior required for standard acceleration modeling The derived form of the equation of state is based on the JWL form due to its computational robustness and asymptotic approach to an ideal gas at high expansions Additional exponential terms and a variable Gruneisen parameter have been added to adequately describe the high pressure region above the Chapman Jouguet state Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 Card 3 Card 4 2 3 4 5 6 13 30 EOS LS DYNA Version 960 Card 5 1 2 3 4 5 6 7 8 Card 6 VARIABLE DESCRIPTION EOSID Equation of state label Al Equation of state coefficient see below A2 Equation of state coefficient see below A3 Equation of state coefficient see below A4 Equation of state coefficient see
111. curve defines the maximum time step size permitted versus time If the solution time exceeds the final time value defined by the curve the computed step size is used If the time step size from the load curve is exactly zero the computed time step size is also used Erosion flag for solid and solid shell elements when DTMIN see CONTROL_TERMINATION is reached If this flag is not set the calculation will terminate EQ O no EQ 1 yes LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION MSIST Limit mass scaling to the first step and fix the mass vector according to the time steps once The time step will not be fixed but may drop during the calculation from the specified minimum EQ 0 no EQ 1 yes DT2MSF Reduction or scale factor for initial time step size to determine the minimum time step size permitted Mass scaling is done if it is necessary to meet the Courant time step size criterion If this option is used DT2MS DT2MSF multiplied by the initial time step size At before At is scaled by TSSFAC This option is active if and only if DT2MS 0 above Remarks 1 During the solution we loop through the elements and determine a new time step size by taking the minimum value over all elements At TSSFAC min At At Aty where N is the number of elements The time step size roughly corresponds to the transient time of an acoustic wave through an element using the shortest characteristic distance For sta
112. d XPENE thickness of shell element a3 a5 10 13 15 d PENMAX thickness of solid element default PENMAX 0 5 d PENMAX slave thickness master thickness default PENMAX 0 4 d 0 5 thickness of solid element d 0 4 slave thickness master thickness d PENMAX thickness of solid element default PENMAX 200 0 d PENMAX slave thickness master thickness default PENMAX 200 Table 6 1 Criterion for node release for nodal points which have penetrated too far Larger penalty stiffnesses are recommended for the contact interface which allows nodes to be released For node to surface type contacts 5 5a the element thicknesses which contain the node determines the nodal thickness The parameter is defined on the CONTROL_CONTACT input 6 32 CONTACT LS DYNA Version 960 CONTACT The keyword options for the contact type and the corresponding Version 92X 93X 94X 95X type numbers are STRUCTURED INPUT TYPE ID KEYWORD NAME al3 26 126 a5 a5 210 10 LS DYNA Version 960 AIRBAG_SINGLE_SURFACE AUTOMATIC_GENERAL AUTOMATIC GENERAL INTERIOR AUTOMATIC NODES TO SURFACE AUTOMATIC NODES TO SURFACE TIEBREAK AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE AUTOMATIC SURFACE TO SURFACE TIEBREAK CONSTRAINT NODES TO SURFACE CONSTRAINT SURFACE TO SURFACE DRAWBEAD ERODING NODES TO SURFACE ERODING SURFACE TO SURFACE ERODING SINGLE SURFACE FORCE TRANSDUCER CONSTR
113. define this array manually For the NEIGHBOR option define the following cards Card Format Cards 1 2 3 The next card terminates the input 1 2 3 4 5 6 7 8 HS i TE idi idi EE NE VARIABLE DESCRIPTION NELEM Element number NABORI Neighbor for side 1 of NELEM NABOR2 Neighbor for side 2 of NELEM NABOR3 Neighbor for side 3 of NELEM NABOR4 Neighbor for side 4 of NELEM LS DYNA Version 960 3 13 BOUNDARY BOUNDARY Remarks Each boundary element has 4 sides Figure 3 2 Side 1 connects the 1st and 2nd nodes side 2 connects the 2nd and 3rd nodes etc The 4th side is null for triangular elements node 4 node 3 node 1 node 2 Figure 3 2 Each segment has 4 sides For most elements the specification of neighbors is straightforward For the typical case a quadrilateral element is surrounded by 4 other elements and the neighbor array is as shown in Figure 3 3 neighbor 3 j side 3 segment j side 1 neighbor 4 j side 4 neighbor 2 j neighbor 1 j Figure 3 3 Typical neighbor specification There are several situations for which the user may desire to directly specify the neighbor array for certain elements For example boundary element wakes result in discontinuous doublet distributions and neighbors which cross a wake should not be used Figure 3 4 illustrates a situation where a wake is attached to side 2 of segment j For this situation two opti
114. for the master rigid body e g constraints given velocity are now also valid for the newly created rigid body LS DYNA Version 960 5 59 CONSTRAINED CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 CONSTRAINED RIGID BODIES 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Rigidly connect parts 35 70 71 and 72 to part 12 All parts must be defined as rigid This example is used to make a single rigid body out of the five parts that compose the back end of a vehicle This was done to save cpu time and was determined to be valid because the application was a frontal impact with insignificant rear end deformations The cpu time saved was from making the parts rigid not from merging them merging was more of a convenience in this case for post processing for checking inertial properties and for joining the parts UUr UY Uo UY XY UY Ur UY CONSTRAINED RIGID BODIES Sean Le Da 2 Bra 3 Den iD DD Dr pidm pids 12 35 12 70 12 71 12 72 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 60 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED RIGID BODY STOPPERS Purpose Rigid body stoppers provide a convenient way of controlling the motion of rigid tooling in metalforming applications The motion of a master rigid body is limited by loa
115. here A keyword card with a in column 1 terminates this input Card 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part identification This part must be a rigid body NMFB Number of kept modes in flexible body The number of modes in the file FILENAME must equal or exceed NMFB If KMFLAG 0 the first modes in the file are used FORM Flexible body formulation See remark 5 below EQ 0 exact EQ 1 fast ANSID Attachment node set ID optional FORMAT Input format of modal information EQ 0 NASTRAN pch file EQ 1 LSTC eigout file EQ 2 NASTRAN pch file LS DYNA binary version The binary version of this file is automatically created if a NASTRAN pch file is read The name of the binary file is the name of the NASTRAN pch file but with bin appended The binary file is smaller and can be read much faster KMFLAG Kept mode flag Selects method for identifying modes to keep EQ 0 the first NMFB modes in the file FILENAME are used EQ 1 define NMFB kept modes with additional input NUPDF Nodal update flag If active an attachment node set ANSID must be defined EQ 0 all nodes of of the rigid part are updated each cycle EQ 1 only attachment nodes are fully updated All nodes in the body are output based on the rigid body motion without the addition of the modal displacements For maximum benefit an attachment node set can also be defined with the PART ATTACHMENT NODES option The same attachment node set ID s
116. in compression See remark 4 below TDL Deflection twist for DRO 1 limit in tension See remark 4 below 23 8 SECTION LS DYNA Version 960 SECTION Remarks 1 2 The constants from KD to TDL are optional and do not need to be defined If kg is nonzero the forces computed from the spring elements are assumed to be the static values and are scaled by an amplification factor to obtain the dynamic value Fi tp 0 where V absolute value of the relative velocity between the nodes Vo dynamic test velocity For example if it is known that a component shows a dynamic crush force at 15m s equal to 2 5 times the static crush force use 1 5 and Vo 15 Here clearance defines a compressive displacement which the spring sustains before beginning the force displacement relation given by the load curve defined in the material selection If a non zero clearance is defined the spring is compressive only The deflection limit in compression and tension is restricted in its application to no more than one spring per node subject to this limit and to deformable bodies only For example in the former case if three springs are in series either the center spring or the two end springs may be subject to a limit but not all three When the limiting deflection is reached momentum conservation calculations are performed and a common acceleration is computed in the appropriate direction An error termination will occur if a rigi
117. in internal energy Pressure is defined by ev YyT ev E The volumetric strain ey is given by the natural logarithm of the relative volume Up to 10 points and as few as 2 may be used when defining the tabulated functions LS DYNA will extrapolate to find the pressure if necessary LS DYNA Version 960 13 21 EOS EOS EOS_PROPELLANT_DEFLAGRATION This Equation of state 10 has been added to model airbag propellants Card Format Card 1 1 2 3 4 5 Card 2 Card 3 Card 4 Card 5 13 22 EOS LS DYNA Version 960 VARIABLE A B 2 R2 R3 R5 R6 FMXIG FREQ GROW1 ES1 CVP CVR EETAL CCRIT ENQ TMPO GROW2 LS DYNA Version 960 DESCRIPTION EOS Product JWL coefficient Product JWL coefficient Product JWL coefficient Product JWL coefficient Unreacted Co volume Product wCy Unreacted JWL coefficient Unreacted JWL coefficient Unreacted wCy Unreacted JWL coefficient Unreacted JWL coefficient Initial Fraction Reacted Fo Initial Pressure First burn rate coefficient Pressure Exponent 13t term Exponent on F 15t term Exponent on 1 F 18 term Heat capacity products Heat capacity unreacted Extra not presently used Product co volume Heat of Reaction Initial Temperature 298 K Second burn rate coefficient 13 23 EOS EOS VARIABLE DESCRIPTION AR2 Exponent F 2 4 term ES2 Expone
118. in local system see DEFINE_COORDINATE_OPTION Only necessary if no local system is defined below 5 50 CONSTRAINED LS DYNA Version 960 CONSTRAINED VARIABLE DESCRIPTION NSID Nodal set ID see SET NODE OPTION This nodal set defines the rigid body If NSID 0 then NSID PID i e the node set ID and the part ID are assumed to be identical PNODE An optional possibly massless nodal point located at the mass center of the nodal rigid body The initial nodal coordinates will be reset if necessary to ensure that they lie at the mass center In the output files the coordinates accelerations velocites and displacements of this node will coorespond to the mass center of the nodal rigid body If CID is defined the velocities and accelerations of PNODE will be output in the local system in the D3PLOT and D3THDT files unless PNODE is specified as a negative number in which case the global system is used IPRT Print flag For nodal rigid bodies with more than two nodes the following values apply EQ 0 write data into both MATSUM and RBDOUT EQ 1 write data into RBDOUT file only EQ 2 write data into MATSUM file only EQ 3 do not write data into RBDOUT and MATSUM Printing is suppressed for two noded rigid bodies unless IPRT is set to unity This is to avoid excessively large RBDOUT files when many two noded welds are used Card 2 of 4 Required for the INERTIA option Card 2 1 2 3 4 5 6 7 8 me fet et et et te
119. including rotational Note that the preloaded spring locking spring and any restraints on the motion of the associated nodes are defined in the normal way the action of the pretensioner is merely to cancel the force in one spring until or after it fires With the second type the force in the spring element is canceled out until the pretensioner is activated In this case the spring in question is normally a stiff linear spring which acts as a locking mechanism preventing motion of the seat belt buckle relative to the vehicle A preloaded spring is defined in parallel with the locking spring This type avoids the problem of the buckle being free to drift before the pretensioner is activated To activate the pretensioner the following sequence of events must occur 1 Any one of up to four sensors must be triggered zs Then a user defined time delay occurs 3 Then the pretensioner acts LS DYNA Version 960 12 17 ELEMENT ELEMENT ELEMENT_SEATBELT_RETRACTOR Purpose Define seat belt retractor Card Format 1 2 Second 1 CRENES LI LLCID 2 3 4 5 6 7 8 I VARIABLE DESCRIPTION SBRID Retractor ID A unique number has to be used SBRNID Retractor node ID SBID Seat belt element ID SIDI Sensor ID 1 12 18 ELEMENT LS DYNA Version 960 ELEMENT VARIABLE DESCRIPTION SID2 Sensor ID 2 SID3 Sensor ID 3 SIDA Sensor ID 4 TDEL Time delay after sensor triggers PULL Amount of pull out b
120. interface penalties SLSFAC EQ 0 default 1 RWPNAL Scale factor for rigid wall penalties for treating rigid bodies interacting with fixed rigid walls RWPNAL The penalties are set so that a scale factor of unity should be optimal however this may be very problem dependent If rigid deformable materials switching is used this option should be used if the switched materials are interacting with rigid walls EQ 0 0 rigid bodies interacting with rigid walls are not considered GT 0 0 rigid bodies interact with fixed rigid walls A value of 1 0 is recommended Seven 7 variables are stored for each slave node This can increase memory requirements significantly if all nodes are slaved to the rigid walls ISLCHK Initial penetration check in contact surfaces with indication of initial penetration in output file ISLCHK see remarks below EQ 0 the default is set to 1 EQ 1 no checking EQ 2 full check of initial penetration is performed SHLTHK Shell thickness considered in type surface to surface and node to surface type contact options where options 1 and 2 below activate the new contact algorithms The thickness offsets are always included in single surface constraint method and automatic surface to surface and node to surface contact types See remarks below EQ 0 thickness is not considered EQ 1 thickness is considered but rigid bodies are excluded EQ 2 thickness is considered including rigid bodies PENOPT Penalt
121. is currently restricted to the explicit advection procedures 4 DIVU sets the ceiling on the discrete divergence that is permitted during a simulation when INSOL 1 If the divergence at a given time step exceeds the value set by DIVU then an intermediate projection is performed to return the velocity to a div free state 5 The time weighting variables only apply to the case when INSOL22 on the CONTROL_CFD_GENERAL keyword 6 The MSOL keyword for the CONTROL_CFD_MOMENTUM keyword only applies for INSOL 2 2 on the CONTROL_CFD_GENERAL keyword LS DYNA Version 960 7 19 CONTROL CONTROL CONTROL_CFD_PRESSURE Purpose Set the pressure solver parameters to be used for the incompressible Navier Stokes equations Card Format Card 1 1 2 3 4 5 6 7 8 e ELIT Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IPSOL Set the pressure solver type EQ 0 IPSOL 22 for serial IPSOL 21 for MPP default EQ 10 Sparse direct solver EQ 11 PVS direct solver EQ 20 Jacobi preconditioned conjugate gradient method EQ 21 SSOR preconditioned conjugate gradient method EQ 22 SSOR preconditioned conjugate gradient using the Eisenstat transformation 7 20 CONTROL LS DYNA Version 960 VARIABLE MAXIT ICHKIT IWRT IHIST EPS NVEC ISTAB BETA SID PLEV LCID LS DYNA Version 960 CONTROL DESCRIPTION Set the maximum number of iterations for the pres
122. is not needed Two sided coupling will not work if the interface nodes are merged out Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET SEGMENT Remark For the stability of the acoustic structure coupling the following condition must be satisfied 2p D Pl lt 5 where p is the density of the acoustic medium D is the total thickness of the acoustic elements adjacent to the structural element p is the density and r is the thickness of the structural shell element 3 2 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY AMBIENT EOS Purpose Define load curve driven internal energy and relative volume for ambient elements Card Format 1 2 3 4 5 6 7 8 dnd id iid E E EM mE VARIABLE DESCRIPTION PID Part ID LCI Load curve ID for specific internal energy LC2 Load curve ID for relative volume LS DYNA Version 960 3 3 BOUNDARY BOUNDARY BOUNDARY CONVECTION OPTION Available options are SEGMENT SET Purpose Define convection boundary conditions for a thermal or coupled thermal structural analysis Two cards are defined for each option For the SET option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 3 6 7 8 For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 ET ii Mii UT polo 3 4
123. joint which is required in order to define joint stiffness using the CONSTRAINED JOINT STIFFNESS GENERALIZED keyword DAUUNUUNUNUNUUU WW DEFINE COORDINATE NODES 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 10 30 DEFINE LS DYNA Version 960 DEFINE 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 DEFINE COORDINATE SYSTEM 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Define local coordinate system number 3 using three points origin of local coordinate system is at 35 0 0 0 0 0 The x direction is defined 6 from the local origin to 35 0 5 0 0 0 The x y plane is defined using 6 the vector from the local origin to 20 0 0 0 20 0 along with the local x direction definition 5 5 DEFINE COORDINATE SYSTEM cid Yo Zo Yi 71 3 35 0 0 0 0 0 35 0 5 0 0 0 5 5 Xp Yp Zp 20 0 0 0 20 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 DEFINE COORDINATE VECTOR 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Define local coordinate system number 4 using two vectors 5 Vector 1 is defined from 0 0 0 0 0 0 to 1 0 1 0 0 0 5 Vector 2 is defined from 0 0 0 0 0 0 to 1 0 1 0 1 0 See the c
124. modify the Coulomb friction coefficients according to contact information or to use a friction coefficient database A sample subroutine for treating the friction in contact is provided in Appendix E Card Format 1 2 3 4 5 6 7 8 dii T a mE LS DYNA Version 960 28 1 USER USER Card Format Use as many cards as necessary to define NOCI variables 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IFID Interface number NOC Number of history variables for interface The number should not exceed the length of the array defined on CONTROL_CONTACT NOCI Initialize the first NOCI history variables in the input NOCI must be smaller or equal to NOC First user defined input parameter UC2 Second user defined input parameter UCNOCI Last user defined input parameter 28 2 USER LS DYNA Version 960 USER USER LOADING Purpose Provide a means of applying pressure and force boundary conditions The keyword USER LOADING activates this option Input here is optional with the input being read until the next keyword appears The data read here is to be stored in a common block provided in the user subroutine LOADUD This data is stored and retrieved from the restart files Card Format Insert as many cards as needed The next card terminates input 1 2 3 4 5 6 7 8 1 PARM2 PARM3 PARM4 5 PARM6 PARM7 PARM8 Default none none none none none none none none VARIABLE DESCRIPTION PARMn
125. motion about the vector given by the VID Rotation about the normal axes is permitted EQ 8 rotational motion about the vector given by the VID Rotation about the normal axes is not permitted This option does not apply to rigid bodies EQ 9 y z degrees of freedom for node rotating about the x axis at location OFFSETI OFFSET2 in the yz plane point y z Radial motion is NOT permitted EQ 9 y z degrees of freedom for node rotating about the x axis at location OFFSET1 OFFSET2 in the yz plane point y z Radial motion is permitted EQ 10 z x degrees of freedom for node rotating about the y axis at location OFFSETI OFFSET2 in the zx plane point z x Radial motion is NOT permitted EQ 10 z x degrees of freedom for node rotating about the y axis at location OFFSET1 OFFSET2 in the zx plane point z x Radial motion is permitted EQ 11 x y degrees of freedom for node rotating about the z axis at location OFFSETI OFFSET2 in the xy plane point x y Radial motion is NOT permitted EQ 11 x y degrees of freedom for node rotating about the z axis at location OFFSETI OFFSET2 in the xy plane point x y Radial motion is permitted VAD Velocity Acceleration Displacement flag EQ 0 velocity rigid bodies and nodes EQ 1 acceleration nodes only EQ 2 displacement rigid bodies and nodes EQ 3 velocity versus displacement rigid bodies EQ 4 relative displacement rigid bodies only LCID Load curve ID to describe m
126. node NREACT to allow the reaction force through the steering column or support bracketry to be modelled The jetting force is written to the ASCII ABSTAT file and the binary XTF file LS DYNA Version 960 1 25 AIRBAG AIRBAG Additional card required for LINEAR_FLUID option 1 2 3 4 5 6 7 8 man LCINT LCOUTT LCOUTP LCFIT LCBULK LCID VARIABLE DESCRIPTION BULK K bulk modulus of the fluid in the control volume Constant as a function of time Define if LCBULK 0 RO p density of the fluid LCINT F t input flow curve defining mass per unit time as a function of time see DEFINE_CURVE LCOUTT G t output flow curve defining mass per unit time as a function of time This load curve is optional LCOUTP H p output flow curve defining mass per unit time as a function of pressure This load curve is optional LFIT L t added pressure as a function of time This load curve is optional LCBULK Curve defining the bulk modulus as a function of time This load curve is optional but if defined the constant BULK is not used LCID Load curve ID defining pressure versus time see DEFINE CURVE Remarks If LCID 0 then the pressure is determined from YO P th K vo IE L t where P t Pressure V t Volume of fluid in compressed state 1 26 AIRBAG LS DYNA Version 960 AIRBAG V t V t Volume of fluid in uncompressed state p M t M 0 F t dt G t dt H
127. node Belytschko Schwer beam 2 node simple truss elements 8 node solid shell with four thickness integration points mre NW A N These relative timings are very approximate Each interface node of the sliding interfaces is roughly equivalent to one half zone cycle in cost Figure 1 5 illustrates the relative cost of the various shell formulations in LS DYNA3D BT BIW BL BWC CHL HL BT FHL Fully integrated elements Figure 1 5 Relative cost of the four noded shells available in LS DYNA where is the Belytschko Tsay shell BTW is the Belytschko Tsay shell with the warping stiffness taken from the Belytschko Wong Chiang BWC shell The BL shell is the Belytschko Leviathan shell CHL denotes the Hughes Liu shell HL with one point quadrature and a co rotational formulation FBT is a Belytschko Tsay like shell with full integration FHL is the fully integrated Hughes Liu shell and the CFHL shell is its co rotational version LS DYNA Version 960 1 35 INTRODUCTION INTRODUCTION UNITS The units in LS DYNA must be consistent One way of testing whether a set of units is consistent is to check that 1 force unit 1 mass unit x 1 acceleration unit 1 length unit and that 1 acceleration unit 1 time unit Examples of sets of consistent units are Length unit millimeter millimeter Time unit second millisecond Mass unit kilogram tonne kilogram Force unit Newton Newton kiloNewto
128. normal direction of 2D shell elements is evaluated automatically for AUTOMATIC SURFACE TO SURFACE and AUTOMATIC NODE TO SURFACE contact The user can override the automatic algorithm using NDS or NDM and contact will occur with the positive or negative face of the element For SURFACE IN CONTINUUM contact flow though 2D shell elements is prevented in both directions by default If NDM is set to 1 flow in the direction of the normal is permitted When using AUTOMATIC SURFACE CONTINUUM contact there is no need to mesh the continuum around the structure because contact is not with continnum nodes but with material in the interior of the continuum elements The algorithm works well for Eulerian or ALE elements since the structure does not interfere with remeshing However a structure will usually not penetrate the surface of an ALE continuum since the nodes are Lagrangian normal to the surface Therefore if using an ALE fluid the structure should be initially immersed in the fluid and remain immersed throughout the calculation Penetrating the surface of an Eulerian continuum is not a problem For all types of 2D AUTOMATIC contact eroding materials are treated by default At present subcycling is not possible 6 62 CONTACT LS DYNA Version 960 CONTACT 8 Currently only one special initialization option is available 9 For the thermal option h h if the gap thickness is O lt Lap lt Lmin cont s gap h hona Maa
129. on flow through a porous media are used Blockage of venting area due to contact is considered Gauge pressure when venting begins Number of gas inputs to be defined below Including initial air Load curve ID for inflator mass flow rate eq 0 for gas in the bag at time 0 GT 0 piece wise linear interpolation LT 0 cubic spline interpolation Load curve ID for inflator gas temperature eq 0 for gas in the bag at time 0 GT 0 piece wise linear interpolation LT 0 cubic spline interpolation not used Molecular weight Initial mass fraction of gas component LS DYNA Version 960 VARIABLE A FMASS LS DYNA Version 960 AIRBAG DESCRIPTION Coefficient for molar heat capacity of inflator gas at constant pressure e g Joules mole K Coefficient for molar heat capacity of inflator gas at constant pressure e g Joules mole K2 Coefficient for molar heat capacity of inflator gas at constant pressure e g Joules mole K3 Fraction of additional aspirated mass 1 31 AIRBAG AIRBAG Further additional 2 cards are required for HYBRID_JETTING models The following two additional cards are defined for the HYBRID_JETTING options The jet may be defined by specifying either the coordinates of the jet focal point jet vector head and secondary jet focal point or by specifying three nodes located at these positions The nodal point option is recommended when the location of the airbag changes as a functi
130. only analysis see LOAD THERMAL option Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID NID Nodal set ID or nodal point ID see also SET_NODES 0 all nodes are included set option only TEMP Temperature at node or node set Remark 1 If a nodal temperature is specified more than one input card then the last set input will determine its temperature unless it is specified on a INITIAL_TEMPERATURE_NODE card 16 16 INITIAL LS DYNA Version 960 INITIAL INITIAL_VEHICLE_KINEMATICS Purpose Define initial kinematical information for a vehicle In its initial orientation the vehicle s yaw pitch and roll axes must be aligned with the global axes Successive simple rotations are taken about these body fixed axes Card Format Card 1 1 2 3 4 3 6 7 8 Card 2 1 2 3 4 5 6 7 8 Card 3 1 2 3 4 5 6 7 8 LS DYNA Version 960 16 17 INITIAL INITIAL VARIABLE GRAV PSID XO YO ZO XF YF A 3 AANG BANG CANG WA WC 16 18 INITIAL DESCRIPTION Gravity direction code EQ 1 Global x direction EQ 1 Global x direction EQ 2 Global y direction EQ 2 Global y direction EQ 3 Global z direction EQ 3 Global z direction Note this must be the same for all vehicles present in the model Part set ID x coordinate of initial position of mass center y coordinate of initial position of mass cen
131. orthotropic friction Optional Card A Optional Card B VARIABLE SFRICA SFRICB DFRICA DFRICB DECAYA DECAYB NODEI NODE2 LS DYNA Version 960 1 2 3 4 5 6 7 8 SFRICA SFRICB DFRICA DFRICB DECAYA DECAYB 1 2 NODEI NODE2 Ti gt gt gt E E DESCRIPTION Static friction coefficient in local a direction u see Figure 22 2 Static friction coefficient in local b direction Up Dynamic friction coefficient in local a direction Uya Dynamic friction coefficient in local b direction Decay constant in local a direction dya Decay constant in local b direction dyb Node 1 alternative to definition with vector d below see Figure 22 2 With the node definition the direction changes if the nodal pair rotates Node 2 22 15 RIGIDWALL RIGIDWALL VARIABLE DESCRIPTION DI d x component of vector alternative to definition with nodes above see Figure 23 2 This vector is fixed as a funtion of time D2 42 y component of vector D3 d3 z component of vector b a defintion by nodes definition by vector components node 1 Figure 22 2 Definition of orthotropic friction vectors The two methods of defining the vector d are shown If vector d is defined by nodes 1 and 2 the local coordinate system may rotate with the body which contains the nodes otherwise d is fixed in space thus on the rigid wall and the local system is stationary Remar
132. output SIG Define the IJ stress component EPS Effective plastic strain LS DYNA Version 960 16 11 INITIAL INITIAL INITIAL_STRESS_SHELL Purpose Initialize stresses and plastic strains for shell elements Define as many shell elements in this section as desired The input is assumed to terminate when a new keyword is detected It is not necessary for the location of the through thickness integration points to match those used in the elments which are initialized The data will be interpolated by LS DYNA3D Card Format Card 1 Define NPLANE X NTHICK cards below one per integration point For each through thickness point define NPLANE points NPLANE should be either 1 or 4 corresponding to either 1 or 4 Gauss integration points If four integration points are specified they should be ordered such that their in plane parametric coordinates are at CS _3 S _N3 CS 3 3P m 337 2773 respectively Card 2 16 12 INITIAL LS DYNA Version 960 VARIABLE EID NPLANE NTHICK T SIGij EPS LS DYNA Version 960 INITIAL DESCRIPTION Element ID Number of in plane integration points being output Number of through thickness integration points Parametric coordinate of through thickness integration point between 1 and 1 inclusive Define the ij stress component The stresses are defined in the GLOBAL cartesian system Effective plastic strain 16 13 INITIAL INITIAL
133. p dt Current fluid mass 0 V 0 p Mass of fluid at time zero 0 0 By setting LCID 0 a pressure time history may be specified for the control volume and the mass of fluid within the volume is then calculated from the volume and density This model is for the simulation of hydroforming processes or similar problems The pressure is controlled by the mass flowing into the volume and by the current volume The pressure is uniformly applied to the control volume Note the signs used in the the equation for M t The mass flow should always be defined as positive since the output flow is substracted LS DYNA Version 960 1 27 AIRBAG AIRBAG Additional cards required for HYBRID and HYBRID_JETTING options 1 2 3 ATMOST ATMOSP ATMOSD 1 28 AIRBAG LS DYNA Version 960 AIRBAG Define 2 NGAS cards below two for each gas type VARIABLE ATMOST ATMOSP ATMOSD GC CC C23 LCC23 A23 LS DYNA Version 960 1 2 LCIDM LCIDT 3 4 5 6 7 8 not used DESCRIPTION Atmospheric temperature Atmospheric pressure Atmospheric density Universal molar gas constant Conversion constant EQ 0 Set to 1 0 Vent orifice coefficient which applies to exit hole Set to zero if LCC23 is defined below Load curve number defining the vent orifice coefficient which applies to exit hole as a function of time A nonzero value for C23 overrides LCC23 Vent orifice area which applies to exit hol
134. part attribute the closure distance Dj and D in Figure 5 19 which activates the constraint The constraint does not begin to act until the master rigid body stops If the distance between the master rigid body is less than or equal to the closure distance the slave rigid body motion towards the master rigid body also stops However the slaved rigid body is free to move away from the master If the closure distance is input as zero 0 0 then the slaved rigid body stops when the master stops Optional part set ID of rigid bodies that are slaved in the minimum coordinate direction to the master rigid body In the part set see SET PART DEFINITION definition the COLUMN option may be used to defined as a part attribute the closure distance D and D in Figure 5 11 which activates the constraint The constraint does not begin to act until the master rigid body stops If the distance between the master rigid body is less than or equal to the closure distance the slave rigid body motion towards the master rigid body also stops However the slaved rigid body is free to move away from the master If the closure distance is input as zero 0 0 then the slaved rigid body stops when the master stops Load curve ID which defines the maximum absolute value of the velocity as a function of time that is allowed within the stopper See DEFINE _ CURVE EQ 0 no limitation on the velocity Direction stopper acts in EQ 1 x translation EQ 2 y
135. possible that time can be negative The arc length apply cannot be used with a dynamic analysis In the default BFGS method the global stiffness matrix is only reformed every ILIMIT iterations Otherwise an inexpensive stiffness update is applied By setting ILIMIT 1 a stiffness reformation is performed every iteration This is equivalent to the Full Newton method with line search A higher value of ILIMIT 20 25 can reduce the number of stiffness matrix reformations and factorizations which may lead to a significant reduction in cost The nonlinear equilibrium search will continue until the stiffness matrix has been reformed MAXREF times with ILIMIT iterations between each reformation If equilibrium has not been found control will be passed to the automatic time step controller if it is activated Otherwise error termination will result When the auto time step controller is active it is often efficient to choose MAXREF 5 and try another stepsize quickly rather than wasting too many iterations on a difficult step LS DYNA Version 960 7 53 CONTROL CONTROL DCTOL ECTOL LSTOL DNORM DIVERG ISTIF NLPRT ARCCTL ARCLEN ARCDMP When the displacement ratio shown for each iteration is reduced below DCTOL this condition is satisfied Smaller numbers lead to more strict determination of equilibrium and on the negative side result in more iterations and higher costs When the energy ratio shown for each iterat
136. reached the actual geometry is used to determine the time step size even if RDT is active If RDT is active the time step size will be based on the reference geometry once the solution time exceeds the birth time This option is useful for shrunken bags where the bag does not carry compressive loads and the elements can freely expand before stresses develop If this option is not specified the time step size will be based on the current configuration and will increase as the area of the elements increase The default may be much more expensive but possibly more stable Purpose If the reference configuration of the airbag 1s taken as the folded configuration the geometrical accuracy of the deployed bag will be affected by both the stretching and the compression of elements during the folding process Such element distortions are very difficult to avoid in a folded bag By reading in a reference configuration such as the final unstretched configuration of a deployed bag any distortions in the initial geometry of the folded bag will have no effect on the final geometry of the inflated bag This is because the stresses depend only on the deformation gradient matrix ox 1 where the choice of X coincide with the folded or unfold configurations It is this unfolded configuration which may be specified here Note that a reference geometry which is smaller than the initial airbag geometry will not induce initial tensile s
137. recommended for several reasons First element forces are nearly independent of node sequencing secondly the hourglass modes will not substantially affect the material directions and finally stable calculations over long time periods are achievable 7 4 CONTROL LS DYNA Version 960 CONTROL CONTROL ADAPSTEP Purpose Define control parameters for contact interface force update during each adaptive cycle Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION FACTIN Initial relaxation factor for contact force during each adaptive remesh To turn this option off set FACTIN 1 0 Unless stability problems occur in the contact FACTIN 1 0 is recommended since this option can create some numerical noise in the resultant tooling forces A typical value for this parameter is 0 10 DFACTR Incremental increase of FACTIN during each time step after the adaptive step FACTIN is not allowed to exceed unity A typical value might be 0 01 Remarks 1 This command applies to contact with thickness offsets including contact types CONTACT_ FORMING CONTACT_NODES_TO_SURFACE CONTACT_SURFACE_TO_ SUR FACE and CONTACT ONE WAY SURFACE TO SURFACE LS DYNA Version 960 7 5 CONTROL CONTROL CONTROL_ADAPTIVE Purpose Activate adaptive meshing The parts which are adaptively meshed are defined by PART See remarks below Card Format Card 1 1 2 3 Card Format This card is optional 4 5 6 8 fe eo ee
138. reported as system damping energy in the ASCII file GLSTAT This energy is computed whenever system damping is active 8 4 DAMPING LS DYNA Version 960 DAMPING DAMPING PART STIFFNESS Purpose Assign Rayleigh stiffness damping coefficient by part ID Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID see PART COEF Rayleigh damping coefficient for stiffness weighted damping Values between 0 01 and 0 25 are recommended Higher values are strongly discouraged and values less than 0 01 may have little effect Remarks The damping matrix in Rayleigh damping is defined as C aM BK where C M and K are the damping mass and stiffness matrices respectively The constants and are the mass and stiffness proportional damping constants The mass proportional damping can be treated by system damping see keywords DAMPING_GLOBAL and DAMPING_PART_ MASS Transforming C with the ith eigenvector gives t 2 22 0 mE 0 aM ae Q 20 65 where 00 is the ith frequency radians unit time and amp is the corresponding modal damping parameter Generally the stiffness proportional damping is effective for high frequencies and is orthogonal to rigid body motion Mass proportional damping is more effective for low frequencies and will damp rigid body motion If a large value of the stiffness based damping coefficient is used it may be necessary to lower the time step size signif
139. series of options ALL ELEM DELEM PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID All shell sets should have a unique set ID DAI First attribute default value see remark 1 DA2 Second attribute default value DA3 Third attribute default value DA4 Fourth attribute default value 24 20 SET LS DYNA Version 960 SET VARIABLE DESCRIPTION EID1 First shell element ID see remark 2 EID2 Second shell element ID EID Element ID Al First attribute A2 Second attribute A3 Third attribute A4 Fourth attribute BNBEG First shell ID in shell block N BNEND Last shell ID in block N All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all input is read so that gaps in the element numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not element ID s OPTION Option for GENERAL See table below 1 Specified entity Each card must have the option specified See table below OPTION ENTITY define up to 7 FUNCTION ie ou All shell elements will be included in the set el e2 e3 e4 e5 e7 Elements e1 e2 e3 will be included DELEM el e2 e3 e4 e5 e6 e7 Elements el e2 e3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 will be included DPART pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 previously added
140. set of pressure segments can be repeated in the input with a sign reversal used on the load curve When solid elements are used the pressure segments for each phase will in general be unique This is an ad hoc parameter which should probably not be used The output files named pressure curvel and curve2 may be ploted by LS TAURUS in PHS3 using the SUPERPL command The file curve2 is created only if the second phase is active See DATABASE SUPERPLASTIC FORMING The constraint method contact CONTACT CONSTRAINT NODES TO SURFACE is recommended for superplastic forming simulations since the penalty methods are not as reliable when mass scaling is applied Generally in superplastic simulations mass scaling is used to enable the calculation to be carried out in real time 19 34 LOAD LS DYNA Version 960 LOAD LOAD_THERMAL_OPTION Options include CONSTANT CONSTANT_NODE LOAD_CURVE TOPAZ VARIABLE VARIABLE_NODE Purpose To define nodal temperatures that thermally load the structure Nodal temperatures defined by the LOAD THERMAL OPTION method are all applied in a structural only analysis They are ignored in a thermal only or coupled thermal structural analysis see CONTROL_THERMAL _ OPTION All the LOAD_THERMAL options cannot be used in conjunction with each other Only those of the same thermal load type as defined below in column 2 may be used together LOAD_THERMAL_CONSTANT Thermal load type
141. shell node may be tied to up to nine brick nodes lying along the tangent vector to the nodal fiber See Figure 5 20 During the calculation nodes thus constrained must lie along the fiber but can move relative to each other in the fiber direction The brick nodes must be input in the order in which they occur in either the plus or minus direction as one moves along the shell node fiber This feature is intended to tie four node shells to eight node shells or solids it is not intended for tying eight node shells to eight node solids 5 66 CONSTRAINED LS DYNA Version 960 CONSTRAINED Nodes are constrained to stay on fiber vector Nodes s and coincident Figure 5 20 The interface between shell elements and solids ties shell node s1 to a line of nodes on the solid elements n1 n5 It is very important for the nodes to be aligned 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5856 OONSTRAINED SHELL TO SOLID 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Tie shell element at node 329 to solid element at node 203 nodes 329 and 203 are coincident Additionally define a line of nodes on the solids elements containing node 203 that must remain in the same direction as the fiber of the shell containing node 329 In other words Nodes 119 161 203 245 and 287 are nodes on a solid part that define a line on that solid part
142. solids 1 4 n n n n n 2 3 4 6 node n Figure 12 8 Four six eight node solid elements Nodes 1 4 are on the bottom surface LS DYNA Version 960 12 37 ELEMENT ELEMENT Figure 12 9 Two vectors a and d are defined and the triad is computed and stored Vectors b and d lie in the same plane 12 38 ELEMENT LS DYNA Version 960 ELEMENT ELEMENT_SPH Purpose Define a lumped mass element assigned to a nodal point Card Format 218 E16 0 1 2 3 4 5 6 7 8 9 10 pee elm om TF ER I VARIABLE DESCRIPTION NID Node ID and Element ID are the same for the SPH option PID Part ID to which this node element belongs MASS Mass value LS DYNA Version 960 12 39 ELEMENT ELEMENT ELEMENT_TRIM Purpose Define a part subset to be trimmed by DEFINE_CURVE_TRIM Card Format Card 1 1 2 3 4 5 6 7 8 9 10 111111 VARIABLE DESCRIPTION PSID Part set ID for trimming see SET PART Remarks 1 This command in combination with DEFINE CURVE TRIM trims the requested parts before the job starts 2 In case this command does not exist and only DEFINE CURVE TRIM is available in the input the related parts are trimmed after the job is terminated 3 Pre trimming ELEMENT_TRIM DEFINE CURVE TRIM can handle adaptive mesh and post trimming The keyword DEFINE CURVE TRIM by itself cannot deal with an
143. terminate with a restart file During a restart cpu should be set to the total cpu used up to the current restart plus whatever amount of additional time is wanted When restarting from a dump file the execution line becomes LS DYNA I inf O otf G ptf D dpf R rtf F thf U xtf T tpf A rrd J jif S iff Z isf1 L isf2 B rlf W root E efl X scl C cpu K kill Q option KEYWORD MEMORY nwds where rtf restart filename Restarting adaptive runs requires that the following parameter be specified on the command line LS DYNA R adapt dump01 The adaptive dump files contain all information required to successfully restart so that no other files are needed except when CAD surface data is used When restarting a problem that uses VDA IGES surface data the vda input file must be specified LS DYNA R zadapt dump01 V vda If the data from the last run is to be remapped onto a new mesh then specify Q remap The remap file is the dump file from which the remapping data are taken The remap option is available for brick elements only File name dropouts are permitted for example the following execution lines are acceptable LS DYNA I inf LS DYNA R rtf Default names for the output file binary plot files and the dump file are D3HSP D3PLOT D3THDT and D3DUMP respectively For an analysis using interface segments the execution line in the first analysis is given by LS DYNA I zinf Z isfl and in the second by LS DYNA I zinf L isfl
144. the load curve needs to be extended 555 Note Positive body load acts in the negative direction LOAD BODY Z SD Dr cathe Sitio dle due deus Soe el Sm bs 5 lcid sf lciddr xc yc ZC 5 0 00981 DEFINE CURVE 5 lcid sidr scla sclo offa offo 5 5 abscissa ordinate 0 00 1 000 1000 00 1 000 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 19 9 LOAD LOAD LOAD_BODY_GENERALIZED Purpose Define body force loads due to a prescribed base acceleration or a prescribed angular velocity over a subset of the complete problem The subset is defined by using nodes Card Format Card 1 1 2 3 4 5 6 7 8 EN EIERN EN ELIT Card 2 1 2 3 4 5 6 7 8 fina VARIABLE DESCRIPTION NI Beginning node ID for body force load N2 Ending node ID for body force load LCID Load curve ID see DEFINE CURVE DRLCID Load curve ID for dynamic relaxation phase Only necessary if dynamic relaxation is defined See CONTROL DYNAMIC RELAXATION 19 10 LOAD LS DYNA Version 960 LOAD VARIABLE DESCRIPTION XC X center of rotation Define only for angular velocity YC Y center of rotation Define only for angular velocity ZC Z center of rotation Define only for angular velocity AX Scale factor for acceleration in x direction AY Scale factor for acceleration in y direction AZ Scale f
145. the rigid body in a preprocessor much easier since the local system moves with the nodal points LS DYNA Version 960 5 53 CONSTRAINED CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONSTRAINED NODAL RIGID BODY 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Define rigid body consisting of the nodes nodal set 61 This particular example was used to connect three separate deformable parts Physically these parts were welded together Modeling wise however this joint is quit messy and is most conveniently modeled by making a rigid body using several of the nodes in the area Physically this joint was so strong that weld failure was never of concern CONSIRAINED NODAL RIGID BODY nsid 61 nodal set ID number requires a SET NODE option cid not used in this example output will be in global coordinates SET NODE LIST sid 61 nidi nid2 nid3 nid4 nid5 nid7 nids 823 1057 1174 1931 2124 1961 2101 5555555555555555555555555555555555555555555555555555555555555555555555555555555 UY Ut Ur Ur TU UY UY Ur UY gt UY Ur cto Xr UY Ur XY UY UY UY UY UY B n H Q Q H Q 5 54 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED NODE SET Purpose Define nodal constraint sets for translational motion in global coordinates No rotational coupling See Figure 5 18 Nodal points included in the sets should not
146. the shell elements XPENE Contact surface maximum penetration check multiplier If the penetration of a node through the rigid surface exceeds the product of XPENE and the slave node thickness the node is set free EQ 0 default is set to 4 0 BSORT Number of cycles between bucket sorts The default value is set to 10 but can be much larger e g 50 100 for fully connected surfaces Remarks Thickness offsets do not apply to the rigid surface There is no orientation requirement for the segments in the rigid surface and the surface may be assembled from disjoint but contiguous arbitrarily oriented meshes With disjoint meshes the global searches must be done frequently about every 10 cycles to ensure a smooth movement of a slave node between mesh patches For fully connected meshes this frequency interval can be safely set to 50 200 steps between searches The modified binary database D3PLOT contains the road surface information prior to the state data This information contains NPDS Total number of rigid surface points in problem NRSC Total number of rigid surface contact segments summed over all definitions NSID Number of rigid surface definitions NVELQ Number of words at the end of each binary output state defining the rigid surface motion This equals 6 x NSID if any rigid surface moves or zero if all rigid surfaces are stationary PIDS An array equal in length to NPDS This array defines the ID for each poin
147. the unstretched length a tension force is calculated from the material characteristics and is applied along the current axis of the element to oppose further stretching The unstretched length of the belt is taken as the initial distance between the two nodes defining the position of the element plus the initial slack length 12 14 ELEMENT LS DYNA Version 960 ELEMENT ELEMENT_SEATBELT_ACCELEROMETER Purpose Define seat belt accelerometer The accelerometer is fixed to a rigid body containing the three nodes defined below Card Format 1 2 3 4 5 6 7 8 EHEN EHEN EN EN BEE VARIABLE DESCRIPTION SBACID Accelerometer ID A unique number has to be used NIDI Node 1 ID NID2 Node 2 ID NID3 Node 3 ID IGRAV Gravitational accelerations due to body force loads EQ 0 included in acceleration output EQ 1 removed from acceleration output Remarks The presence of the accelerometer means that the accelerations and velocities of node 1 will be output to all output files in local instead of global coordinates The local coordinate system is defined by the three nodes as follows local x from node 1 to node 2 e local 2 perpendicular to the plane containing nodes 1 2 and 3 2 x Xa where a is from node 1 to node 3 e local y zxx The three nodes should all be part of the same rigid body The local axis then rotates with the body LS DYNA Version 960 12 15 ELEMENT ELEMENT ELEMENT_SEATBELT_P
148. this is not possible the automatic contact algorithms beginning with CONTACT AUTOMATIC all of which include thickness offsets are recommended 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONSTRAINED TIED NODES FAILURE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Tie shell elements together at the nodes specified nodal set 101 The constraint will be broken when the plastic strain at the nodes exceeds 0 085 The four corners of the shells are tied together with failure as opposed In this example four shell elements come together at a common point to the more common method of merging the nodes in the pre processing stage CONSTRAINED TIED NODES FATLURE Sr COG Ss Pe Be Din Baw OG Der hed De 5 nsid eppf 101 0 085 SET NODE LIST sid 101 nidl nid2 nid3 nid4 nid5 nid6 nid7 nid8 775 778 896 897 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 5 74 CONSTRAINED LS DYNA Version 960 CONTACT CONTACT The keyword CONTACT provides a way of treating interaction be between disjoint parts Different types of contact may be defined CONTACT_ OPTIONI _ OPTION2 _ OPTION3 _ OPTION4 CONTACT_ENTITY CONTACT_GEBOD_OPTION CONTACT_INTERIOR CONTACT_RIGID_SURFACE CONTACT_1D CONTACT 2D OPTIONI OPTION2 OPTION3 The first C
149. to n see Figure 22 1 Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION RADCYL Radius of cylinder LENCYL Length of cylinder see Figure 22 1 Only if a valure larger than zero is specified is a finite length assumed LS DYNA Version 960 22 7 RIGIDWALL RIGIDWALL Card 3 Required if SPHERE is specified after the keyword The center of the sphere is identical to the tail of n see Figure 22 1 Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION RADSPH Radius of sphere 22 8 RIGIDWALL LS DYNA Version 960 RIGIDWALL Optional Card A Required if MOTION is specified after the keyword Optional 1 Card A 2 3 4 5 6 7 8 ian il uH ind uH uH 29 VARIABLE DESCRIPTION LCID Stonewall motion curve number see DEFINE CURVE OPT Type of motion EQ 0 velocity specified EQ 1 displacement specified VX x direction cosine of velocity displacement vector VY y direction cosine of velocity displacement vector VZ z direction cosine of velocity displacement vector LS DYNA Version 960 22 9 RIGIDWALL RIGIDWALL T n V L rectangular prism V cylinder m n n flat surface V sphere Figure 22 1 Vector n determines the orientation of the generalized stonewalls For the prescribed motion options the wall can be moved in the direction V as shown 22 10 RIGIDWALL LS DYNA Version 960 5 RIGIDWALL 55555555555555555555555555555555555555555555555555555555555555555
150. translation EQ 3 z translation EQ 4 arbitrary defined by vector VID see below EQ 5 x axis rotation EQ 6 y axis rotation EQ 7 z axis rotation EQ 8 arbitrary defined by vector VID see below Vector for arbitrary orientation of stopper see DEFINE_VECTOR Time at which stopper is activated Time at which stopper is deactivated LS DYNA Version 960 CONSTRAINED Remark The optional definition of part sets in minimum or maximum coordinate direction allows the motion to be controlled in arbitrary direction MASTER C g NSSSSSSSSNSSNNSNNNNSNNSNNSSNNNNNNNNN N RIGID BODY STOPPER Figure 5 19 When the master rigid body reaches the rigid body stopper the velocity component into the stopper is set to zero Slave rigid bodies 1 and 2 also stop if the distance between their mass centers and the master rigid body is less than or equal to the input values Dj and Dg respectively c g center of gravity LS DYNA Version 960 5 63 CONSTRAINED CONSTRAINED CONSTRAINED RIVET Purpose Define massless rivets between non contiguous nodal pairs The nodes must not have the same coordinates The action is such that the distance between the two nodes is kept constant throughout any motion No failure can be specified Card Format 1 2 3 oe VARIABLE DESCRIPTION Node ID N2 Node ID TF Failure time for nodal constraint set Remarks 1 Nodes connected by a rivet cannot be members of anot
151. velocity normal direction only EQ 4 penalty coupling Shell Elements EQ 5 penalty coupling with erosion Solid Elements Coupling direction CTYPE 4 and 5 EQ 1 normal direction compression and tension default EQ 2 normal direction compression only EQ 3 all directions Multi material option CTYPE 4 and 5 EQ 0 couple with all multi material groups EQ 1 couple with material with highest density Start time for coupling End time for coupling Penalty factor CTYPE 4 and 5 only Coefficient of friction DIREC 2 only Minimum volume fraction to activate coupling MCOUP 1 5 45 CONSTRAINED CONSTRAINED VARIABLE DESCRIPTION NORM Shell and segment normal orientation EQ 0 right hand rule default EQ 1 left hand rule CQ Heat transfer coefficeint C HMIN Minimum air gap in heat transfer Apin PFAC Maximum air gap in heat transfer Apax There is no heat transfer above this value Remark The heat flux per unit area 4 18 defined as CAT h gt max h min where AT is the temperature difference between the master and slave sides and where h is the actual air gap 5 46 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED LINEAR Purpose Define linear constraint equations between displacements rotations which can be defined in global coordinate systems For a newer and for more general constraint see CONSTRAINED _ INTERPOLATION Card 1 Required Card 1
152. versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE DLCIDG Load curve ID for y damping scale factor versus rate of rotation in radians per unit time This scale factor scales the o damping moment If zero the scale factor defaults to one See DEFINE CURVE DLCIDBT Load curve ID for B damping torque versus rate of twist If zero damping is not considered See DEFINE CURVE LS DYNA Version 960 5 39 CONSTRAINED CONSTRAINED Card 3 of 4 Required for FLEXION TORSION stiffness Card 3 1 2 3 4 VARIABLE DESCRIPTION ESAL Elastic stiffness per unit radian for friction and stop angles for o rotation see Figure 5 17 If zero friction and stop angles are inactive for a rotation FMAL Frictional moment limiting value for rotation If zero friction is inactive for rotation This option may also be thought of as an elastic plastic spring If a negative value is input then the absolute value is taken as the load curve ID defining the yield moment versus amp rotation see Figure 5 17 ESBT Elastic stiffness per unit radian for friction and stop angles for twist see Figure 5 17 If zero friction and stop angles are inactive for B twist FMBT Frictional moment limiting value for B twist If zero friction is inactive for B twist This option may also be thought of as an elastic plastic spring If a negative value is input then the absolute value is taken as th
153. weight factor Equipotential Start time for smoothing End time for smoothing ALE advection factor 23 21 SECTION SECTION Remarks 1 Element formulations 31 and 32 are used exclusively with the CFD option which requires ISOLTYP 4 on the CONTROL_SOLUTION card In this case ELFORM 31 is used with INSOL 1 ELFORMZ32 is used with INSOL 3 on the CONTROL GENERAL card Note that selection of the element formulation is automatic based on the value of INSOL for the CFD solver 2 The keyword CONTROL SOLID activates automatic sorting of tetrahedron and pentahedron elements into type 10 and 15 element formulation respectively These latter elements are far more stable than the degenerate solid element The sorting in performed internally and is transparent to the user 3 For implicit calculations the following element choices are implemented EQ 1 constant stress solid element EQ 2 fully integrated S R solid See remark 5 below EQ 10 1 point tetrahedron EQ 15 2 point pentahedron element EQ 18 8 point enhanced strain solid element for linear statics only EQ 31 1 point Eulerian Navier Stokes EQ 32 8 point Eulerian Navier Stokes If another element formulation is requested LS DYNA will substitute when possible one of the above in place of the one chosen 4 Element formulations 0 and 9 applicable only to MAT MODIFIED HONEYCOMB behave essentially as nonlinear springs so as to permit severe distortio
154. while values less than 1 0 allow the part to springback more freely over the first few steps For flexible parts with large springback a value of 0 001 may be required EQ n curve n defines SCALE as a function of time TSTART Start time Default immediately upon entering implicit mode TEND End time Default termination time Remarks Artificial stabilization allows springback to occur over several steps This is often necessary to obtain convergence during equilibrium iterations on problems with large springback deformation Stabilization is introduced at the start time TSTART and slowly removed as the end time TEND is approached Intermediate results are not accurate representations of the fully unloaded state The end time TEND must be reached exactly for total springback to be predicted accurately At this time all stabilization has been removed from the simulation IAS The default for IAS depends on the analysis type CONTROL_IMPLICIT_ GENERAL For springback analysis automatic time step control and artificial stabilization are activated by default SCALE This is a penalty scale factor similar to that used in contact interfaces If modified it should be changed in order of magnitude increments at first Large values supress springback until very near the termination time Small values may not stabilize the solution enough to allow equilibrium iterations to converge 7 58 CONTROL LS DYNA Version 960 CONTROL C
155. with nodal rotations 2 x 2 integration for the membrane element Belytschko Schwer integrated beam thin walled Belytschko Schwer integrated beam improved TAURUS database control null material for beams to display springs and seatbelts in TAURUS parallel implementation on Crays and SGI computers coupling to rigid body codes seat belt capability added in 1993 1994 LS DYNA Arbitrary Lagrangian Eulerian brick elements Belytschko Wong Chiang quadrilateral shell element Warping stiffness in the Belytschko Tsay shell element Fast Hughes Liu shell element Fully integrated thick shell element Discrete 3D beam element Generalized dampers Cable modeling Airbag reference geometry Version 960 1 3 INTRODUCTION INTRODUCTION Capabilitie Multiple jet model Generalized joint stiffnesses Enhanced rigid body to rigid body contact Orthotropic rigid walls Time zero mass scaling Coupling with USA Underwater Shock Analysis Layered spot welds with failure based on resultants or plastic strain Fillet welds with failure Butt welds with failure Automatic eroding contact Edge to edge contact Automatic mesh generation with contact entities Drawbead modeling Shells constrained inside brick elements NIKE3D coupling for springback Barlat s anisotropic plasticity Superplastic forming option Rigid body stoppers Keyword input Adaptivity First MPP Massively Parallel version w
156. x y and z translation Mesh expansion constraints PRTYPE 3 4 5 and 7 EQ 0 no constraints EQ 1 constrained x expansion EQ 2 constrained y expansion EQ 3 constrained z expansion EQ 4 constrained x and y expansion EQ 5 constrained y and z expansion EQ 6 constrained z and x expansion EQ 7 constrained x y and z expansion Mesh rotation constraints PRTYPE 3 4 5 and 7 EQ 0 no constraints EQ 1 constrained x rotation EQ 2 constrained y rotation EQ 3 constrained z rotation EQ 4 constrained x and y rotation EQ 5 constrained y and z rotation EQ 6 constrained z and x rotation EQ 7 constrained x y and z rotation 2 7 ALE ALE VARIABLE DESCRIPTION ICOORD Center of mesh expansion and rotation PRTYPE 3 4 5 and 7 EQ 0 at center of gravity EQ 1 at XC YC ZC XC YC ZC Center of mesh expansion EXPLIM Limit ratio for mesh expansion and shrinkage Each cartesian direction is treated separately The distance between the nodes is not allowed to increase by more than a factor EXPLIM or decrease to less than a factor 1 EXPLIM 2 8 ALE LS DYNA Version 960 ALE ALE REFERENCE SYSTEM NODE Purpose The purpose of this command is to define a group of nodes that control the motion of an ALE mesh Card Format Card 1 1 2 3 4 5 6 7 8 fo pe fof Card Format Card 1 1 2 3 4 5 6 7 8 NID3 NID5 NID2 NID4 Card Format Card 1 1 LS DYNA Version 960 2 9
157. y and z directions 4 8 COMPONENT LS DYNA Version 960 COMPONENT Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 mm fe fete fe fe EEE EN VARIABLE DESCRIPTION HX HY HZ Initial global x y and z coordinate values of the H point RX RY RZ Initial rotation of dummy about the H point with respect to the global x y and z axes degrees 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 COMPONENT HYBRIDIII 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 A 50th percentile adult rigid HYBRID III dummy with ID number of 7 is defined in the lbf sec 2 inch sec system of units The dummy assigned an initial velocity of 616 in sec in the negative x direction The H point is initially situated at 2 38 20 0 and the dummy is rotated 18 degrees about the global x axis WU UU Ur Ur Ur COMPONENT HYBRIDIII did size units defrm vy vZ 7 2 1 1 616 0 0 5 hx hy hz rx ry rz 38 20 0 18 0 0 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 4 9 COMPONENT COMPONENT COMPONENT HYBRIDIII JOINT OPTION Purpose Alter the joint characteristics of a HYBRID III dummy Setting a joint parameter value to zero retains the default value set internally The following options are available LUMBAR LOWER NECK UPPER NECK LEFT SHOULDER RIGHT SHOULDER LEFT ELBOW RI
158. zero i e C C 0 Internal energy E is increased according to an energy deposition rate versus time curve whose ID is defined in the input LS DYNA Version 960 13 13 EOS EOS EOS IGNITION AND GROWTH OF REACTION IN HE Card Format Card 1 1 2 Variable EOSID Card 2 Variable Type Card 3 Variable Type Card 4 Variable Type VARIABLE DESCRIPTION EOSID Equation of state label A B 13 14 5 LS DYNA Version 960 EOS VARIABLE DESCRIPTION XP2 FRER G R2 R3 R5 R6 FMXIG FREQ GROWI EM ARI ES1 CVP Heat capacity of reaction products CVR Heat capacity of unreacted HE EETAL CCRIT ENQ Heat of reaction TMPO Initial temperature K GROW2 AR2 ES2 EN FMXGR FMNGR LS DYNA Version 960 13 15 EOS EOS Remarks Equation of State Form 7 is used to calculate the shock initiation or failure to initiate and detonation wave propagation of solid high explosives It should be used instead of the ideal HE burn options whenever there is a question whether the HE will react there is a finite time required for a shock wave to build up to detonation and or there is a finite thickness of the chemical reaction zone in a detonation wave At relatively low initial pressures 2 3 GPa this equation of state should be used with material type 10 for accurate calculations of the unreacted HE behavior At higher initial pressures material type 9 can be
159. zero and at time 999 OFFA with the function values set to zero If DATTYP 1 then the offsets do not create these additional points Negative offsets for the abcissa simply shifts the abcissa values without creating additional points Load curves are not extrapolated by LS DYNA for applied loads such as pressures concentrated forces displacement boundary condtions etc Function values are set to zero if the time etc goes off scale Therefore extreme care must be observed when defining load curves In the constitutive models extrapolation is employed if the values on the abcissa go off scale The load curve offsets and scale factors are ignored during restarts if the curve is redefined See CHANGE_CURVE_DEFINITION in the restart section 10 12 DEFINE LS DYNA Version 960 DEFINE DEFINE CURVE FEEDBACK Purpose Define information that is used as the solution evolves to scale the ordinate values of the specified load curve ID One application for this capability is in sheet metal stamping Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION LCID ID number for load curve to be scaled PID Active part ID for load curve control BOXID Box ID Elements of specified part ID contained in box are checked If the box ID is set to zero the all elements of the active part are checked FLDID Load curve ID which defines the flow limit diagram as shown in Figure 10 3 If the product of FSL and the ordinate val
160. 0 DEFORMABLE TO RIGID DEFORMABLE TO RIGID AUTOMATIC Purpose Define a set of parts to be switched to rigid or to deformable at some stage in the calculation Card Format Card 1 SWSET CODE TIME 1 TIME 2 TIME 3 ENTNO RELSW PAIRED Card 2 LS DYNA Version 960 11 3 DEFORMABLE_TO_RIGID DEFORMABLE TO RIGID VARIABLE SWSET CODE TIME 1 TIME 2 TIME 3 ENTNO RELSW PAIRED NRBF NCSF DESCRIPTION Set number for this automatic switch set Must be unique Activation switch code Defines the test to activate the automatic material switch of the part EQ 0 switch takes place at time 1 EQ 1 switch takes place between time 1 and time 2 if rigid wall force specified below is zero EQ 2 switch takes place between time 1 and time 2 if contact surface force specified below is zero EQ 3 switch takes place between time 1 and time 2 if rigid wall force specified below is non zero EQ 4 switch takes place between time 1 and time 2 if contact surface force specified below is non zero Switch will not take place before this time Switch will not take place after this time 0 Time 2 set to 1 0e20 Delay period After this part switch has taken place another automatic switch will not take place for the duration of the delay period If set to zero a part switch may take place immediately after this switch Rigid wall contact surface number for switch codes 1 2 3
161. 0 Figure 10 2 Definition of the coordinate system with two vectors 10 10 DEFINE LS DYNA Version 960 DEFINE DEFINE CURVE Purpose Define a curve for example load ordinate value versus time abcissa value often referred to as a load curve Card Format 1 2 3 4 5 6 7 8 2 3 4 etc Put one pair of points card 2E20 0 Input is terminated when a card is found Use only two points for applying loads if the implicit arc length method is active 1 2 3 4 5 6 7 8 me foe foe VARIABLE DESCRIPTION LCID Load curve ID Tables see DEFINE_TABLE and load curves may not share common ID s LS DYNA3D allows load curve ID s and table ID s to be used interchangeably A unique number has to be defined Note The magnitude of LCID is restricted to 5 significant digits This limitation will be removed in a future release of LS DYNA3D SIDR Stress initialization by dynamic relaxation EQ 0 load curve used in transient analysis only or for other applications EQ 1 load curve used in stress initialization but not transient analysis EQ 2 load curve applies to both initialization and transient analysis LS DYNA Version 960 10 11 DEFINE DEFINE VARIABLE DESCRIPTION SFA Scale factor for abcissa value This is useful for simple modifications EQ 0 0 default set to 1 0 SFO Scale factor for ordinate value function This
162. 0 no damping GT 0 viscous damping in percent of critical e g 20 for 20 damping EQ n Inl is the load curve ID giving the damping force versus relative normal velocity see remark 1 below CF Coulomb friction coefficient see remark 2 below Assumed to be constant INTORD Integration order slaved materials only EQ 0 check nodes only EQ 1 1 point integration over segments EQ 2 2x2 integration EQ 3 3x3 integration EQ 4 4x4 integration EQ 5 5x5 integration This option allows a check of the penetration of the dummy segment into the deformable slaved material Then virtual nodes at the location of the integration points are checked 6 48 CONTACT LS DYNA Version 960 CONTACT Card 2 Format Card 2 1 2 3 4 5 6 7 8 i VARIABLE DESCRIPTION BT Birth time DT Death time so Flag to use penalty stiffness as in surface to surface contact 0 contact entity stiffness formulation EQ 1 surface to surface contact method EQ n Inl is the load curve ID giving the force versus the normal penetration Remarks l The optional load curves that are defined for damping versus relative normal velocity and for force versus normal penetration should be defined in the positive quadrant The sign for the damping force depends on the direction of the relative velocity and the treatment is symmetric if the damping curve is in the positive quadrant If the damping force is defined in the negativ
163. 00 00 8 94 soft ssid nodel node2 node3 node4 0 0 99999 NODE SD eod ee 2 aes Ah ts Die tel Darts he DB nid x y 2 tc rc 99999 250 0 0 0 0 0 0 0 DATARASE HISTORY NODE Define nodes that output into nodout idi id2 id3 Scat eee RER east Ou ec P Redeem Pate aD aeu Dunst edu e 99999 DATABASE NODOUT dt 0 1 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 22 21 RIGIDWALL RIGIDWALL 22 22 RIGIDWALL LS DYNA Version 960 SECTION SECTION In this section the element formulation integration rule nodal thicknesses and cross sectional properties are defined All section identifiers SECID s defined in this section must be unique i e if anumber is used as a section ID for a beam element then this number cannot be used again as a section ID for a solid element The keyword cards in this section are defined in alphabetical order SECTION BEAM SECTION DISCRETE SECTION SEATBELT SECTION SHELL OPTION SECTION SOLID OPTION SECTION SPH SECTION TSHELL The location and order of these cards in the input file are arbitrary An additional option TITLE may be appended to all the SECTION keywords If this option is used then an addition line is read for each section in 80a format which can be used to describe the section At present LS DYNA does make use of the title Inclusion of titles g
164. 1 2 3 e LII Card 2 Define NUM cards below one card for each nodal point Card 2 1 2 3 4 2 6 7 e pe e e e e e ee 1 VARIABLE DESCRIPTION NUM Number of nodes in equation NID Node ID Define only one nonzero number for parameters DOFX DOFY DOFZ DOFRX DOFRY and DOFRZ DOFX Insert 1 0 for no translational constraint in x direction DOFY Insert 1 0 for no translational constraint in y direction DOFZ Insert 1 0 for no translational constraint in z direction DOFRX Insert 1 0 for no rotational constraint about x axis LS DYNA Version 960 5 47 CONSTRAINED CONSTRAINED VARIABLE DESCRIPTION DOFRY Insert 1 0 for no rotational constraint about y axis DOFRZ Insert 1 0 for no rotational constraint about z axis COEF Nonzero coefficient Ck Remarks Nodes of a nodal constraint equation cannot be members of another constraint equation or constraint set that constrain the same degrees of freedom a tied interface or a rigid body i e nodes cannot be subjected to multiple independent and possibly conflicting constraints Also care must be taken to ensure that single point constraints applied to nodes in a constraint equation do not conflict with the constraint sets constrained degrees of freedom In this section linear constraint equations of the form gt C k l can be defined where are the displacements and Cy are user defined coefficients Unles
165. 1 HOURGL ASS nase een ad eet peut ee Meet 14 1 INCLUDE iniu na ER nee rung 15 1 INCEUDE OPTION re o te a E OD IRE 15 1 INITIAL 5e 16 1 Hb edle tate eo 16 2 INITIAL DETONATION bie cscs oi npn t tert ettet genen 16 4 INITIAL FOAM REFERENCE 16 7 INITIAE utr rt rrr este tees cree ee op ae 16 8 SINITIAL AS TRAIN eere teet REN 16 9 vi LS DYNA Version 960 TABLE OF CONTENTS etu cede cius bs dave epe kon Suse 16 10 MINTINAT STRESS SHED 16 12 MINT DIALS TRESS GORID 16 14 INITIAL TEMPERATURE OPTION 0 cs sssscsssssssssssssssssssssessssssessesssssesstsssesssessess 16 16 INITIAL_VEHICLE_KINEMATICS zoo ae 16 17 MINIT IAT VELOCITY ee apo antt ich cn E ech e E cafe ei 16 20 INTIAL VELOCITY NODE ara 16 22 INITIAL_VELOCITY_GENERATION 2224 2022 000001 00101000 16 23 EV OLDS OPTION ee 16 25 INITIAL VOLUME FRACTION 16 26 FIN TEG RANI ON aa Ns 17 1 ATION BEAM scenery Deere 17 1 ES See ee 17 6 PIN TE REACH a sn ea 18 1 INTERFACE_COMPONENT_OPTION 0 ssscsssssssssssssssssssssesssssessssssecssscsesssec
166. 1 FTRANSLATE_ANSYS_OPTION cc ccccccccccccccsccccesccscsscescescescesesseecescuscessscescesevs 27 1 TRANSLATE IDEAS anes techalkensse 27 3 TRANSLATEUNAS TRAN sss 2 22 28 2 aan 27 5 TUSER ZAW He ee nie 28 1 USER INTERFACEVOPRTION TLR RS 28 1 USER EOADEINGIE 4 22 24 Pad eee BE Be Beh de TRI EIN ees 28 3 RESTART INPUT Ver essen E 29 1 2d Goes tede Se vic ee fee 29 3 CONTROL DYNAMIC 29 16 tuere se ea tes 29 18 CONTROL TIMESTBPB iecit eet Rd aan anni 29 19 DAMPBING GEOB Alors poet eto teret Dann 29 20 DATABASE OP TIONG ese EE DOSE 29 21 DATABASE BINARY OPTION en 29 23 DELETE OPTION nii S 29 24 INTEREACE 555 29 26 RIGID DEFORMABLE 29 28 STRESS INITIALIZATION OPTION eene eee Henne 29 31 TERMINATION OPTION 5 1 ttr er ehe tbe x e ae tete preise loei bibet enue 29 34 ayes crock a eo eb esee tese tte
167. 1 do not map thickness PSTRN Plastic strain remap 0 map plastic strain EQ 1 do not plastic strain STRAIN Strain remap 0 map strains EQ 1 do not map strains NIS First of 3 nodes need to reorient the stamped part N2S Second of 3 nodes need to reorient the stamped part N3S Third of 3 nodes need to reorient the stamped part NIC First of 3 nodes need to reorient the crash model part N2C Second of 3 nodes need to reorient the crash model part LS DYNA Version 960 15 3 INCLUDE INCLUDE VARIABLE DESCRIPTION N3C Third of 3 nodes need to reorient the crash model part IDNOFF Offset to node ID IDEOFF Offset to element ID IDPOFF Offset to part ID nodal rigid body ID and constrained nodal set ID IDMOFF Offset to material ID IDSOFF Offset to set ID IDFOFF Offset to function ID or table ID IDDOFF Offset to any ID defined through DEFINE except the FUNCTION option IDROFF Offset to section ID hourglass ID and any equation of state ID FCTMAS Mass transformation factor For example FCTMAS 1000 when the original mass units are in tons and the new unit is kg FCTTIM Time transformation factor For example FCTTIM 001 when the original time units are in milliseconds and the new time unit is seconds FCTLEN Length transformation factor FCTTEM Temperature transformation factor F to C Farenheit to Centigrad C to F F to K K to F and so on INCOUT Set to 1 for the creation of a file DYNA INC
168. 1 0 TSCP Time step control parameter The thermal time step is decreased by this factor if convergence is not obtained 0 TSCP 1 0 EQ 0 0 set to a factor of 0 5 7 80 CONTROL LS DYNA Version 960 CONTROL CONTROL_TIMESTEP Purpose Set structural time step size control using different options Card Format 1 2 3 4 5 6 7 8 Card Format This card is optional Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION DTINIT Initial time step size EQ 0 0 LS DYNA determines initial step size TSSFAC Scale factor for computed time step old name SCFT See Remark 1 below Default 90 if high explosives are used the default is lowered to 67 LS DYNA Version 960 7 81 CONTROL CONTROL VARIABLE ISDO TSLIMT DT2MS LCTM ERODE 7 82 CONTROL DESCRIPTION Basis of time size calculation for 4 node shell elements 3 node shells use the shortest altitude for options 0 1 and the shortest side for option 2 This option has no relevance to solid elements which use a length based on the element volume divided by the largest surface area 0 characteristic length area minimum of the longest side or the longest diagonal EQ 1 characteristic length area longest diagonal EQ 2 based on bar wave speed and MAX shortest side area minimum of the longest side or the longest diagonal THIS LAST OPTION CAN GIVE A MUCH LARGER TIME STEP SIZE THAT CAN LEAD TO INSTABILITIES IN SOME
169. 1f the gap thickness is Lnn SL S Lmax cond h 0 if the gap thickness is gt max The remaining discussion applies to the SLIDING_ONLY TIED_SLIDING SLIDING_ VOIDS PENALTY_FRICTION and PENALTY options These options were adopted from LS DYNA2D and originated in the public domain version of DYNA2D from the Lawrence Livermore National Laboratory The AUTOMATIC contact options are generally recommended excepted for the TIED option Consider two slideline surfaces in contact It is necessary to designate one as a slave surface and the other as a master surface Nodal points defining the slave surface are called slave nodes and similarly nodes defining the master surface are called master nodes Each slave master surface combination is referred to as a slideline Many potential problems with the algorithm can be avoided by observing the following precautions LS DYNA Metallic materials should contain the master surface along high explosive metal interfaces Sliding only type slidelines are appropriate along high explosive metal interfaces The penalty formulation is not recommended along such interfaces If one surface is more finely zoned it should be used as the slave surface If penalty slidelines are used PENALTY and PENALTY_FRICTION the slave master distinction is irrelevant A slave node may have more than one master segment and may be included as a member of a master segment if a slideline intersection is defi
170. 2 2 0 20 00010 01 3 4 BOUND RY CYCLIC Eee ee 3 6 BOUNDARY ELEMENT METHOD OPTION 0 cccccsscscscssssssesesesssesesesssssseevevsvevees 3 8 BOUNDARSSFLUXN OPTION etes e M EL 3 19 BOUNDARY MCOD eT n tte EE 3 22 BOUNDARY NON 0 2 4444 0000 10001 0000 3 24 BOUNDARY NON REFLECTING 20 00222 4 41422 00 1000 0 00 0 eren 3 25 BOUNDARY OUTFLOW CFD OPTION 3 27 BOUNDARY PRESCRIBED OPTION 3 29 BOUNDARY PRESCRIBED MOTION OPTION nn 3 31 BOUNDARY PRESSURE CRD SET ose d RR HER ERR OR HR ERES 3 35 BOUNDARY PRESSURE OUTFLOW OPTION 3 37 BOUNDARY RADIATION 3 39 BOUNDARY SLIDING PLANB c orti ehe e Une e Rn 3 43 BOUNDARY SPC ORTION MA EO RR 3 44 BOUNDARY SYMMETRY 3 46 BOUNDARY TEMPERATURE OPTION 3 47 BOUNDARY THERMAL WELD eee 3 48 SBOUNDARY USA SURFACE aa RO RU odd 3 51 Nee 4 1 COMPONENT GEBOD 222000000 000020 tnter testen 4 2 COMPONENT GEBOD JOINT OPTION 0 c ccccscscssssesesesesesssssssesessecssseesessvsvsesssveees 44 SCONPONENTCHYBRIDLD usa 4 8 COMPONENT HYBRIDIII JOINT OPTION ees 4 10 VCONS TRAINED s See else 5 1 CONSTRAINED ADAPTIVETY ans 5 2 CONSTRAINED EXTRA NODES OPTION 5 3 CONSTRAINED GENERALIZED WELD OPTIO
171. 2 1 2 3 4 5 6 7 8 Type Default Define the following card if and only if NSIDEX gt 0 1 6 7 8 Variable VZRE VARIABLE DESCRIPTION NSID Nodal set ID see SET_NODES containing nodes for initial velocity 16 20 INITIAL LS DYNA Version 960 INITIAL VARIABLE DESCRIPTION NSIDEX Nodal set I see SET_NODES containing nodes that are exempted from the imposed velocities and may have other initial velocities BOXID All nodes in box which belong to NSID are initialized Nodes outside the box are not initialized Exempted nodes are initialized to velocities defined by VXE VYE and VZE below regardless of their location relative to the box VX Initial velocity in x direction VY Initial velocity in y direction VZ Initial velocity in z direction VXR Initial rotational velocity about the x axis VYR Initial rotational velocity about the y axis VZR Initial rotational velocity about the z axis VXE Initial velocity in x direction of exempted nodes VYE Initial velocity in y direction of exempted nodes VZE Initial velocity in z direction of exempted nodes VXRE Initial rotational velocity in x direction of exempted nodes VYRE Initial rotational velocity in y direction of exempted nodes VZRE Initial rotational velocity in z direction of exempted nodes Remarks 1 This generation input must not be used with INITIAL_VELOCITY_GENERATION keyword 2 If a node is initialized on than one input card set th
172. 2 3 4 5 6 7 8 ee ee VARIABLE DESCRIPTION DID Dummy ID see COMPONENT_GEBOD_OPTION LCi Load curve ID specifying the loading torque versus rotation in radians for the i th degree of freedom of the joint 4 4 COMPONENT LS DYNA Version 960 COMPONENT VARIABLE DESCRIPTION SCFi Scale factor applied to the load curve of the i th joint degree of freedom Card 2 Required 1 2 3 4 5 6 7 8 w eje eefe VARIABLE DESCRIPTION Ci Linear viscous damping coefficient applied to the i th DOF of the joint Units are torque time radian where the units of torque and time depend on the choice of UNITS in card 1 of COMPONENT_GEBOD_OPTION NEUTi Neutral angle degrees of joint s i th DOF Card 3 Required 1 2 3 4 5 6 7 8 LOSA1 HISA1 LOSA2 HISA2 LOSA3 HISA3 EMEN VARIABLE DESCRIPTION LOSAi Value of the low stop angle degrees for the i th DOF of this joint HISAi Value of the high stop angle degrees for the i th DOF of this joint LS DYNA Version 960 4 5 COMPONENT COMPONENT Card 4 Required 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION UNKi Unloading stiffness torque radian for the i th degree of freedom of the joint This must be a positive number Units of torque depend on the choice of UNITS in card 1 of COMPONENT_GEBOD_OPTION 4 6 COMPONENT LS DYNA Version 960 COMPONENT 5 555555555555555555555555555555555555555
173. 2 NID3 NID4 NID5 NID6 NID7 NID8 24 8 SET LS DYNA Version 960 SET Cards 2 3 4 OPTIONZCOLUMN The next card terminates the input 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION LIST_GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIEND B2BEG B2END B3BEG B3END B4BEG B4END Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options ALL NODE DNODE PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set identification All node sets should have a unique set ID DAI First nodal attribute default value see remark 1 below DA2 Second nodal attribute default value DA3 Third nodal attribute default value LS DYNA Version 960 24 9 SET SET VARIABLE DESCRIPTION DA4 Fourth nodal attribute default value NIDN Node NID Nodal ID Al First nodal attribute see remark 2 below A2 Second nodal attribute A3 Third nodal attribute A4 Fourth nodal attribute BNBEG First node ID in block N BNEND Last node ID in block n All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all input is read so that gaps in the node numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not nodal ID s OPTION Option for GENERAL See table below El E7 Specified entity Each ca
174. 2D plane strain shell element 2D axisymmetric shell element Full contact support in 2D tied sliding only penalty and constraint techniques Most material types supported for 2D elements Interactive remeshing and graphics options available for 2D Subsystem definitions for energy and momentum output Boundary element method for incompressible fluid dynamics and fluid structure interaction problems apap ics added during 1997 1998 in Version 950 Adaptive refinement can be based on tooling curvature with FORMING contact The display of drawbeads is now possible since the drawbead data is output into the D3PLOT database An adaptive box option DEFINE_BOX_ADAPTIVE allows control over the refinement level and location of elements to be adapted A root identification file ADAPT RID gives the parent element ID for adapted elements Draw bead box option DEFINE BOX DRAWBEAD simplifies drawbead input The new control option CONTROL IMPLICIT activates an implicit solution scheme 2D Arbitrary Lagrangian Eulerian elements are available 2D automatic contact is defined by listing part ID s 2D r adaptivity for plane strain and axisymmetric forging simulations is available 2D automatic non interactive rezoning as in LS DYNA2D 2D plane strain and axisymmetric element with 2x2 selective reduced integration are implemented Implicit 2D solid and plane strain elements are available Implicit 2D contact is available The new keyword DELETE C
175. 3 Element formulations can change 4 Three nodes on each part are used to reorient the stamped part for the mapping of the strain and thickness distributions After reorientation the three nodes on each part should approximately coincide 5 The number of in plane integrations points can change 6 The number of through thickness integration points can change Full interpolation is used 7 The node and element ID s between the stamped part and the crash part do not need to be unique The TRANSFORM option allows for node element and set ID s to be offset and for coordinates and constitutive parameters to be transformed and scaled Card Format The card is required Card 1 1 LS DYNA Version 960 15 1 INCLUDE INCLUDE If the STAMPED_PART option is active then define the following input Card Format for the STAMPED_PART option Card 2 1 2 3 4 5 6 7 8 If the TRANSFORM option is active then define the following input Card Format for the TRANSFORM option Card 2 1 8 3 1 15 2 INCLUDE LS DYNA Version 960 INCLUDE Card 4 1 2 3 4 5 6 7 8 Card 5 VARIABLE DESCRIPTION FILENAME File name of file to be included in this keyword file 80 characters maximum If the STAMPED_PART option is active this is the DYNAIN file containing the results from metal stamping PID Part ID of crash part for remapping THICK Thickness remap 0 map thickness EQ
176. 399810 5384693 8622363 5384693 9061798 9324695 9491080 9602896 9681602 9739066 6612094 7415312 7966665 8360311 8650634 2386192 4058452 5255324 6133714 6794096 2386192 0 1834346 3242534 4333954 6612094 4058452 1834346 0 0 1488743 9324695 7415312 5255324 3242534 1488743 9491080 7966665 6133714 4333954 9602896 8360311 6794096 9681602 8650634 9739066 Location of through thickness Gauss integration points The coordinate is referenced to the shell midsurface at location 0 The inner surface of the shell is at 1 and the outer surface is at 1 23 16 SECTION LS DYNA Version 960 NUMBER OF INTEG POINT 1 2 3 4 5 NUMBER OF INTEG POINT SECTION LOBAT TO INTEGRATION RULE 3 POINT 4 POINT 5 POINT 0 MP f 1 0 4472136 1 0 4472136 6546537 1 0 6546537 1 0 6 POINT 7 POINT 8 POINT 9 POINT 10 POINT 1 0 1 0 1 0 1 0 1 0 7650553 8302239 8717401 8997580 9195339 2852315 4688488 5917002 6771863 7387739 2852315 0 2092992 3631175 4779249 7650553 4688488 2092992 0 1652790 1 0 8302239 5917002 3631175 1652790 1 0 8717401 6771863 4779249 1 0 8997580 7387739 1 0 9195339 1 0 Location of through thickness Lobatto integration points The coordinate is referenced to the shell midsurface at location 0 The inner surface of the shell is at 1
177. 4 5 or 6 the stiffness form is obtained The stiffness forms however can stiffen the response especially if the deformations are large and therefore should be used with care For high velocities the viscous forms are recommeded and for low velocities the stiffness forms are recommended For large deformations and nonregular solids option 3 or 5 is recommended QH Default hourglass coefficient QH Values of QH that exceed 15 may cause instabilities The recommended default applies to all options Remark 1 Hourglass coefficients and type can be set by part ID in HOURGLASS Section 7 42 CONTROL LS DYNA Version 960 CONTROL CONTROL_IMPLICIT_AUTO Purpose Define parameters for automatic time step control during implicit analysis Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IAUTO Automatic time step control flag EQ 0 constant time step size Default for standard implicit analysis EQ 1 automatically adjusted time step size Default for springback implicit analysis ITEOPT Optimum equilibrium iteration count per time step ITEWIN Allowable iteration window If iteration count is within ITEWIN iterations of ITEOPT step size will not be adjusted DTMIN Minimum allowable time step size Simulation stops with error termination if time step falls below DTMIN DTMAX Maximum allowable time step size LT 0 load curve gives DTMAX t each time point reached exactly see Figure 7 2 LS
178. 555555555555555 5 RIGIDWALL GEOMETRIC SPHERE MOTION 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 UUY UY Ur Ur UY Ur Ur UY Ur UY Define a rigid sphere with a radius of 8 centered at x y z 20 20 9 that moves in the negative z direction with a specified displacement given by a load curve load curve lcid 5 which prevents all nodes within a specified box from penetrating the sphere box number boxid 3 these nodes can slide on the sphere without friction RIGIDWALL GEOMEIRIC SPHERE MOTION 6 Del Zen DB De eem ene nee es Osee dala Pe 28 nsid nsidex 5 5 yt 20 0 20 0 6 radsph 8 0 5 lcid opt 5 1 DEFINE BOX 5 boxid xm 3 0 0 DEFINE CURVE lcid sidr 5 5 abscissa 0 0 0 0005 40 0 scla 20 0 0 0 sclo ordinate 0 0 15 0 yh 20 0 VZ 1 0 40 0 offa zh 210 10 offo 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 22 11 RIGIDWALL RIGIDWALL RIGIDWALL PLANAR OPTION OPTION OPTION Available options include BLANK ORTHO FINITE MOVING FORCES The ordering of the options in the input below must be observed but the ordering of the options on the command line is unimportant i e the ORTHO card is first the FINITE definition card below must preceed the MOVING definition card and the FORCES definition card should
179. 555555555555555555555555 5 BOUNDARY PRESCRIBED MOTION SET 55555555555555555555555555555555955555555555555555555555555555555555555555555555 5 set of nodes is given prescribed translational velocity in the x direction according to a specified vel time curve which is scaled BOUNDARY PRESCRIBED MOTION SET nsid dof vad lcid sf vid death 4 1 0 8 2 0 nsid 4 nodal set ID number requires a SET NODE option dof 1 motion is in x translation vad 0 motion prescribed is velocity lcid 8 velocity follows load curve 8 requires a DEFINE CURVE sf 2 0 velocity specified by load curve is scaled by 2 0 vid not used in this example death use default essentially no death time for the motion 5555555555555555555555555555555555555555555555555555555555555555555555555555555 5555555555555555555555555555555555555555555555555555555555555555555555555555555 BOUNDARY PRESCRIBED MOTION RIGID 5555555555555555555555555555555555555555555555555555555555555555555555555555555 gt rr Ur Xr Ur Ur UW Ur Ur Ur Ur Ur UY UY Ur UY UY UW Ur UW A rigid body is given a prescribed rotational displacement about the z axis according to a specified displacement time curve BOUNDARY PRESCRIBED MOTION RIGID death 14 prescribed motion is removed at 14 ms assuming time is in ms 5555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 5 pid dof vad lcid sf vid death 84 7 2 9 14 0 5 pid
180. 5555555555555555555555555555555 5 LS DYNA Version 960 19 23 LOAD LOAD LOAD_SEGMENT Purpose Apply the distributed pressure load over one triangular or quadrilateral segment defined by four nodes The pressure convention follows Figure 19 3 Card Format 1 2 3 4 5 6 7 8 ee p EN EHEN EN VARIABLE DESCRIPTION LCID Load curve ID see DEFINE_CURVE SF Load curve scale factor AT Arrival time for pressure or birth time of pressure NI Node Number N2 Node Number N3 Node Number Repeat N2 for two dimensional geometries N4 Node Number Repeat N2 for two dimensional geometries Remarks 1 If LCID is input as 1 then the Brode function is used to determine the pressure for the segments see LOAD_BRODE 2 If LCID is input as 2 then the ConWep function is used to determine the pressure for the segments see LOAD_BLAST 3 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled 4 The activation time AT is the time during the solution that the pressure begins to act Until this time the pressure is ignored The function value of the load curves will be evaluated at 19 24 LOAD LS DYNA Version 960 LOAD the offset time given by the difference of the solution time and AT i e solution time AT Relative displacements that occur prior to reaching AT are ignored Only relative displacements that occur after AT are prescribed 5 Triangul
181. 55555555555555555555555555555555 5 COMPONENT HYBRIDIII JOINT LEFT ANKLE 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 The damping coefficients applied to all three degrees of freedom of the left 6 ankle of dummy 7 are set to 2 5 All other characteristics of this joint remain set to the default value The dorsi plantar flexion angle is set to 20 degrees COMPONENT HYBRIDIII JOINT LEFT ANKLE ee a wereld Disk al ot Arg aes PAD ons Dee 5 did ql q2 q3 fric 7 0 20 0 0 0 5 cl alol blol ahil bhil qlol ghil 2 5 0 0 0 0 0 0 5 2 1 2 blo2 ahi2 bhi2 qlo2 2 2 5 0 0 0 0 0 0 5 2 5 alo3 blo3 ahi3 bhi3 qlo3 LS DYNA Version 960 4 13 COMPONENT COMPONENT 4 14 COMPONENT LS DYNA Version 960 CONSTRAINED CONSTRAINED The keyword CONSTRAINED provides a way of constraining degrees of freedom to move together in some way The keyword control cards in this section are defined in alphabetical order CONSTRAINED ADAPTIVITY CONSTRAINED EXTRA NODES OPTION CONSTRAINED GENERALIZED WELD OPTION CONSTRAINED GLOBAL CONSTRAINED INTERPOLATION CONSTRAINED JOINT OPTION CONSTRAINED JOINT STIFFNESS OPTION CONSTRAINED LAGRANGE IN SOLID CONSTRAINED LINEAR CONSTRAINED NODAL BODY CONSTRAINED NODE SET CONSTRAINED POINTS CONSTRAINED RIGID BODIES CONSTRAINED RIGID BODY STOPPERS CONSTRAINED RIVET CO
182. 55555555555555555555555555555555555555555 5 COMPONENT GEBOD JOINT LEFT SHOULDER 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 The damping coefficients applied to all three degrees of freedom of the left shoulder of dummy 7 are set to 2 5 All other characteristics of this joint 5 remain set to the default value COMPONENT GEBOD JOINT LEFT SHOULDER did Leu lc2 1c3 scf1 scf2 scf3 i 0 0 0 0 0 0 1 2 c3 neutl neut2 neut3 2 5 2 5 2 5 0 0 0 hisal losa2 hisa2 losa3 hisa3 0 0 0 0 0 0 unk1 unk2 unk3 0 0 0 5555555555555555555555555555555555555555555555555555555555555555555555555555555 4 Ur Ur uo Xx ur Xr Ur Ur Hh un mn 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 COMPONENT GEBOD JOINT WAIST 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 load curve 8 gives the torque versus rotation relationship for the 2nd DOF lateral flexion of the waist of dummy 7 Also the high stop angle of the 1st DOF forward flexion is set to 45 degrees All other characteristics 6 of this joint remain set to the default value COMPONENT GEBOD JOINT WAIST Giese Dan Lanta De Di ie ae eds RA an Dans i Oe ese lese 5 did 1 2 1c3 Scf1 Scf2 scf3 7 0 8 0 0 0 0 5 cl c2 c3 neutl neut2 neut3 0 0 0 0 0 0 5 losal hisal losa2 hisa2 losa3 hisa3 0 45 0 0 0 0 unk1 unk2 unk3 0 0 0 55
183. 5555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 5 43 CONSTRAINED CONSTRAINED CONSTRAINED_LAGRANGE_IN_SOLID Purpose Couple a Lagrangian mesh slave of shells solids or beams to the material points of an Eulerian mesh master This option may also be used to model rebar in concrete or tire cords in rubber The slave part or slave part set is coupled to the master part or master part set Note For RIGID slave PARTS a penalty coupling method must be used see option CTYPE below Card Format Card 1 1 2 3 Card 2 1 2 3 4 5 6 7 6 CTYPE DIREC 7 I 1 Card 3 1 2 3 4 5 6 7 8 5 44 CONSTRAINED LS DYNA Version 960 VARIABLE SLAVE MASTER SSTYP MSTYP NQUAD CTYPE DIREC MCOUP START END PFAC FRIC FRCMIN LS DYNA Version 960 CONSTRAINED DESCRIPTION Part part set ID or Segment set ID of slaves see PART SET PART or SET SEGMENT Part or part set ID of master solid elements see PART or SET PART Slave type 0 part set ID EQ 1 part ID EQ 2 segment set ID Master type 0 part set ID EQ 1 part ID Quadratue rule for coupling slaves to solids EQ 0 at nodes only EQ n use a rectangular grid of n n points EQ n at nodes and a rectangular grid of n n points Coupling type EQ 1 constrained acceleration EQ 2 constrained acceleration and velocity default EQ 3 constrained acceleration and
184. 5555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 19 25 LOAD LOAD LOAD_SEGMENT_SET Purpose Apply the distributed pressure load over each segment in a segment set The pressure convention follows Figure 19 3 Card Format 1 2 3 4 5 6 7 8 LLL I ILLI VARIABLE DESCRIPTION SSID Segment set ID see SET SEGMENT LCID Load curve ID see DEFINE CURVE SF Load curve scale factor AT Arrival time for pressure or birth time of pressure Remarks 1 If LCID is input as 1 then the Brode function is used to determine pressure for the segment set also see LOAD_BRODE 2 If LCID is input as 2 then the ConWep function is used to determine the pressure for the segments see LOAD_BLAST 3 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled 4 The activation time AT is the time during the solution that the pressure begins to act Until this time the pressure is ignored The function value of the load curves will be evaluated at the offset time given by the difference of the solution time and AT i e solution time AT Relative displacements that occur prior to reaching AT are ignored Only relative displacements that occur after AT are prescribed 19 26 LOAD LS DYNA Version 960 LOAD 2 Dimensional Definition for axisymmetic plane stress and plane strain geometries 2 t direction Fo
185. 555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 4 7 COMPONENT COMPONENT COMPONENT HYBRIDIII Purpose Define a HYBRID III dummy The motion of the dummy is governed by equations integrated within LS DYNA separately from the finite element model Joint characteristics stiffnesses damping friction etc are set internally and should give reasonable results however they may be altered using the COMPONENT HYBRIDIII JOINT command The dummy interacts with the finite element structure through contact interfaces Card Format Card 1 of 2 1 2 3 4 5 6 7 8 ee ee eee T ES EN EN VARIABLE DESCRIPTION DID Dummy ID A unique number must be specified SIZE Size of dummy EQ 1 5th percentile adult EQ 2 50th percemtile adult EQ 3 95th percentile adult UNITS System of units used in the finite element model EQ 1 Ibf sec2 in inch sec EQ 2 kg meter sec EQ 3 kgf sec2 mm mm sec EQ 4 metric ton mm sec EQ 5 kg mm msec DEFRM Deformability type EQ 1 all dummy segments entirely rigid EQ 2 deformable abdomen low density foam mat 57 EQ 3 deformable jacket low density foam mat 57 EQ 4 deformable headskin viscoelastic mat 6 EQ 5 deformable abdomen jacket EQ 6 deformable jacket headskin EQ 2 deformable abdomen headskin EQ 7 deformable abdomen jacket headskin VX VY VZ Initial velocity of the dummy in the global x
186. 5555555555555555555555555555555555555955 5 5 4 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED GENERALIZED WELD OPTION Then the following options are available SPOT FILLET BUTT CROSS FILLET COMBINED Purpose Define spot and fillet welds Coincident nodes are permitted if the local coordinate ID is defined For the spot weld a local coordinate ID is not required if the nodes are offset Failures can include both the plastic and brittle failures These can be used either independently or together Failure occurs when either criteria is met The welds may undergo large rotations since the equations of rigid body mechanics are used to update their motion Card 1 Format This card is required for all weld options 1 2 3 4 5 6 7 8 oe ee ee ee le VARIABLE DESCRIPTION NSID Nodal set ID see SET NODE OPTION CID Coordinate system ID for output of data in local system see DEFINE_ COORDINATE OPTION CID is not required for spotwelds if the nodes are not conincident FILTER Number of force vectors saved for filtering This option can eliminate spurious failures due to numerical force spikes however memory requirements are significant since 6 force components are stored with each vector LE 1 no filtering EQ n simple average of force components divided by n or the maximum number of force vectors that are stored for the time window option below LS DYNA Version 960 5 5 CONSTRAINED CONSTRAINED VARIA
187. 555955 5 5855 CONSTRAINED JOINT PLANAR 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 5 Define planar joint between two rigid bodies Nodes 91 and 94 are on rigid body 1 Nodes 21 and 150 are on rigid body 2 Nodes 91 and 21 must be coincident 5 These nodes define the origin of the joint plane 5 Nodes 94 and 150 must be coincident 5 accomplish this massless node 150 is artificially created at the same coordinates as node 94 and then added to rigid body 2 5 These nodes define the normal of the joint plane e g the vector from node 91 to 94 defines the planes normal CONSTRAINED JOINT PLANAR Sie oven lan Den Zu Denn Bann Be de Ban DE ni n2 n3 n4 n5 n6 rps 91 21 94 150 0 000E 00 NODE nid 2 tc rc 150 0 00 3 00 0 00 0 0 CONSTRAINED EXTRA NODES SET 5 pid nsid 2 6 5 32 CONSTRAINED LS DYNA Version 960 CONSTRAINED SET NODE LIST sid 6 nidi 150 request output for joint force data DATABASE JNTFORC dt cycl lcdt 0 0001 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5558 CONSTRAINED JOINT REVOLUTE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Create revolute joint between two rigid bodies The rigid
188. 7 INTRODUCTION INTRODUCTION SET A concept of grouping nodes elements materials etc in sets is employed throughout the LS DYNA3D input deck Sets of data entities can be used for output So called slave nodes used in contact definitions slaves segment sets master segment sets pressure segment sets and so on can also be defined The keyword SET can be defined in two ways 1 Option _LIST requires a list of entities eight entities per card and define as many cards as needed to define all the entities 2 Option _COLUMN where applicable requires an input of one entity per line along with up to four attribute values which are needed to specify for example failure criterion input that is needed for CONTACT_CONSTRAINT_NODES_TO_SURFACE TITLE In this section a title for the analysis is defined USER_INTERFACE This section provides a method to provide user control of some aspects of the contact algorithms including friction coefficients via user defined subroutines RESTART This section of the input is intended to allow the user to restart the simulation by providing a restart file and optionally a restart input defining changes to the model such as deleting contacts materials elements switching materials from rigid to deformable deformable to rigid etc RIGID_TO_DEFORMABLE This section switches rigid parts back to deformable in a restart to continue the event of a vehicle impacting the ground which may have been mo
189. 9 9 DATABASE DATABASE DATABASE_CROSS_SECTION_OPTION Options include PLANE SET Purpose Define a cross section for resultant forces written to ASCII file SECFORC For the PLANE option a set of two cards is required for each cross section Then a cutting plane has to be defined see Figure 9 1 If the SETS option is used just one card is needed In this latter case the forces in the elements belonging to the set are summed up to form the section forces Format 1 of 2 for the PLANE option 1 2 3 4 6 7 8 EHEN EHEN EN EIERN Format 2 of 2 for the PLANE option 1 2 3 4 5 6 7 8 XHEV YHEV ZHEV LENL LENM EN ITYPE mE me fe fe fe fete fe EEE 9 10 DATABASE LS DYNA Version 960 DATABASE Resultants are computed on this plane Origin of cutting plane Figure 9 1 Definition of cutting plane for automatic definition of interface for cross sectional forces The automatic definition does not check for springs and dampers in the section For best results the cutting plane should cleanly pass through the middle of the elements distributing them equally on either side LS DYNA Version 960 9 11 DATABASE DATABASE The set option requires that the equivalent of the automatically generated input via the cutting plane be identified manually and defined in sets All nodes in the cross section and their related elements that contribute to the cross sectional force resultants should be defined Format
190. 960 7 75 CONTROL CONTROL CONTROL_TERMINATION Purpose Stop the job Card Format 1 2 3 4 5 6 7 8 See VARIABLE DESCRIPTION ENDTIM Termination time Mandatory ENDCYC Termination cycle The termination cycle is optional and will be used if the specified cycle is reached before the termination time Cycle number is identical with the time step number DTMIN Reduction or scale factor for initial time step size to determine minimum time step TSMIN TSMIN DTSTART DTMIN where DTSTART is the initial step size determined by LS DYNA When TSMIN is reached LS DYNA3D terminates with a restart dump ENDENG Percent change in energy ratio for termination of calculation If undefined this option is inactive ENDMAS Percent change in the total mass for termination of calculation This option is relevant if and only if mass scaling is used to limit the minimum time step size see CONTROL_TIMESTEP variable name DT2MS Remarks 1 Termination by displacement may be defined in the TERMINATION section 2 If the erosion flag on CONTROL_TIMESTEP is set ERODE 1 then the shell elements and solid elements with time steps falling below TSMIN will be eroded 7 76 CONTROL LS DYNA Version 960 CONTROL CONTROL THERMAL NONLINEAR Purpose Set parameters for a nonlinear thermal or coupled structural thermal analysis The control card CONTROL SOLUTION is also required Card Form
191. 983 pseudo TENSOR geological model Sackett 1987 elastoplastic with fracture power law isotropic plasticity strain rate dependent plasticity rigid thermal orthotropic composite damage model Chang and Chang 1987a 1987b thermal orthotropic with 12 curves piecewise linear isotropic plasticity inviscid two invariant geologic cap Sandler and Rubin 1979 Simo et al 1988a 1988b orthotropic crushable model Mooney Rivlin rubber resultant plasticity force limited resultant formulation closed form update shell plasticity Frazer Nash rubber model laminated glass model fabric unified creep plasticity temperature and rate dependent plasticity elastic with viscosity anisotropic plasticity user defined crushable cellular foams Neilsen Morgan and Krieg 1987 urethane foam model with hystersis and some more foam and rubber models as well as many materials models for springs and dampers The hydrodynamic material models determine only the deviatoric stresses Pressure is determined by one of ten equations of state including LS DYNA linear polynomial Woodruff 1973 JWL high explosive Dobratz 1981 Sack Tuesday high explosive Woodruff 1973 Version 960 1 21 UNTRODUCTION INTRODUCTION Gruneisen Woodruff 1973 ratio of polynomials Woodruff 1973 linear polynomial with energy deposition ignition and growth of reaction in HE Lee and Tarver 1980 Cochran and Chan 1979
192. A Incompressible flow solver is available Structural coupling is not yet implemented Adaptive mesh coarsening can be done before the implicit springback calculation in metal forming applications Two dimensional adaptivity can be activated in both implicit and explicit calculations SMP version only An internally generated smooth load curve for metal forming tool motion can be activated with the keyword DEFINE CURVE SMOOTH Torsional forces can be carried through the deformable spot welds by using the contact type SPOTWELD WITH TORSION SMP version only with a high priority for the MPP version if this option proves to be stable Tie break automatic contact is now available via the CONTACT AUTOMATIC TIEBREAK options This option can be used for glued panels SMP only CONTACT RIGID SURFACE option is now available for modeling road surfaces SMP version only 1 8 INTRODUCTION LS DYNA Version 960 LS DYNA INTRODUCTION Fixed rigid walls PLANAR and PLANAR_FINITE are represented in the binary output file by a single shell element Interference fits can be modeled with the INTERFERENCE option in contact A layered shell theory is implemented for several constitutive models including the composite models to more accurately represent the shear stiffness of laminated shells Damage mechanics is available to smooth the post failure reduction of the resultant forces in the constitutive model MAT SPOTWELD DAMAGE
193. A Version 960 1 25 INTRODUCTION INTRODUCTION INTERFACE DEFINITIONS FOR COMPONENT ANALYSIS Interface definitions for component analyses are used to define surfaces nodal lines or nodal points INTERFACE_COMPONENTS for which the displacement and velocity time histories are saved at some user specified frequency CONTROL OUTPUT This data may then used to drive interfaces INTERFACE LINKING in subsequent analyses This capability is especially useful for studying the detailed response of a small member in a large structure For the first analysis the member of interest need only be discretized sufficiently that the displacements and velocities on its boundaries are reasonably accurate After the first analysis is completed the member can be finely discretized and interfaces defined to correspond with the first analysis Finally the second analysis is performed to obtain highly detailed information in the local region of interest When starting the analysis specify a name for the interface segment file using the Z parameter on the LS DYNA command line When starting the second analysis the name of the interface segment file created in the first run should be specified using the L parameter on the LS DYNA command line Following the above procedure multiple levels of sub modeling are easily accommodated The interface file may contain a multitude of interface definitions so that a single run of a full model can provide enough inter
194. AINED 2 tied nodes that can be coincident EN d Le y on no DE a L 4 tied nod Figure 5 3 Orientation of the local coordinate system and nodal ordering is shown for butt weld failure 5 12 CONSTRAINED LS DYNA Version 960 CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 CONSTRAINED GENERALIZED WELD BUTT 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 Weld two plates that butt up against each other at three nodal pair locations The nodal pairs are 32 33 34 35 and 36 37 This requires 3 separate CONSTRAINED GENERALIZED WELD BUIT definitions one for each nodal pair Each weld is to have a length L 10 thickness D 2 and a transverse length Lt 1 Failure is defined two ways Ductile failure if effective plastic strain exceeds 0 3 Brittle failure if the stress failure criteria exceeds 0 25 scale the brittle failure criteria by beta 0 9 Note beta lt 1 weakens weld beta gt 1 strengthens weld TUY UY Ur UY UY 4 4 UY XY UY Ur Ur UY UY CONSTRAINED GENERALIZED WELD BUTT nsid cid 21 tfail epsf sigy beta L D Lt 0 3 0 250 0 9 10 0 2 0 1 0 CONSTRAINED GENERALIZED WELD BUIT 5 nsid cid 23 5 tfail epsf sigy beta L D Lt 0 3 0 250 0 9 10 0 2 0 1 0 CONSTRAINED GENERALIZED WELD BUTT 5 nsid cid 25 tfail epsf sigy beta L D Lt 0 3 0 250 0 9 10
195. AINT FORCE TRANSDUCER PENALTY FORMING NODES TO SURFACE FORMING ONE WAY SURFACE TO SURFACE FORMING SURFACE TO SURFACE NODES TO SURFACE NODES TO SURFACE INTERFERENCE ONE WAY SURFACE TO SURFACE RIGID NODES TO RIGID BODY RIGID BODY ONE WAY TO RIGID BODY RIGID BODY TWO WAY TO RIGID BODY SINGLE EDGE SINGLE SURFACE SLIDING ONLY SLIDING ONLY PENALTY SURFACE TO SURFACE SURFACE TO SURFACE INTERFERENCE 6 33 CONTACT CONTACT STRUCTURED INPUT TYPE ID KEYWORD NAME 8 TIEBREAK_NODES_TO_SURFACE 9 TIEBREAK_SURFACE_TO_SURFACE 6 TIED_NODES_TO_SURFACE 06 TIED_NODES_TO_SURFACE_OFFSET 7 TIED_SHELL_EDGE_TO_SURFACE 7 SPOTWELD s7 SPOTWELD_WITH_TORSION 2 TIED_SURFACE_TO_SURFACE 02 TIED_SURFACE_TO_SURFACE_OFFSET 6 34 CONTACT LS DYNA Version 960 CONTACT CONTACT EXAMPLES 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONTACT NODES SURFACE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Make a simple contact that prevents the nodes in part 2 from 6 penetrating the segments in part 3 CONTACT NODES TO SURFACE Re deer c DP LR UO Dessen Dee c cO Ter Ders ssid msid sstyp mstyp sboxid mboxid spr mpr 2 3 3 3 fs fd de vc vac penchk bt dt sfs sfm sst mst sfst stmt fsf vsf sstype mstype 3 id s specified in ssid and msid are parts ssid 2 use slave nodes in part 2 msid 3 use master segments in part 3 Use d
196. ANG NEFSKE 25 For more information on these models the papers by Wang 1988 1995 and Nusholtz 1991 1996 are recommended LS DYNA Version 960 1 1 AIRBAG AIRBAG Card Format VARIABLE DESCRIPTION SID Set ID SIDTYP Set type EQ 0 segment 0 part IDs RBID Rigid body part ID for user defined activation subroutine EQ RBID Sensor subroutine flags initiates the inflator Load curves are offset by initiation time EQ 0 the control volume is active from time zero EQ RBID User sensor subroutine flags the start of the inflation Load curves are offset by initiation time See Appendix B VSCA Volume scale factor Vsca default 1 0 PSCA Pressure scale factor P ca default 1 0 VINI Initial filled volume Vini MWD Mass weighted damping factor D SPSF Stagnation pressure scale factor 0 lt y lt 1 Remarks The first card is necessary for all airbag options The sequence for the following cards which is different for each option is explained on the next pages Lumped parameter control volumes are a mechanism for determining volumes of closed surfaces and applying a pressure based on some thermodynamic relationships The volume is specified by a list of polygons similar to the pressure boundary condition cards or by specifying a 1 2 AIRBAG LS DYNA Version 960 AIRBAG material subset which represents shell elements which form the closed boundary All polygon normals must be oriented to face outwards from t
197. APPLICATIONS ESPECIALLY WHEN TRIANGULAR ELEMENTS ARE USED EQ 3 timestep size is based on the maximum eigenvalue This option is okay for structural applications where the material sound speed changes slowly The calculational cost to determine the maximum eigenvalue is significant but the increase in the time step size often allows for significantly shorter run times without using mass scaling Shell element minimum time step assignment TSLIMT When a shell controls the time step element material properties moduli not masses will be modified such that the time step does not fall below the assigned step size Applicable only to shell elements using material models MAT PLASTIC KINEMATIC MAT POWER LAW PLASTICITY MAT STRAIN RATE DEPENDENT PLASTICITY MAT PIECE WISE LINEAR PLASTICITY The DT2MS option below applies to all materials and element classes and may be preferred Time step size for mass scaled solutions DT2MS Positive values are for quasi static analyses or time history analyses where the inertial effects are insignificant Default 0 0 If negative TSSFAC IDT2MSI is the minimum time step size permitted and mass scaling is done if and only if it is necessary to meet the Courant time step size criterion This latter option can be used in transient analyses if the mass increases remain insignificant See CONTROL TERMINATION variable name ENDMAS Load curve ID that limits the maximum time step size optional This load
198. ARIABLE DESCRIPTION SID Set ID IDTYPE Set type EQ 0 Part set EQ 1 Part Remarks 1 multi material option defined here and void materials see VOID are incompatible and cannot be used together in the same run 2 2 ALE LS DYNA Version 960 ALE Example WATER GROUP 1 GROUP 2 GROUP 3 PART ID S 1 AND 2 PART ID 3 PART ID S 5 6 AND 7 The above example defines a mixture of three groups of materials oil water and air that is the number of ALE groupls NALEGP 3 The first group contains two parts materials part ID s 1 and 2 The second group contains one part material part ID 3 The third group contains three parts materials part ID s 5 6 and 7 LS DYNA Version 960 2 3 ALE ALE ALE REFERENCE SYSTEM CURVE Purpose This command is used to define a prescribed motion of an ALE mesh following 12 pre defined load curves The command must be combined with ALE_ REFERENCE SYSTEM GROUP Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 Card 3 1 2 3 4 5 6 7 8 2 4 ALE LS DYNA Version 960 ALE VARIABLE DESCRIPTION ID Curve set ID LC1 LC12 Load curve ID s Remark The velocity of a node at coordinate x y z is defined as ud dee dele te hy z j ifo fu fe is the value of load curve LC at time 1 etc LS DYNA Version 960 2 5 ALE ALE ALE REFERENCE SYSTEM GROUP Purpose This command is used to assi
199. ATABASE 2 202 eedem anne Ree TRE vid odes ache EL ege tek 1 1 APPENDIX J COMMANDS FOR TWO DIMENSIONAL 1 1 REZONING COMMANDS BY FUNCTION J 2 APPENDIX K RIGID BODY DUMMIES nennt iot Sr stad Se Er dupe edad yeaa dade vende essen fette dene K 1 APPENDIX L LS DYNA MPP USER GUIDE pos is iieie dae aret L 1 APPENDIX M IMPLICIT lu M 1 xiv LS DYNA Version 960 INTRODUCTION LS DYNA USER S MANUAL INTRODUCTION CHRONOLOGICAL HISTORY DYNAJ3D originated at the Lawrence Livermore National Laboratory Hallquist 1976 The early applications were primarily for the stress analysis of structures subjected to a variety of impact loading These applications required what was then significant computer resources and the need for a much faster version was immediately obvious Part of the speed problem was related to the inefficient implementation of the element technology which was further aggravated by the fact that supercomputers in 1976 were much slower than today s PC Furthermore the primitive sliding interface treatment could only treat logically regular interfaces that are uncommon in most finite element discretizations of complicated three dimensional geometries consequently defining a suitable mesh for handling contact was often very difficult The first version contained trusses membranes and a choice of solid elements The s
200. BLE DESCRIPTION WINDOW Time window for filtering This option requires the specification of the maximum number of steps which can occur within the filtering time window If the time step decreases too far then the filtering time window will be ignored and the simple average is used EQ 0 time window 1s not used NPR NFW number of individual nodal pairs in the cross fillet or combined general weld and general welds NPRT Print option in file RBDOUT EQ 0 default from Control Card 1s used EQ 1 data is printed EQ 2 data is not printed 5 6 CONSTRAINED LS DYNA Version 960 CONSTRAINED Additional Card required for the CONSTRAINED GENERALIZED WELD SPOT option Card 2 1 2 3 4 5 6 7 8 w fefefef et et ef EN VARIABLE DESCRIPTION TFAIL Failure time for constraint set tr default 1 E 20 EPSF Effective plastic strain at failure defines ductile failure SN Sn normal force at failure only for the brittle failure of spotwelds ss S shear force at failure only for the brittle failure of spotwelds N n exponent for normal force only for the brittle failure of spotwelds M m exponent for shear force only for the brittle failure of spotwelds Remarks Spotweld failure due to plastic straining occurs when the effective nodal plastic strain exceeds the input value Efa jj This option can model the tearing out of a spotweld from the sheet metal since the plasticity is in the material that surrounds the
201. CIT_EIGENVALUE Purpose Activate implicit eigenvalue analysis and define associated input parameters Card Format 1 2 3 4 5 6 7 8 CENTER LFLAG LFTEND RFLAG RHTEND EIGMTH SHFSCL VARIABLE DESCRIPTION NEIG Number of eigenvalues to extract This must be specified The other parameters below are optional CENTER Center frequency This option finds the nearest NEIG eigenvalues located about this value LFLAG Left end point finite flag EQ 0 left end point is infinity EQ 1 left end point is LFTEND LFTEND Left end point of interval Only used when LFLAG 1 RFLAG Right end point finite flag EQ 0 right end point is infinity EQ 1 right end point is RHTEND RHTEND Right end point of interval Only used when RFLAG 1 EIGMTH Eigenvalue extraction method EQ 1 Subspace iteration not recommended EQ 2 Block Shift and Invert Lanczos default SHFSCL Shift scale Generally not used but see explanation below Remarks To perform an eigenvalue analysis activate the implicit method by selecting IMFLAG 1 on CONTROL IMPLICIT GENERAL and indicate a nonzero value for NEIG above By default the lowest NEIG eigenvalues will be found If a nonzero center frequency is specified the NEIG eigenvalues nearest to CENTER will be found LS DYNA Version 960 7 47 CONTROL CONTROL It is strongly recommended that the default eigenvalue extraction method Block Shift and Invert Lanczos is used The Block Shift and Inver
202. Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 2 dii 5 bi o polo LS DYNA Version 960 3 39 BOUNDARY BOUNDARY Define the following card boundary radiation type 1 Card Format Card 2 of 2 1 2 3 4 5 6 7 8 Define the following card boundary radiation type 2 Card Format Card 2 of 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT N1 N2 Node ID s defining segment TYPE Radiation type EQ 1 Radiation boundary to environment default EQ 2 Radiation in enclosure The following two parameters are used for enclosure radiation definitions defined using the _SET option RAD_GRP Radiation enclosure group ID The segment sets from all radiation enclosure definitions with the same group ID are augmented to form a single enclosure definition If RAD_GRP is not specified or set to zero then the segments are placed in group zero All segments defined by the _SEGMENT option are placed in set zero 3 40 BOUNDARY LS DYNA Version 960 BOUNDARY VARIABLE DESCRIPTION FILE NO File number for view factor file FILE NO is added to viewfl to form the name of the file containing the view factors For example if FILE NO is specified as 22 then the view factors are read from viewfl 22 For radiation
203. Compression Figure 13 2 Pressure versus compaction curve Unloading occurs along the virgin loading curve until the excess compression surpasses After that the unloading follows a path between the completely crushed curve and the virgin loading curve Reloading will follow this curve back up to the virgin loading curve Once the excess compression exceeds 42 then all unloading will follow the completely crushed curve For unloading between and a partially crushed curve is determined by the relationship I u p u p where Hg P and the subscripts pc and cc refer to the partially crushed and completely crushed states respectively This is more readily understood in terms of the relative volume V 1 ru 13 28 EOS LS DYNA Version 960 EOS This representation suggests that for a fixed zu the partially crushed curve will separate linearly from the completely crushed curve as V increases to account for pore recovery in the material The bulk modulus K is determined to be the slope of the current curve times one plus the excess compression 1 u The slope for the partially crushed curve is obtained by differentiation as u ap 0 OP _ LH max odas Simplifying OP u K 1 Qi rn where Te 1 u 1 u 1 u The bulk sound speed is determined from the slope of the completely crushed curve at the
204. Coordinate system ID see DEFINE_COORDINATE_SYSTEM DOFX Insert 1 for translational constraint in local x direction DOFY Insert 1 for translational constraint in local y direction DOFZ Insert 1 for translational constraint in local z direction DOFRX Insert 1 for rotational constraint about local x axis DOFRY Insert 1 for rotational constraint about local y axis DOFRZ Insert 1 for rotational constraint about local z axis Remark Constraints are applied if a value of 1 is given for DOFxx A value of zero means no constraint No attempt should be made to apply SPCs to nodes belonging to rigid bodies see MAT_RIGID for application of rigid body constraints 3 44 BOUNDARY LS DYNA Version 960 BOUNDARY 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 BOUNDARY SPC NODE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Make boundary constraints for nodes 6 and 542 BOUNDARY SPC NODE SD ILS ge were De t Pueden 5 nid cid dofx dofy dofz dofrx dofry dofrz 6 0 1 HE 1 1 1 1 542 0 0 1 0 1 0 1 Node 6 is fixed in all six degrees of freedom no motion allowed Node 542 has a symmetry condition constraint in the x z plane 5 motion allowed for y translation 6 2 rotation 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS D
205. D Additional NPR Card Sets required for the COMBINED option Repeat cards 2 and 3 below NPR times Card 2 1 2 3 4 5 6 7 8 Card 3 VARIABLE DESCRIPTION TFAIL Failure time for constraint set tf default 1 E 20 EPSF Effective plastic strain at failure Epil defines ductile failure SIGY Of stress at failure for brittle failure BETA failure parameter for brittle failure L L length of fillet butt weld see Figure 5 2 and 5 3 W w width of flange see Figure 5 2 A a width of fillet weld see Figure 5 2 ALPHA weld angle see Figure 5 2 in degrees NODEA Node ID A in weld pair CROSS or COMBINED option only NODEB Node ID B in weld pair CROSS or COMBINED option only NCID Local coordinate system ID CROSS or COMBINED option only WTYPE Weld pair type GENERAL option only See Figure 5 5 EQ 0 fillet weld EQ 1 butt weld 5 16 CONSTRAINED LS DYNA Version 960 CONSTRAINED Figure 5 5 A combined weld is a mixture of fillet and butt welds LS DYNA Version 960 5 17 CONSTRAINED CONSTRAINED CONSTRAINED GLOBAL Purpose Define a global boundary constraint plane Card Format 1 2 3 4 5 6 7 8 foe fom fox fy e me fe fe fa EEE EN VARIABLE DESCRIPTION TC Translational Constraint EQ 1 constrained x translation EQ 2 constrained y translation EQ 3 constrained z translation EQ 4 constrained x and y translations EQ 5 constrained y and z translatio
206. D 1 N2 N3 4 a PID SID MID EOSID HGID A SECTION SHELL SID EEFORM SHRFE NIP PROPT QR ICOMP S 7 MAT_ELASTIC MID RO E PR DA DB 5 EOSID 7 HOURGLASS HGID Figure I 1 Organization of the keyword input LS DYNA Version 960 1 13 INTRODUCTION INTRODUCTION The input data following each keyword can be input in free format In the case of free format input the data is separated by commas i e NODE 10101 x y z 10201 x z ELEMENT SHELL 10201 pid n1 n2 n3 n4 10301 pid n1 n2 n3 n4 When using commas the formats must not be violated An 18 integer is limited to a maximum positive value of 99999999 and larger numbers having more than eight characters are unacceptable The format of the input can change from free to fixed anywhere in the input file The input is case insensitive and keywords can be given in either upper or lower case THE ASTERISKS PRECEDING EACH KEYWORD MUST IN COLUMN ONE To provide a better understanding behind the keyword philosophy and how the options work a brief review of some of the more important keywords is given below AIRBAG The geometric definition of airbags and the thermodynamic properties for the airbag inflator models can be made in this section This capability is not necessarily limited to the modeling of automotive airbags but it can also be used for many other applications such as tires and pneumatic dampers BOUNDARY
207. D Load curve ID defining mass flow rate versus pressure difference see DEFINE_CURVE If LCID is defined AREA SF and PID are ignored IFLOW Flow direction LT 0 One way flow from ABI to AB2 only EQ 0 Two way flow between ABl and AB2 GT 0 One way flow from AB2 to ABI only 1 40 AIRBAG LS DYNA Version 960 AIRBAG Remarks Mass flow rate and temperature load curves for the secondary chambers must be defined as null curves for example in the DEFINE_CURVE definitions give two points 0 0 0 0 and 10000 0 0 All input options are valid for the following airbag types AIRBAG SIMPLE AIRBAG MODEL AIRBAG WANG NEFSKE AIRBAG WANG NEFSKE JETTING AIRBAG WANG NEFSKE MULTIPLE JETTING AIRBAG HYBRID AIRBAG HYBRID JETTING The LCID defining mass flow rate vs pressure difference may additionally be used with AIRBAG LOAD CURVE AIRBAG LINEAR FLUID If the AREA SF and PID defined method is used to define the interaction then the airbags must contain the same gas i e Cp Cy and g must be the same The flow between bags is governed by formulas which are similar to those of Wang Nefske except that choked flow is currently ignored This will be added later LS DYNA Version 960 1 41 AIRBAG AIRBAG AIRBAG REFERENCE GEOMETRY OPTION OPTION Available options include BIRTH RDT The reference geometry becomes active at time BIRTH Until this time the input geometry is used to inflate the airbag Until the birth time is
208. E 4 and in double precision 1 E 8 The user can select one of 5 direct factorization methods and 6 iterative methods Solver options 4 default and 5 are updated versions of options 1 and 3 The updates include faster single cpu performance parallel implementation and the ability to select either MMD or Metis ordering see ORDER Options 1 and 3 are still included for backward compatibility with previous versions The direct linear equation solver from BCSLIB EXT Boeing s Extreme Mathematical Library is option 6 This option should be used whenever the factorization is too large to fit into memory It has extensive capabilities for out of core solution and can solve larger problems than any of the other direct factorization methods It is also faster than the older options 1 and 3 Select printing of the timing and storage information LPRINT 1 if you are comparing performance of linear equation solvers or if you are running out of memory for large models Minimum memory requirements for in core and out of 7 56 CONTROL LS DYNA Version 960 CONTROL core solution are printed This flag can also be toggled using sense switch lt ctrl c gt Iprint When using solver option 6 LPRINT 2 and 3 will cause increased printed output of statistics and performance information NEGEV Negative eigenvalues result from underconstrained models rigid body modes severely deformed elements or non physical material properties This flag all
209. E SET LOCAL keyword the coordinate system CID transformations will be skipped and the LOCAL option will have no effect LS DYNA Version 960 9 23 DATABASE DATABASE DATABASE_NODAL_FORCE_GROUP Purpose Define a nodal force group for output into ASCII file NODFOR and the binary file XTFILE See also DATABASE OPTION and DATABASE BINARY OPTION Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Nodal set ID see SET_NODE_OPTION CID Coordinate system ID for output of data in local system see DEFINE_ COORDINATE OPTION Remarks 1 nodal reaction forces in the global or local if CID is defined above x and z directions are printed into the NODFOR ascii file along with the external work which is a result of these reaction forces The resultant force vector found by summing the reaction forces over the nodes is also written into this file These forces can be a result of applied boundary forces such as nodal point forces and pressure boundary conditions body forces and contact interface forces In the absense of body forces interior nodes would always yield a null force resultant vector In general this option would be used for surface nodes 9 24 DATABASE LS DYNA Version 960 DATABASE DATABASE SPRING FORWARD Purpose Create spring forward nodal force file This option is to output resultant nodal force components of sheet metal at the end of the forming simulation into an ASCII file SPRING
210. E TCU EU FEX d 8 1 DAMPING GLOBALDL 5 B edt em Eo TR E TM IR 8 1 DAMPINGZBART MASS eite petra nici men ate etes 8 3 DAMPING PART STIFFNESS u ans renta REP eR ETE ee een 8 5 CONTROL REEXTIVE a items 8 7 DATABASE 0 a a EN X QU E EXE T VE S UE 9 1 DATABASE OPTION tete cct keeper ee Cete e ea P REEL ded Seg seeds Rete esed 9 2 iv LS DYNA Version 960 TABLE OF CONTENTS DATABASE BINARY OPTION it ere sn nannte 9 7 DATABASE CROSS SECTION 9 9 10 DATABASE EXTENT OPTION co ic 2 22 een sn 9 14 DATABASE FORMAT areas a re see ehr Rp anne es Due doute 9 21 DATABASE HISTORY OPTION iens tte et veo toe err trei 9 22 DATABASE NODAL FORCE 9 24 DATABASE SPRING 9 25 DATABASE SUPERPLASTIC 9 26 DATABASE TRACER ni nn het pr Bee iS dE UR eb ires 9 277 SDEFINE ss esse a u ei a ne 10 1 DEFINE BOX un ne 10 2 DEFINE BOX_ADAPTIVE uk tte nen 10 3 DEEINE BOX GOARSEN ditor ote Ba ai ote 10 5 DEFINE BOX DRAWBEAD ee en Pe ERR dpt repe DIE ERR DS 10 6 DEEINE COORDINXTE NODES skr eee veces ke Rs A 10 7 DEFINE COORDINATE 8 2 10 8 DEFINE COORDINATE 10 10 DEEINE CURVE
211. EFINE CURVE Remarks 1 Density versus depth curves are used to initialize hydrostatic pressure due to gravity acting on an overburden material The hydrostatic pressure acting at a material point at depth d is given by surface p ptd gdz where p is pressure d is the depth of the surface of the material to be initialized surface usually zero p z is the mass density at depth 2 and g is the acceleration of gravity This 19 14 LOAD LS DYNA Version 960 LOAD integral is evaluated for each integration point Depth may be measured along any of the global coordinate axes and the sign convention of the global coordinate system should be respected The sign convention of gravity also follows that of the global coordinate system For example if the positive z axis points up then gravitational acceleration should be input as a negative number 2 For this option there is a limit of 12 parts that can be defined by PSID unless all parts initialized 3 Depth is the ordinate of the curve and is input as a descending x y or z coordinate value Density is the abcissa of the curve and must vary increase with depth i e an infinite slope is not allowed LS DYNA Version 960 19 15 LOAD LOAD LOAD_HEAT_GENERATION_OPTION Available options are SET SOLID Purpose Define solid elements or solid element set with heat generation Card Format VARIABLE DESCRIPTION SID Solid element set ID or so
212. EQ 5 y and z rotational degrees of freedom EQ 6 z and x rotational degrees of freedom EQ 7 x y and z rotational degrees of freedom 3DOF This option does not apply to the spot weld beam type 9 Coordinate system option EQ 1 global coordinate system EQ 2 local coordinate system default Based on beam type Type EQ 1 beam thickness s direction at node 1 Type EQ 2 area Type EQ 3 area Type EQ 4 beam thickness s direction at node 1 Type EQ 5 beam thickness s direction at node 1 Type EQ 6 volume Type EQ 7 beam thickness s direction at node 1 Type EQ 8 beam thickness s direction at node 1 Type EQ 9 beam thickness s direction at node 1 Based on beam type Type EQ 1 beam thickness s direction at node 2 Type EQ 2 1 Type EQ 3 not used Type EQ 4 beam thickness s direction at node 2 Type EQ 5 beam thickness s direction at node 2 Type EQ 6 geometric inertia Type EQ 6 volume Type EQ 7 beam thickness s direction at node 2 Type EQ 8 beam thickness s direction at node 2 Type EQ 9 beam thickness s direction at node 2 LS DYNA Version 960 ELEMENT VARIABLE DESCRIPTION PARM3 Based on beam type Type EQ 1 beam thickness t direction at node 1 Type EQ 2 Tt Type EQ 3 not used Type EQ 4 beam thickness t direction at node 1 Type EQ 5 beam thickness t direction at node 1 Type EQ 6 local coordinate ID Type EQ 7 not used Type EQ 8 not used Type EQ 9 beam thickness t direction at node 1
213. ERENCE SYSTEM CURVE EQ 4 Automatic mesh motion following mass weighted average velocity in ALE mesh EQ 5 Automatic mesh motion following coordinate system defined by three user defined nodes see REFERENCE SYSEM NODE EQ 7 Automatic mesh expansion in order to enclose up to twelve user defined nodes see REFERENCE SYSEM NODE IDI ID7 ID of node or curve group PRTYPE 3 5 or 7 Remark At time T2 the reference system type is switched from TYPE2 to TYPE3 etc 2 12 ALB LS DYNA Version 960 ALE ALE SMOOTHING Purpose This smoothing constraint keeps a node at its initial parametric location along a line between two other nodes This constraint is active during each mesh smoothing operation Card Format 1 2 3 4 5 6 7 8 ee ee EEE HE EEE EU are di ii fom fo fo VARIABLE DESCRIPTION SNID Slave node ID see Figure 2 1 MNID1 First master node ID MNID2 Second master node ID IPRE EQ 0 smoothing constraints are performed after mesh relaxation EQ 1 smoothing constraints are performed before mesh relaxation XCO x coordinate of constraint vector YCO y coordinate of constraint vector ZCO z coordinate of constraint vector LS DYNA Version 960 2 13 ALE ALE Remark Abritrary Lagrangian Eulerian meshes are defined via the choice of the element type and the CONTROL ALE card This can only be used with solid elements 1st master node slave node 2nd master node Fi
214. ET to the rigid wall are included as slave nodes for the rigid wall If options NSID NSIDEX or BOXID are active then only the subset of nodes activated by these options are checked to see if they are within the offset distance LS DYNA Version 960 22 13 RIGIDWALL RIGIDWALL Card 2 Required Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XT x coordinate of tail of any outward drawn normal vector n originating on wall tail and terminating in space head see Figure 22 3 YT y coordinate of tail of normal vector n ZT Z coordinate of tail of normal vector n XH x coordinate of head of normal vector n YH y coordinate of head of normal vector n ZH Z coordinate of head of normal vector n FRIC Interface friction EQ 0 0 frictionless sliding after contact EQ 1 0 no sliding after contact 0 lt FRIC lt 1 Coulomb friction coefficient EQ 2 0 node is welded after contact with frictionless sliding Welding occurs if and only if the normal value of the impact velocity exceeds the critical value specified by WVEL EQ 3 0 node is welded after contact with no sliding Welding occurs if and only if the normal value of the impact velocity exceeds the critical value specified by WVEL WVEL Critical normal velocity at which nodes weld to wall FRIC 2 or 3 22 14 RIGIDWALL LS DYNA Version 960 RIGIDWALL Optional Cards A and B Required if ORTHO is specified after the keyword See Figure 23 2 for the definition of
215. EXTENT_BINARY D3PLOT Dt for complete output states See also DATABASE_EXTENT_BINARY D3THDT Dt for time history data of element subsets See DATABASE HISTORY RUNRSF Binary output restart file Define output frequency in cycles INTFOR Dt for output of contact interface data file name must be given on the execution line using S Also see CONTACT variables mpr and spr XTFILE Flag to specify output of extra time history data to XTFILE at same time as D3THDT file The following card is left blank for this option D3CRCK Dt for output of crack data file for the Winfrith concrete model file name must be given on the execution line using q This file can be used with the D3PLOT file to show crack formation of the deformed concrete materials The D3DUMP and the RUNRSF options create complete databases which are necessary for restarts see RESTART When RUNRSF is specified the same file is overwritten after each interval When D3DUMP is specified a new restart file is created after each interval When D3DUMP is specified a new restart file is created after each interval thus a family of files is created numbered sequentially DBDUMPOI D3DUMPO2 etc The default file names are RUNRSF and D3DUMP unless other names are specified on the execution line see the INTRODUCTION EXECUTION SYNTAX Since all data held in memory is written into the restart files these files can be quite large and care should be taken with the D3DUMP files not t
216. FINE 5 lcid sidr scla sclo offa offo 1 abscissa ordinate 0 0 0 0 10 0 100 0 20 0 0 0 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 LOAD 19 21 LOAD LOAD LOAD_RIGID_BODY Purpose Apply a concentrated nodal force to a rigid body The force is applied at the center of mass or a moment is applied around a global axis As an option local axes can be defined for force or moment directions Card Format VARIABLE DESCRIPTION PID Part ID of the rigid body see PART_OPTION DOF Applicable degrees of freedom EQ 1 x direction of load action EQ 2 y direction of load action EQ 3 z direction of load action EQ 4 follower force see remark 2 on next page EQ 5 moment about the x axis EQ 6 moment about the y axis EQ 7 moment about the z axis EQ 8 follower moment see remark 2 LCID Load curve ID see DEFINE_CURVE 0 force as a function of time LT 0 force as a function of the absolute value of the rigid body displacement SF Load curve scale factor CID Coordinate system ID 1 Node 1 ID Only necessary if DOF EQ 4 or 8 see remark 2 on next page 19 22 LOAD LS DYNA Version 960 LOAD VARIABLE DESCRIPTION M2 Node 2 ID Only necessary if DOF EQ 4 or 8 see remark 2 M3 Node 3 ID Only necessary if DOF EQ 4 or 8 see remark 2 Remarks 1 The global coordinate system is the default The local coordinat
217. FLD TRANSVERSELY ANISOTROPIC 2 153 MAT NONLINEAR 155 X LS DYNA Version 960 TABLE OF CONTENTS MAT USER DEFINED MATERIAL 5 22 159 MAT BAMMAN Pep e ep ee ee ep ea 162 MAT BAMMAN teer erret etre D rte Led oda Pee tae esee 167 MAT CLOSED CEEE FOAM tecti BR ee y o e eee he 170 MAT ENHANCED COMPOSITE 172 MAT EOW DENSITY EOAM 2 222 RR nie 179 MAT LAMINATED COMPOSITE 2 183 MAT COMPOSITE FAILURE OPTION MODEL IH 189 MAT ELASTIC WITH VISCOSTEY asses 5 tt res Re at 193 MAT KELVIN MAXWELL VISCOELASTIC nee 196 MAT VISCOUS FOAM 3 p weni aan iss 198 NATCGRUSHABEE EQ AM cett teen Re 200 MAT RATE SENSITIVE POWERLAW PLASTICITY 202 MAT MODIFIED ZERILLI 5 204 MAT_CONCRETE DAMAGE neun eene et rd e eg este 207 MAT LOW DENSITY VISCOUS 211 MAT BILKHU DUBOIS FOAM cess EAR ibs ab an 215 MAT GENERAL VISCOELASTIC 5nd vce ucts De eve e una 217 MAT HYPERELASTIC RUBBER In eret een 220 MAT OGDEN RUBBER 3 2 2 2 REI eret EHE SSH en 224
218. FORMABLE_TO_RIGID DEFORMABLE TO RIGID VARIABLE PID XC YC ZC IXX IXY IYZ LZ DESCRIPTION Part ID see PART x coordinate of center of mass y coordinate of center of mass Z coordinate of center of mass Translational mass Ix xx component of inertia tensor 11 8 DEFORMABLE TO RIGID LS DYNA Version 960 ELEMENT ELEMENT The element cards in this section are defined in alphabetical order ELEMENT_BEAM_ OPTION ELEMENT_DIRECT_MATRIX_INPUT ELEMENT_DISCRETE ELEMENT_INERTIA ELEMENT_MASS ELEMENT_SEATBELT ELEMENT_SEATBELT_ACCELEROMETER ELEMENT_SEATBELT_PRETENSIONER ELEMENT_SEATBELT_RETRACTOR ELEMENT_SEATBELT_SENSOR ELEMENT_SEATBELT_SLIPRING ELEMENT_SHELL_ OPTION ELEMENT_SOLID_ OPTION ELEMENT_SPH ELEMENT_TRIM ELEMENT_TSHELL The ordering of the element cards in the input file is competely arbitrary An arbitrary number of element blocks can be defined preceeded by akeyword control card LS DYNA Version 960 12 1 ELEMENT ELEMENT ELEMENT BEAM OPTION Available options include BLANK THICKNESS PID Purpose Define two node elements including 3D beams trusses 2D axisymmetric shells and 2D plane strain beam elements The type of the element and its formulation is specified through the part ID see PART and the section ID see SECTION Two alternative methods are available for defining the cross sectional property data The
219. FORWARD for spring forward and die corrective simulations Card Format Cards 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IFLAG Output type EQ 0 off EQ 1 output element nodal force vector for deformable nodes EQ 2 output element nodal force vector for materials subset for NIKE3D interface file LS DYNA Version 960 9 25 DATABASE DATABASE DATABASE SUPERPLASTIC FORMING Purpose Specify the output intervals to the superplastic forming output files The option LOAD _ SUPERPLASTIC FORMING must be active Card Format Cards 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION 99 DTOUT Output time interval for output to pressure curvel and curve2 files The pressure file contains general information from the analysis and the files curvel and curve2 contain pressure versus time from phases 1 and 2 of the analysis The pressure file may be plotted in Phase 3 of LS TAURUS using the SUPERPL option 9 26 DATABASE LS DYNA Version 960 DATABASE DATABASE_TRACER Purpose Tracer particles will save a history of either a material point or a spatial point into an ASCH file TRHIST This history includes positions velocities and stress components The option DATABASE TRHIST must be active Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TIME Start time for tracer particle TRACK Tracking option EQ 0 particle follows material EQ 1 particle is fixed in space
220. Finite elastic strain isotropic plasticity model is available for solid elements MAT_ FINITE_ELASTIC_STRAIN_PLASTICITY A shape memory alloy material is available MAT_SHAPE MEMORY Reference geometry for material MAT_MODIFIED_HONEYCOMB can be set at arbitrary relative volumes or when the time step size reaches a limiting value This option is now available for all element types including the fully integrated solid element Non orthogonal material axes are available in the airbag fabric model See MAT_ FABRIC Other new constitutive models include for the beam elements MAT_MODIFIED_FORCE_LIMITED MAT_SEISMIC_BEAM MAT_CONCRETE_BEAM for shell and solid elements MAT_ELASTIC_VISCOPLASTIC_THERMAL for the shell elements MAT_GURSON MAT_GEPLASTIC_SRATE2000 MAT_ELASTIC_VISCOPLASTIC_THERMAL MAT_COMPOSITE_LA YUP MAT_COMPOSITE_LA YUP MAT_COMPOSITE_DIRECT for the solid elements MAT_JOHNSON_HOLMQUIST_CERAMICS MAT_JOHNSON_HOLMQUIST_CONCRETE MAT_INV_HYPERBOLIC_SIN MAT_UNIFIED_CREEP MAT_SOIL_BRICK MAT_DRUCKER_PRAGER MAT_RC_SHEAR_WALL and for all element options a very fast and efficient version of the Johnson Cook plasticity model is available MAT_SIMPLIFIED_JOHNSON_COOK A fully integrated version of the type 16 shell element is available for the resultant constitutive models A nonlocal failure theory is implemented for predicting failure in metallic materials The keyword MAT_NONLOCAL activates this option for a subset of elas
221. Format 1 2 3 4 5 6 7 8 zen uid VARIABLE DESCRIPTION XC x component axis vector of axis of rotation YC y component axis vector of axis of rotation ZC z component axis vector of axis of rotation NSIDI Node set ID for first boundary plane side 1 see Figure 3 1 NSID2 Node set ID for second boundary plane side 2 see Figure 3 1 Each boundary node in this boundary plane is constrained to its corresponding node in the first node set Node sets NSID1 and NSID2 must contain the same number of nodal points Care has to be taken that the nodes in both node sets have a location which if given in cylindrical coordinates all differ by the same angle Remark Only globally defined axes of rotation are possible 3 6 BOUNDARY LS DYNA Version 960 BOUNDARY Conformable Interface Segment Figure 3 1 With cyclic symmetry only one segment is modeled LS DYNA Version 960 3 7 BOUNDARY BOUNDARY BOUNDARY ELEMENT METHOD OPTION Available options are CONTROL FLOW NEIGHBOR SYMMETRY WAKE Purpose Define input parameters for boundary element method analysis of incompressible fluid dynamics or fluid structure interaction problems The boundary element method BEM can be used to compute the steady state or transient fluid flow about a rigid or deformable body The theory which underlies the method see the LS DYNA Theoretical Manual is restricted to inviscid incompressible
222. GHT ELBOW LEFT WRIST RIGHT WRIST LEFT HIP RIGHT HIP LEFT KNEE RIGHT KNEE LEFT ANKLE RIGHT ANKLE RIBCAGE Card 1 Required 1 2 3 4 5 6 7 8 4 10 COMPONENT LS DYNA Version 960 COMPONENT Card 2 Required 1 2 3 4 5 6 7 8 w fet ef ef ef ef ete Card 3 Required Left blank if joint has only one degree of freedom 1 2 3 4 5 6 7 8 fet et et et ep ef ld Card 4 Required Left blank if the joint has only two degrees of freedom 1 2 3 4 5 6 7 8 w fe fete fe fe fete LS DYNA Version 960 4 11 COMPONENT COMPONENT VARIABLE DESCRIPTION DID Dummy ID see HYBRIDIII Qi Initial value of the joint s i th degree of freedom Units of degrees are defined for rotational DOF See Appendix K for a listing of the applicable DOF FRIC Friction load on the joint Ci Linear viscous damping coefficient applied to the i th DOF of the joint ALOi Linear coefficient for the low regime spring of the joint s i th DOF BLOi Cubic coeffient for the low regime spring of the joint s i th DOF Linear for the high regime spring of the joint s i th DOF BHIi Cubic coeffient for the high regime spring of the joint s i th DOF QLOi Value for which the low regime spring definition becomes active QHIi Value for which the high regime spring definition becomes active 4 12 COMPONENT LS DYNA Version 960 COMPONENT 5 555555555555555555555555555555555555555555555555
223. IALIZATION OPTION This keyword allows a full deck restart to be performed in LS DYNA For a full deck restart a complete input deck has to be included in the restart deck The stress initialization feature allows all or a number of parts to be initialized on restart The options that are available with this kewyord are BLANK DISCRETE SEATBELT LS DYNA Version 960 29 31 RESTART RESTART STRESS INITIALIZATION If this card is specified without further input then all parts in the new analysis are initialized from the corresponding part of the old analysis Further all seatbelt and discrete parts are initialized If only a subset of parts are to be initialized in the new analysis then define as many of the following cards as necessary Termination of this input is when the next card is read Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PIDO Old part ID see PART PIDN New part ID see PART EQ 0 New part ID is the same as the old part ID Remarks If one or more of the above cards are defined then discrete and and seatbelt elements will not be initialized unless the additional option cards STRESS INITIALIZATION DISCRETE and STRESS INITIALIZATION SEATBELT are defined 29 32 RESTART LS DYNA Version 960 RESTART STRESS INITIALIZATION DISCRETE Initialize all discrete parts from the old parts No further input is required with this card This card is not required if STRESS INITIALIZA
224. ID only The REPOSITION option applies to deformable materials and is used to reposition deformable materials attached to rigid dummy components whose motion is controlled by either CAL3D or MADYMO At the beginning of the calculation each component controlled by CAL3D MADYMO is automatically repositioned to be consistent with the CAL3D MADYMO input However deformable materials attached to these component will not be repositioned unless this option is used The CONTACT option allows part based contact parameters to be used with the automatic contact types a3 4 a5 a10 13 a13 15 and 26 that is CONTACT AUTOMATIC SURFACE TO SURFACE CONTACT SINGLE SURFACE CONTACT AUTOMATIC NODES TO SURFACE CONTACT AUTOMATIC ONE WAY SURFACE TO SURFACE 21 2 PART LS DYNA Version 960 PART CONTACT_AUTOMATIC_SINGLE_SURFACE CONTACT AIRBAG SINGLE SURFACE CONTACT ERODING SINGLE SURFACE CONTACT AUTOMATIC GENERAL The default values to use for these contact parameters can be specified on the CONTACT input setction card The PRINT option allows user control over whether output data is written into the ASCII files MATSUM and RBDOUT See DATABASE ASCII Card Format Card 1 4 2 14 fm es fs Card 2 1 2 3 4 5 6 7 8 dini uH idi LS DYNA Version 960 21 3 PART PART Additional Cards are required for the INERTIA option See remarks 3 and 4 Card 3 1 2 3 4 Card 4 1 2 3 4 5 6 7 8
225. INATION ncycle Overrides ENDCYC defined in CONTROL_TERMINATION In order to avoid undesirable or confusing results each LS DYNA run should be performed in a separate directory If rerunning a job in the same directory old files should first be removed or renamed to avoid confusion since the possibility exists that the binary database may contain results from both the old and new run By including KEYWORD anywhere on the execute line or instead if KEYWORD is the first card in the input file the keyword formats are expected otherwise the older structured input file will be expected To run a coupled thermal analysis the command COUPLE must be in the execute line A thermal only analysis may be run by including the word THERMAL in the execution line The INIT sw1 can be used instead command on the execution line causes the calculation to run just one cycle followed by termination with a full restart file No editing of the input deck is required The calculation can then be restarted with or without any additional input Sometimes this option can be used to reduce the memory on restart if the required memory is given on the execution line and is specified too large in the beginning when the amount of required memory is unknown Generally this option would be used at the beginning of a new calculation If the word MEMORY is found anywhere on the execution line and if it is not set via nwds LS DYNA3D will give the default size of memor
226. ING DISCRETE NODE OPTION Options include NODE SET Purpose Define an interface for linking discrete nodes to an interface file This link applies to spring and beam elements only Card Format VARIABLE DESCRIPTION NID Node ID or Node set ID to be moved by interface file see NODE or SET NODE IFID Interface ID in interface file 18 2 INTERFACE LS DYNA Version 960 INTERFACE INTERFACE_LINKING_SEGMENT Purpose Define an interface for linking segments to an interface file for the second analysis using L isf2 on the execution command line This applies segments on shell and solid elements Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set to be moved by interface file IFID Interface ID in interface file LS DYNA Version 960 18 3 INTERFACE INTERFACE INTERFACE_LINKING_ EDGE Purpose Define an interface for linking a series of nodes in shell structure to an interface file for the second analysis using L isf2 on the execution command line This link applies segments on shell elements only Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Node set ID to be moved by interface file IFID Interface ID in interface file 18 4 INTERFACE LS DYNA Version 960 INTERFACE INTERFACE_JOY Purpose Define an interface for linking calculations by moving a nodal interface Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Nodal set ID see SET NODE
227. INITIAL_STRESS_SOLID Purpose Initialize stresses and plastic strains for solid elements Define as many solid elements in this section as desired The input is assumed to terminate when a new keyword is detected If eight points are defined for 1 point LS DYNA solid elements the average value will be taken Card Format Card 1 1 2 3 4 5 6 7 8 Define NINT cards below one per integration point NINT should be either 1 or 8 If eight Gauss integration points are specified they should be ordered such that their parametric coordinates are located at 22 523 2 3 C 3 3 ouam 3 3 37373 37373 3 3 3 2 3 3 E 3 3 3 3 respectively Card 2 1 2 3 4 5 6 SIGII SIG22 SIG33 51612 51623 SIG31 7 8 w of 16 14 INITIAL LS DYNA Version 960 VARIABLE EID NINT SIGIJ EPS LS DYNA Version 960 DESCRIPTION INITIAL Element ID Number of integration points either 1 or 8 Define the IJ stress component Effective plastic strain 16 15 INITIAL INITIAL INITIAL_TEMPERATURE_OPTION Available options are NODE SET Purpose Define initial nodal point temperatures using nodal set ID s or node numbers These initial temperatures are used in a thermal only analysis or a coupled thermal structural analysis See also CONTROL THERMAL SOLVER CONTROL THERMAL TIMESTEP and CONTROL THERMAL NONLINEAR For thermal loading in a structural
228. ITIAL_VELOCITY_NODE 5 NODF eq Ui ROTi Ai Vi LabD eq lcid LabF eq val BOUNDARY_PRESCRIBED_ MOTION_NODE 5 NDOF eq Fi LabF eq lcid LOAD_NODE_POINT 5 SFE ELEM LKEY Lab KEY R5 0 5 LKEY eq lcid Lab eq pressure LOAD SEGMENT Remarks Is Supported keywords as described in the SASI ANSYS Manual chapter on Exporting a Finite Element Model 22 Solid elements and shell elements cannot have the same R value in reference to ANSYS keywords 3 Supported element types include 63 eq shells 45 eq solids 73 eq solids 4 eq beams 16 eq pipes and 21 eq lumped masses 27 2 TRANSLATE LS DYNA Version 960 TRANSLATE TRANSLATE_IDEAS_ OPTION Available options include lt BLANK gt MASTER Purpose Provide a convenient route to read in files created by IDEAS SUPERTAB as part of the LS DYNA keyword input This keyword can appear more than once in the input It is a direct interface to IDEAS universal files Card Format VARIABLE DESCRIPTION FILE Filename of the IDEAS universal file The following table lists supported IDEAS keywords Version SDRC IDEAS Universal File LS DYNA Keyword All N Type NODE Val1 Val2 Val3 NODE All EN Type 11 12 13 14 15 16 17 18 ELEMENT 5 781 NODE MASTER 2411 NODE 5 780 ELEMENT MASTER 2412 ELEMENT 5 773 MAT_ELASTIC 5 772 PART amp SECTION 6 788 PART amp SECTION LS DYNA Version 960 27 3 TRANSLATE TRANSLATE Version MASTER 5 MASTER MASTER
229. LINEAR ELASTIC DISCRETE 0000 395 MAT NONLINEAR PLASTIC DISCRETE 2 2 20 2 398 MAT SID DAMPER DISCRETE BEAM 403 MAT HYDRAULIC GAS DAMPER DISCRETE 407 MAT CABLE DISCRETE BEAM i ict Ier eret eee 409 MAT ELASTIC SPRING DISCRETE 411 xii LS DYNA Version 960 TABLE OF CONTENTS MAT ELASTIC 6DOF SPRING DISCRETE BEAM HH 413 MAT INELASTIC SPRING DISCRETE BEAM 2 2 2000 414 MAT INELASTIC 6DOF SPRING DISCRETE BEAM 2 417 MAT SPRING ELASTIG 222 2 25 22 eere b tt einst ole onte s 418 VISCOUS 20 HER EEEE EEDA EESTIS PENERE 419 MAT SPRING EELASTOBELASTIE u HR 420 MAT SPRING NONLINEAR 5 421 MAT DAMPER 5 8 2 422 MAT SPRING GENERAL 423 MAT SPRING MAX WEBI re ai RER Zen IN 425 MAT SPRING _INELAS TIC EE nike 426 MAT SPRING TRILINEAR 427 MAT SPRING SQUAT 5 428 MAT SPRING 2 22 22 e ee Eee orn ea ERE Er M ERE I seated 429
230. LS DYNA KEYWORD USER S MANUAL VOLUME I March 2001 Version 960 Copyright 1992 2001 LIVERMORE SOFTWARE TECHNOLOGY CORPORATION All Rights Reserved Mailing Address Livermore Software Technology Corporation 2876 Waverley Way Livermore California 94550 1740 Support Address Livermore Software Technology Corporation 7374 Las Positas Road Livermore California 94550 TEL 925 449 2500 FAX 925 449 2507 EMAIL sales lstc com Copyright 1992 2001 by Livermore Software Technology Corporation All Rights Reserved TABLE OF CONTENTS TABLE OF CONTENTS Volume I 222 222 2 5 5 4 6 nee 1 1 CHRONOLOGICAL HISTORY wise 32 2 22 er eee ede vae 1 1 DESCRIPTION OF KEYWORD INPUT ccccceeseeeseeeseeeneeennennnennnnnnnnnnen een nenn 1 12 MATERIAL IR Des 1 21 SPATIAL DISCRETIZATION ee nennen 1 22 CONTACT IMPACT 00 00000000 1 25 INTERFACE DEFINITIONS FOR COMPONENT 1 26 CAPACITY a a ee ok Ah inet A 1 26 SENSE SWEECH CONTROLS cb nieto eet See Mee A Rees 1 26 PREGISIONs X HH Re N 1 27 EXBECUTION SYN DAX 32 22 22 as nl en ee gehe 1 27 RESTART ANALYSIS xt oett e Reo anal te ec etd EON que 1 31 VDAZIGES DATADBJASES dt to
231. LUMAS manual and strnam in the AUGMAT manual The execution line in the first step is LS DYNA Version 960 3 51 BOUNDARY BOUNDARY LS DYNA memory nwds i inputfilename gt outputfilename where inputfilename is the LS DYNA input file In the second step the DAA fluid mass matrix is created through execution of the USA FLUMAS processor FLUMAS m nwds lt flumasinputfilename gt flumasoutputfilename In the third step the modified augmented DAA equations for the coupled problem are calculated and saved through execution of the USA AUGMAT processor AUGMAT m nwds lt augmatinputfilename gt augmatoutputfilename This step is repeated whenever one wishes to change DAA formulations In the fourth step the actual coupled time integration is conducted using the execution line LS DYNA memory nwds r d3dump usa usainputfilename gt outputfilename The input files flumasinputfilename augmatinputfilename and usainputfilename are prepared in accordance with the USA code documentation It is advisable when running coupled problems to check the ASCII output files to ensure that each run completed normally 3 52 BOUNDARY LS DYNA Version 960 COMPONENT COMPONENT The keyword COMPONENT provides a way of incorporating specialized components and features The keyword control cards in this section are defined in alphabetical order COMPONENT_GEBOD_OPTION COMPONENT_GEBOD_JOINT_OPTION COMPONENT HYBRIDIII
232. M are used appropriately DTBEM is used to increase the time increment between calls to the BEM routines This can usually be done with little loss in accuracy since the characteristic times of the structural dynamics and the fluid flow can differ by several orders of magnitude The characteristic time of the structural dynamics in LS DYNA is given by the size of the smallest structural element divided by the speed of sound of its material For a typical problem this characteristic time might be equal to 1 microsecond Since the fluid in the boundary element method is assumed to be incompressible infinite speed of sound the characteristic time of the fluid flow is given by the streamwise length of the smallest surface in the flow divided by the fluid velocity For a typical problem this characteristic time might be equal to 10 milliseconds For this example DTBEM might be set to 1 millisecond with little loss of accuracy Thus for this example the boundary element method would be called only once for every 1000 LS DYNA iterations saving an enormous amount of computer time IUPBEM is used to increase the number of times the BEM routines are called before the matrix of influence coefficients is recomputed and factored these are time consuming procedures If the motion of the body is entirely rigid body motion there is no need to ever recompute and factor the matrix of influence coefficients after initialization and the execution time of the BEM can
233. MENT BEAM ELEMENT SHELL ELEMENT SOLID ELEMENT TSHELL pose Delete contact surfaces parts or elements by a list of IDs There are two contact algorithms for two dimensional problems the line to line contact and the automatic contact defined by part ID s Each use their own numbering For CONTACT CONTACT 2DAUTO ENTITY or PART option Card Format VARIABLE DESCRIPTION IDI Contact ID Part ID For DELETE CONTACT a negative ID implies that the absoulute value gives the contact surface which is to be activated 29 24 RESTART LS DYNA Version 960 RESTART For the four ELEMENT options Termination of input is when the next card is read Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ESID Element set ID see SET_SOLID SET_BEAM SET_SHELL SET_TSHELL LS DYNA Version 960 29 25 RESTART RESTART INTERFACE SPRINGBACK Purpose Define a material subset for an implicit springback calculation in LS NIKE3D and any nodal constraints to eliminate rigid body degrees of freedom Generally only the materials that make up the original blank are included in the springback calculation After termination of the LS DYNA3D computation an input deck for LS NIKE3D and a stress initialization file for LS NIKE3D are written Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PSID Part set ID for springback see SET PART Define a list of nodal points that are constrained for the spr
234. N 5 5 CONSTRAINED GLOBAL Ss seta ea Boe dte 5 18 CONSTRAINED INTERPOLATION eeeeeereeeeeereeeeneen eene entente 5 20 CONSTRAINED JOINT OPTION OPTION 5 24 CONSTRAINED JOINT STIFENESS OPTION eene 5 34 11 LS DYNA Version 960 TABLE OF CONTENTS CONSTRAINED LAGRANGE 5 5 44 e WO i len 5 47 CONSTRAINED_NODAL_RIGID_BODY_ 5 50 CONSTRAINED NODE SET oeir sb peor toot Tete e boe 5 55 CONSTRAINED POINTS ze Sag sees bt ong 2 8 Ba EE ae ea Dig 5 57 CONSTRAINED RIGID BODIES ser eere tices 2er ee desta een al 5 59 CONSTRAINED RIGID BODY STOPPERS eene 5 61 CONSTRAINED zRIVET ernst esed deese kr te Paseo ee erbe Eoo EP vase 5 64 CONSTRAINED SHELL SOLID tiit ir P 220802200 5 66 CONSTRAINED SPOTWELD OPTION eeeee mme 5 68 CONSTRAINED 5 72 CONSTRAINED TIED NODES 5 73 SCONTACT ee te HD ine VEN Fee o oU T oA CURE 6 1 CONTACT OPTION2 OPTIONS 6 2 CONTAGTI ENTIDY asia res 6 38 CONTACT GEBOD_OPTION neu mn 6 47 SCONTACT INTERIOR sn a ve e ien ue sot de bog Peur 6 50 CONTACT RIGID SURFACE
235. NA Version 960 COMPONENT Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 me fet et et et ete VARIABLE DESCRIPTION VX VY VZ Initial velocity of the dummy in the global x y and z directions GX GY GZ Global x y and z components of gravitational acceleration applied to the dummy 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 COMPONENT GEBOD MALE 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 6 A 50th percentile male dummy with the ID number of 7 is generated in the 8 lbf sec 2 inch sec system of units The dummy is given an initial velocity of 8 616 in sec in the negative x direction and gravity acts in the negative 2 direction with a value 386 in sec 2 COMPONENT GEBOD MALE did units size 7 10 50 vz gx gY gz 616 0 0 0 0 386 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 4 3 COMPONENT COMPONENT COMPONENT_GEBOD_JOINT_OPTION Purpose Alter the joint characteristics of a GEBOD rigid body dummy Setting a joint parameter value to zero retains the default value set internally See Appendix K for further details The following options are available PELVIS WAIST LOWER_NECK UPPER_NECK LEFT_SHOULDER RIGHT_SHOULDER LEFT_ELBOW RIGHT_ELBOW LEFT_HIP RIGHT_HIP LEFT_KNEE RIGHT_KNEE LEFT_ANKLE RIGHT_ANKLE Card 1 Required 1
236. NA Version 960 VARIABLE TSUBC PRTMCOL RBMCOL MCOLFILE Remarks BOUNDARY DESCRIPTION Time interval for MCOL subcycling EQ 0 0 no subcycling Time interval for output of MCOL rigid body data LS DYNA rigid body material assignment for the ship Filename containing MCOL input parameters for the ship basis for MCOL is a convolution integral approach for simulating the equations of motion A mass and inertia tensor are required as input for each ship The masses are then augmented to include the effects of the mass of the surrounding water A separate program determines the various terms of the damping buoyancy force formulas which are also input to MCOL The coupling is accomplished in a simple manner at each time step LS DYNA computes the resultant forces and moments on the MCOL rigid bodies and passes them to MCOL MCOL then updates the positions of the ships and returns the new rigid body locations to LS DYNA A more detailed theoretical and practical description of MCOL can be found in a separate report to appear 2 After the end of the LS DYNA MCOL calculation the analysis can be pursued using MCOL alone ENDTMCOL is the termination time for this analysis If ENDTMCOL is lower than the LS DYNA termination time the uncoupled analysis will not be activated 3 MCOL output is set to the files MCOLOUT ship position and MCOLENERGY energy breakdown In LS POST MCOLOUT can be plotted thro
237. NSTRAINED SHELL TO SOLID CONSTRAINED SPOTWELD OPTION CONSTRAINED TIE BREAK CONSTRAINED TIED NODES FAILURE LS DYNA Version 960 5 1 CONSTRAINED CONSTRAINED CONSTRAINED ADAPTIVITY Purpose Define an adaptive constraint which constrains a node to the midpoint along an edge of a shell element This keyword is also created by LS DYNA during an adaptive calculation This option applies to shell elements Card Format 1 2 3 4 5 6 7 8 u z VARIABLE DESCRIPTION SN Slave node This is the node constrained at the midpoint of an edge of a shell element MNI One node along the edge of the shell element MN2 The second node along the edge 5 2 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED EXTRA NODES OPTION Available options include NODE SET Purpose Define extra nodes for rigid body Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of rigid body to which the nodes will be added see PART NID NSID Node option NODE or node set ID option SET see SET NODE of added nodes Remarks Extra nodes for rigid bodies may be placed anywhere even outside the body and they are assumed to be part of the rigid body They have many uses including 1 definition of draw beads in metal forming applications by listing nodes along the draw bead 2 Placing nodes where joints will be attached between rigid bodies 3 Defining a nod
238. NT TRANSLATIONAL MOTOR CONSTRAINED JOINT ROTATIONAL MOTOR CONSTRAINED JOINT GEARS CONSTRAINED JOINT RACK AND PINION CONSTRAINED JOINT CONSTANT VELOCITY CONSTRAINED JOINT PULLEY CONSTRAINED JOINT SCREW If the force output data is to be transformed into a local coordinate then an additional option is available LOCAL Purpose Define a joint between two rigid bodies see Figure 5 6 Card Format Card 1 is required for all joint types Card 2 is required for joint types MOTOR GEARS RACK AND PINION PULLEY and SCREW Optional Card is required only if LOCAL is specified in the keyword In the first seven joint types above excepting the Universal joint the nodal points within the nodal pairs 1 2 3 4 and 5 6 see Figure 4 4 should coincide in the initial configuration and the nodal pairs should be as far apart as possible to obtain the best behavior For the Universal Joint the nodes within the nodal pair 3 4 do not coincide but the lines drawn between nodes 1 3 and 2 4 must be perpendicular 5 24 CONSTRAINED LS DYNA Version 960 CONSTRAINED The geometry of joints is defined in Figure 5 4 When the penalty method is used see CONTROL at each time step the relative penalty stiffness is multiplied by a function dependent on the step size to give the maximum stiffness that will not destroy the stability of the solution Instabilities can result in the explicit time integration scheme if the pe
239. OFT 1 or 2 on optional contact card A will cause the contact stiffness to be determined based on stability considerations taking into account the timestep and nodal masses This approach is generally more effective for contact between materials of dissimilar stiffness or dissimilar mesh densities SOFT 2 is for general shell and solid element contact This option is available for all SURFACE TO SURFACE ONE WAY SURFACE TO SURFACE and SINGLE SURFACE options When the AUTOMATIC option is used orientation of shell segment normals is automatic When the AUTOMATIC option is not used the segment or element orientations are used as input The alternate penalty formulation contact algorithm checks for segments vs segment penetration rather than node vs segment After penetrating segments are found an automatic judgment is made as to which is the master segment and penalty forces are applied normal to that segment The user may override this automatic judgment by using the ONE WAY options in which case the master segment normals are used as input by the user The EDGE parameter on optional card A is used to enable a segment edge to segment edge penetration check Setting EDGE 0 disables this check and is recommended when edge penetrations are not likely to occur Setting EDGE gt 0 enables the edge edge penetration judgment and EDGE 1 is recommended Smaller values may be tried if problems occur when the EDGE option is active In this version all parameter
240. ONTACT 2DAUTO allows the deletion of 2D automatic contact definitions The keyword LOAD BEAM is added for pressure boundary conditions on 2D elements A viscoplastic strain rate option is available for materials MAT PLASTIC KINEMATIC MAT JOHNSON COOK MAT POWER LAW PLASTICITY 1 6 INTRODUCTION LS DYNA Version 960 LS DYNA INTRODUCTION MAT_STRAIN_RATE_DEPENDENT_PLASTICITY MAT_PIECEWISE_LINEAR_PLASTICITY MAT_RATE_SENSITIVE_POWERLAW_PLASTICITY MAT_ZERILLI ARMSTRONG MAT_PLASTICITY_WITH_DAMAGE MAT_PLASTICITY_COMPRESSION_TENSION Material model MAT_PLASTICITY_WITH_DAMAGE has a piecewise linear damage curve given by a load curve ID The Arruda Boyce hyper viscoelastic rubber model is available see MAT_ ARRUDA_BOYCE Transverse anisotropic viscoelastic material for heart tissue see MAT_HEART_ TISSUE Lung hyper viscoelastic material see MAT_LUNG_TISSUE Compression tension plasticity model see MAT_PLASTICITY_COMPRESSION_ TENSION The Lund strain rate model MAT_STEINBERG_LUND is added to Steinberg Guinan plasticity model Rate sensitive foam model FU CHANG has been extended to include engineering strain rates etc Model MAT_MODIFIED_PIECEWISE_LINEAR_PLASTICITY is added for modeling the failure of aluminum Material model MAT_SPECIAL_ ORTHOTROPIC added for television shadow mask problems Erosion strain is implemented for material type MAT_BAMMAN_DAMAGE The equation of state EOS JWLB
241. ONTACT_ is the general 3D contact algorithms The second CONTACT ENTITY treats contact using mathematical functions to describe the surface geometry for the master surface The third CONTACT GEBOD is a specialized form of the contact entity for use with the rigid body dummies see COMPONENT GEBOD The fourth CONTACT INTERIOR is under development and is used with soft foams where element inversion is sometimes a problem Contact between layers of brick elements is treated to eliminate negative volumes The fifth CONTACT RIGID SURFACE is for modeling road surfaces for durability and NVH calculations The sixth CONTACT 1D remains in LS DYNA for historical reasons and is sometimes still used to model rebars which run along edges of brick elements The last CONTACT 2D is the general 2D contact algorithm based on those used previously in LS DYNA2D LS DYNA Version 960 6 1 CONTACT CONTACT CONTACT_ OPTION _ OPTION2 _ OPTION3 _ OPTION4 Purpose Define a contact interface OPTION specifies the contact type Not all options are implemented for implicit solutions A list of avaiable contact options is given in remark 4 AIRBAG_SINGLE_SURFACE AUTOMATIC_GENERAL AUTOMATIC_GENERAL_INTERIOR AUTOMATIC_NODES_TO_SURFACE AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_TIEBREAK AUTOMATIC_SINGLE_SURFACE AUTOMATIC_SURFACE_TO_SURFACE AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK CONSTRAINT_NODES_TO_SURFACE CONSTRAINT_S
242. ONTROL_NONLOCAL Purpose Allocate additional memory for MAT NONLOCAL option Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MEM Percentage increase of memory allocated for MAT_NONLOCAL option over that required initially This is for additional storage that may be required due to geometry changes as the calculation proceeds Generally a vaiue of 10 should be sufficient LS DYNA Version 960 7 59 CONTROL CONTROL CONTROL_OUTPUT Purpose Set miscellaneous output parameters This keyword does not control the information such as the stress and strain tensors which is written into the binary databases For the latter see the keyword DATABASE_EXTENT_BINARY Card Format 1 2 3 4 5 6 7 8 Optional Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NPOPT Print suppression during input phase flag for the printed output file 0 no suppression EQ 1 nodal coordinates element connectivities rigid wall definitions and initial velocities are not printed NEECHO Print suppression during input phase flag for echo file 0 all data printed EQ 1 nodal printing is suppressed EQ 2 element printing is suppressed EQ 3 both node and element printing is suppressed 7 60 CONTROL LS DYNA Version 960 VARIABLE NREFUP IACCOP OPIFS IPNINT IKEDIT IFLUSH IPRTF LS DYNA Version 960 CONTROL DESCRIPTION Flag to update reference node coordinates for beam elem
243. ORS Gears define R R Rack and Pinion define h Pulley define R Screw define x LCID Define load curve ID for MOTOR joints TYPE Define integer flag for MOTOR joints as follows 0 translational rotational velocity EQ 1 translational rotational acceleration EQ 2 translational rotational displacement RI Radius R for the gear and pulley joint type If left undefined nodal points 5 and 6 are assumed to be on the outer radius Optional Card Format Required only if LOCAL is specified after the keyword Card 1 1 2 3 4 5 6 7 8 5 26 CONSTRAINED LS DYNA Version 960 VARIABLE RAID LST LS DYNA Version 960 CONSTRAINED DESCRIPTION Rigid body or accelerometer ID The force resultants are output in the local system of the rigid body or accelerometer Flag for local system type EQ 0 rigid body EQ 1 accelerometer 5 27 CONSTRAINED CONSTRAINED Cylindrical joint Planar joint Universal joint Translational joint Figure 5 6 Joint definitions 1 6 Locking joint Figure 5 7 Locking joint 5 28 CONSTRAINED LS DYNA Version 960 CONSTRAINED A Load curve defines relative motion Figure 5 8 Translational motor joint This joint can be used in combination with the translational or the cylindrical joint Load curve defines relative rotational motion in radians per unit time Figure 5 9 Rotational motor joint This joint can be used in combination wit
244. PTION MASS Total mass of stonewall vo Initial velocity of stonewall in direction of defining vector n 22 18 RIGIDWALL LS DYNA Version 960 RIGIDWALL Optional Card E Required if FORCES is specified after the keyword This option allows the force distribution to be monitored on the plane Also four points can be defined for visualization of the rigid wall A shell or membrane element must be defined with these four points as the connectivity for viewing in LS POST Optional 1 Card E 2 3 4 5 6 7 8 ISIDBISLELI 1 VARIABLE DESCRIPTION SOFT Number of cycles to zero relative velocity to reduce force spike SSID Segment set identification number for defining areas for force output see SET SEGMENT and remark 1 below NI Optional nodal point for visualization in LS DYNA database see remark 2 below N2 N4 Optional nodal points for visualization Remarks 1 The segment set defines areas for computing resultant forces These segments translate with the moving stonewall and allow the forced distribution to be determined The resultant forces are written in file RWFORC 2 four nodes are for visualizing the movement of the wall i e they move with the wall To view the wall in LS POST it is necessary to define a single shell element with these four nodes as its connectivity The single element must be deformable non rigid or else the segment will be treated as a rigid body and the nodes will have
245. QM is taken as the membrane hourglass coefficient the bending as QB and warping as QW These coefficients can be specified independently but generally is adequate For type 6 solid element hourglass control QM 1 0 gives an accurate coarse mesh bending stiffness that does not lock in the incompressible limit For type 6 values such as 0 001 0 01 will avoid an overly stiff response IBQ Bulk viscosity type See remark 3 below EQ 1 standard LS DYNA Q2 Quadratic bulk viscosity coefficient Ql Linear bulk viscosity coefficient QB Hourglass coefficient for shell bending The default QB QM See remark 4 below QW Hourglass coefficient for shell warping The default QB QW Remarks l Viscous hourglass control is recommended for problems deforming with high velocities Stiffness control is often preferable for lower velocities especially if the number of time steps are large For solid elements the exact volume integration provides some advantage for highly distorted elements For automotive crash the stiffness form of the hourglass control with a coefficient of 0 05 is preferred by many users Bulk viscosity is necessary to propagate shock waves in solid materials and therefore applies only to solid elements Generally the default values are okay except in problems where pressures are very high larger values may be desirable In low density foams it may be necessary to reduce the viscosity values since th
246. RETENSIONER Purpose Define seat belt pretensioner A combination with sensors and retractors is also possible Card Format 1 2 3 4 5 6 7 8 I 1 2 VARIABLE DESCRIPTION SBPRID Pretensioner ID A unique number has to be used SBPRTY Pretensioner type EQ 1 pyrotechnic retractor EQ 2 pre loaded spring becomes active EQ 3 lock spring removed 12 16 ELEMENT LS DYNA Version 960 ELEMENT VARIABLE DESCRIPTION SBSID1 Sensor 1 see ELEMENT_SEATBELT_SENSOR SBSID2 Sensor 2 see ELEMENT_SEATBELT_SENSOR SBSID3 Sensor 3 see ELEMENT_SEATBELT_SENSOR SBSID4 Sensor 4 see ELEMENT_SEATBELT_SENSOR SBRID Retractor number SBPRTY 1 or spring element number SBPRTY 2 or 3 TIME Time between sensor triggering and pretensioner acting PTLCID Load curve for pretensioner Time after activation Pull in SBPRTY 1 Remarks 1 Atleast one sensor should be defined Pretensioners allow modeling of three types of active devices which tighten the belt during the initial stages of a crash The first type represents a pyrotechnic device which spins the spool of a retractor causing the belt to be reeled in The user defines a pull in versus time curve which applies once the pretensioner activates The remaining types represent preloaded springs or torsion bars which move the buckle when released The pretensioner is associated with any type of spring element
247. RTE MIO VE re nee Ra 21 13 RIGID W AD iur Id RE M D M EA aM EH E E s 22 1 RIGIDWALL GEOMETRIC OPTION OPTION 22 2 RIGIDWALL PLANAR OPTION OPTION OPTION 22 12 NSEGTION ade tite eee AeA etek 23 1 SECTION BEAM ostio tette te 23 2 5 _ 1 2 2 ME eio 23 8 SSECTIONGSEATBEBDE he ne 23 11 SECTION SHELL OPTION u ana eignen 23 12 SECTION SOLID OPHON MR VD URS 23 20 BBS EMI ONS PEL Se een 23 24 SSECTIONGDSHEDD 2 ee Sak roe tas MD 23 25 SET uec MM 24 1 BEAM OPTION ta T 242 he ame 24 5 SET NODE SOP TION 24 8 SET PART OPINOR esse en a le 24 12 SET SEGMENT TOFHON vised Ot as 2415 SET we 24 19 esse 24 23 POET TSE CORTON ee ee 24 26 FTERMINATION See este 25 1 KTERMINATIONZNODE nein 25 2 PER MINA TION BODY enteo chin 25 3 H TERMINATION CONTACT 25 te tele E eo tU cti 25 4 LS DYNA Version 960 TABLE OF CONTENTS EDT 26 1 xu B EU EI oH 26 1 TRANSLATE vei P ores dora odis aisles 27
248. S DYNA Version 960 CONTACT This Card 4 is mandatory for CONTACT_ DRAWBEAD Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCIDRF If LCIDRF is positive then it defibes the load curve ID giving the bending component of the restraining force F pending per unit draw bead length as function of displacement 8 see Figure 6 2 This force is due to the bending and unbending of the blank as it moves through the drawbead The total restraining force is the sum of the bending and friction components If LCIDRF is negative then the absolute value gives the load curve ID defining max bead force versus normalized drawbead length The abscissa values is between zero and 1 and is the normalized drawbead length The ordinate gives the maximum allowed drawbead retaining force when the bead is in the fully closed position If the drawbead is not fully closed linear interpolation is used to compute the drawbead force LCIDNF Load curve ID giving the normal force per unit draw bead length as a function of displacement 6 see Figure 6 2 This force is due to the bending of the blank into the draw bead as the binder closes on the die and represents a limiting value The normal force begins to develop when the distance between the die and binder is less than the draw bead depth As the binder and die close on the blank this force should diminish or reach a plateau see the explanation below DBDTH Draw bead depth see Figure 6 2 Necessary to det
249. SCRIPTION Thermal material property identification defined in the MAT THERMAL Section Thermal properties must be specified for all solid shell and thick shell parts if a thermal or coupled thermal structural analysis is being performed Beams and discrete elements are not considered in thermal analyses EQ 0 defaults to MID x coordinate of center of mass If nodal point NODEID is defined XC YC and ZC are ignored and the coordinates of the nodal point NODEID are taken as the center of mass y coordinate of center of mass Z coordinate of center of mass Translational mass Flag for inertia tensor reference coordinate system EQ 0 global inertia tensor EQ 1 local inertia tensor is given in a system defined by the orientation vectors Nodal point defining the CG of the rigid body This node should be included as an extra node for the rigid body however this is not a requirement If this node is free its motion will not be updated to correspond with the rigid body after the calculation begins Ix xx component of inertia tensor Ixy xy component of inertia tensor see Remark 4 Ixz xz component of inertia tensor see Remark 4 yy component of inertia tensor Iyz yz component of inertia tensor see Remark 4 Izz ZZ component of inertia tensor initial translational velocity of rigid body in x direction initial translational velocity of rigid body in y direction initial translational velocity of rigid body in z direction ini
250. STRAN Name of damping matrix in the file defined by FILENAME This filename should be no more than eight characters to be compatible with NASTRAN Name of stiffness matrix in the file defined by FILENAME This filename should be no more than eight characters to be compatible with NASTRAN 12 9 ELEMENT ELEMENT ELEMENT DISCRETE Purpose Define a discrete spring or damper element between two nodes or a node and ground It is recommended that beam type 6 see ELEMENT BEAM and SECTION BEAM be used whenever possible especially if orientation is specified The latter option tends to be more accurate and cost effective The ELEMENT DISCRETE option is no longer be developed and extended Note These elements enter into the time step calculations Care must be taken to ensure that the nodal masses connected by the springs and dampers are defined and unrealistically high stiffness and damping values must be avoided All rotations are in radians Card Format 518 16 0 18 16 0 _VARIABLE DESCRIPTION EID Element ID A unique number has to be used PID Part ID see PART NI Nodal point 1 N2 Nodal point 2 If zero the spring damper connects node NI to ground VID Orientation option The orientation option should be used cautiously since forces which are generated as the nodal points displace are not orthogonal to rigid body rotation unless the nodes are coincident The type 6 3D beam element is recommended when orientati
251. SURFACE TIED_SHELL_EDGE_TO_SURFACE SPOTWELD SPOTWELD_WITH_TORSION TIED_SURFACE_TO_SURFACE These contact definitions are based on constraint equations and will not work with rigid bodies However tied interfaces with the offset option can be used with rigid bodies i e TIED_NODES_TO_SURFACE_OFFSET TIED_SHELL_EDGE_TO_SURFACE_OFFSET TIED_SURFACE_TO_SURFACE_OFFSET Also it may sometimes be advantageous to use the CONSTRAINED_EXTRA_NODE_ OPTION instead for tying deformable nodes to rigid bodies since in this latter case the tied nodes may be an arbitrary distance away from the rigid body Tying will only work if the sufaces are near each other The criteria used to determine whether a slave node is tied down is that it must be close For shell elements close is defined as as distance less than 0 60 thickness_ slave_node thickness master segment 0 05 min master segment _diagonals max 6 6 If a node is further away it will not be tied and a warning message will be printed For solid elements the slave node thickness is zero otherwise the same procedure is used If there is a large difference in element areas between the master and slave side the distance may be too large and may cause the unexpected projection of nodes that should not be tied This can occur during calculation when adaptive remeshing is used To avoid this difficulty the slave and master thickness can be specified as negative v
252. T 5 306 MAT JOHNSON HOLMQUIST 309 MAT FINITE ELASTIC STRAIN 2 312 MAT LAYERED LINEAR PLASTICITY 315 MAT UNIFIED CREEP 2 REIR ete en Piatti Rt 318 MAT COMPOSITE E AYUP icto erect eae Harman es E EA 319 MAT COMPOSITE MATRIX erige t pete ER ses erkenne 322 MAT GOMPOSITE DIRECGT ect o EROR A 325 MAT_GURSON Mm 327 MAT MODIFIED PIECEWISE LINEAR PLASTICITY eee 331 MAT PLASTICITY COMPRESSION 334 MAT MODIFIED HONEYCOMB tete ae ni ern un 336 MAT ARRUDA BOYCE RUBBER 1 2 er hh hh Hee eh Henne nnne 343 MAT HEARTSTISSUE aneinander Eo ees a eden 346 MAT LUNG TISSUE oss ete 2 2 obec sey espe ges eret ire TAPA hae eas Diebe rede 349 MAT SPECIAL ORTHOTROBIC o erre E ER EE E Bee ese 352 MAT MODIFIED FORCE LIMITED 356 MAT COMPOSTITE MSG nun eines ded pret Agee ERR 367 MAT SEISMIC BEAM tie Hebr el etr ee sided e O t RD 376 MAT SOIL BRICK cies ouiro Rote oie ORE iie nates 379 MAT DRUCKER PR GER 2 u 381 MATIRCESHEAR WALL u aa en este HE 384 MAT CONERETE BEAM 2 entier e eio in RS 390 MAT LINEAR ELASTIC DISCRETE 393 MAT NON
253. TION SECTION VARIABLE QR ICOMP Bl B2 B3 B8 Bnip DESCRIPTION Quadrature rule LT 0 0 absolute value is specified rule number EQ 0 0 Gauss up to five points are permitted EQ 1 0 trapezoidal not recommended for accuracy reasons Flag for layered composite material mode EQ 1 a material angle is defined for each through thickness integration point For each layer one integration point is used 1 material angle at first integration point The same procedure for determining material directions is use for thick shells that is used for the 4 node quadrilateral shell B material angle at second integration point material angle at third integration point Bg material angle at eigth integration point material angle at nipth integration point Define as many cards as necessary until NIP points are defined Remarks 1 Thick shell formulation type 3 uses a full three dimensional stress update rather than the two dimensional plane stress update of types 1 and 2 The type 3 element is distortion sensitive and should not be used in situations where the elements are badly shaped With element types 1 and 2 a single element through the thickness will capture bending response but with element type 3 two are recommended to avoid excessive softness 2 These elements are available for implicit applications 23 26 SECTION LS DYNA Version 960 SET SET The keyword SET provide
254. TION SECTION_SEATBELT Purpose Define section properties for the seat belt elements This card is required for the PART Section Currently only the ID is required Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SECID Section ID Remarks 1 Seatbelt elements are not implicit for implicit calculations 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 SECTION SEATBELT 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Define seat belt section that is referenced by part 10 Nothing more than the sid is required SECTION SEATBELT 5 Sip ee Dea e dunes ap evel 5 sid 111 PART 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 23 11 SECTION SECTION SECTION_SHELL_ OPTION Options include lt BLANK gt ALE such that the keyword cards appear SECTION_SHELL SECTION_SHELL_ALE Purpose Define section properties for shell elements Card Format Card 1 1 2 3 4 5 6 7 8 ENEIENEZENEIEIENEN mL Id Card 2 1 2 3 4 5 6 7 8 EIER EN Ca 23 12 SECTION LS DYNA Version 960 SECTION Optional Section Cards if ICOMP 1 Define NIP angles putting 8 on each card Cards 3 4 Optional Section Card for ALE option Also see CONTROL_ALE and ALE_SMOOTHING Card
255. TION is specified without further input STRESS INITIALIZATION SEATBELT Initialize all seatbelt parts from the old parts No further input is required with this card This card is not required if STRESS INITIALIZATION is specified without further input LS DYNA Version 960 29 33 RESTART RESTART TERMINATION OPTION Purpose Stop the job depending on some displacement conditions Available options include NODE BODY Caution The inputs are different for the nodal and rigid body stop conditions The nodal stop condition works on the global coordinate position while the body stop condition works on the relative global translation The number of termination conditions cannot exceed the maximum of 10 or the number specified in the original analysis The analysis terminates for TERMINATION NODE when the current position of the node specified reaches either the maximum or minimum value stops 1 2 or 3 or picks up force from any contact surface stop 4 For TERMINATION BODY the analysis terminates when the center of mass displacement of the rigid body specified reaches either the maximum or minimum value stops 1 2 or 3 or the displacement magnitude of the center of mass is exceeded stop 4 If more than one condition is input the analysis stops when any of the conditions is satisfied This input completely overides the existing termination conditions defined in the time zero run Termination by other means is controlled by the
256. TOMATIC_SURFACE_TO_SURFACE SINGLE_SURFACE NODES_TO_SURFACE AUTOMATIC_NODES_TO_SURFACE TIED_NODES_TO_SURFACE TIED_SHELL_EDGE_TO_SURFACE TIEBREAK_NODES_TO_SURFACE TIEBREAK_SURFACE_TO_SURFACE ONE_WAY_SURFACE_TO_SURFACE AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE AUTOMATIC_SINGLE_SURFACE 13 AIRBAG_SINGLE_SURFACE gt e 14 ERODING_SURFACE_TO_SURFACE 15 ERODING_SINGLE_SURFACE 16 ERODING_NODES_TO_SURFACE 17 CONSTRAINT_SURFACE_TO_SURFACE 18 CONSTRAINT_NODES_TO_SURFACE 19 RIGID_BODY_TWO_WAY_TO_RIGID_BODY 20 RIGID_NODES_TO_RIGID_BODY 21 RIGID_BODY_ONE_WAY_TO_RIGID_BODY 22 SINGLE_EDGE 23 DRAWBEAD The CONTACT_ENTITY section treats contact between a rigid surface usually defined as an analytical surface and a deformable structure Applications of this type of contact exist in the metal forming area where the punch and die surface geometries can be input as VDA surfaces which are treated as rigid Another application is treating contact between rigid body occupant dummy hyper ellipsoids and deformable structures such as airbags and instrument panels This option is particularly valuable in coupling with the rigid body occupant modeling codes MADYMO and CAL3D The CONTACT_ID is for modeling rebars in concrete structure CONTROL Options available in the CONTROL section allow the resetting of default global parameters such as the hourglass type the contact penalty scale
257. T_IO pl p2 p3 al a2 a3 a4 Generate segments of parts pl p2 p3 with attributes al a4 Same as the PART option above except that inter element segments inside parts will be generated as well This option is sometimes useful for single surface contact of solid elements to prevent negative volumes caused be inversion LS DYNA Version 960 24 17 SET SET FORMAT A10 7110 DBOX bl b2 b3 b4 b5 b6 b7 Segments inside boxes 1 b2 previously added will be excluded DBOX SHELL bl b2 b3 b4 b5 b6 b7 Shell related segments inside boxes bl b2 previously added will be excluded DBOX SOLID bl b2 b3 b4 b5 b6 b7 Solid related segments inside boxes bl b2 previously added will be excluded DPART pl p2 p3 p4 p5 p6 p7 Segments of parts pl p2 p3 previously added will be excluded DSEG nl n2 n3 n4 Segments with node ID s n1 n2 n3 and n4 previously added will be deleted The numbering sequence is irrelevant nl n2 n3 n4 Create segment with node ID s n1 n2 n3 and n4 t Remarks 1 Segment attributes be assigned for some input types For example for the contact options the attributes for the SLAVE surface are DA1 NFLS Normal failure stress SURFACE contact only DA2 SFLS Shear failure stress CONTACT_TIEBREAK_ SURFACE contact only DA3 FSF Coulomb friction scale factor DA4 VSF Viscous friction scale factor and the attributes for t
258. This option applies only to contact with shell elements True thickness is the element thickness of the shell elements For the TIED options see SST above SFST Scale factor for slave surface thickness scales true thickness This option applies only to contact with shell elements True thickness is the element thickness of the shell elements SFMT Scale factor for master surface thickness scales true thickness This option applies only to contact with shell elements True thickness is the element thickness of the shell elements FSF Coulomb friction scale factor The Coulomb friction value is scaled as HU FSF u see above VSF Viscous friction scale factor If this factor is defined then the limiting force becomes VSF VC A see above lim cont LS DYNA Version 960 6 11 CONTACT CONTACT Remarks The variables FSF and VSF above can be overridden segment by segment on the SET_SEGMENT or SET_SHELL_ OPTION cards for the slave surface only as A3 and A4 and for the master surface only as Al and A2 See SET_SEGMENT and SET_SHELL_OPTION This Card 4 is mandatory for CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE_TIEBREAK Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION OPTION Response EQ 1 slave nodes in contact and which come into contact will permanently stick Tangential motion is inhibited EQ 2 tiebreak is active for nodes which are in
259. This input terminates when the next card is encountered See the PENCHK variable on the CONTACT definition Card Format 1 2 3 4 5 6 7 8 veme I fm os oe om me VARIABLE DESCRIPTION IDn Contact ID for surface number n The CURVE_DEFINITION option allows a load curve to be redefined The new load curve must contain the same number of points as the curve it replaces The curve should be defined in the DEFINE_CURVE section of this manual This input terminates when the next card is encountered Any offsets and scale factors are ignored Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID LS DYNA Version 960 29 5 RESTART RESTART The RIGID BODY CONSTRAINT option allows translational and rotational boundary conditions on a rigid body to be changed This input terminates when the next card is encountered Also see CONSTRAINED RIGID BODIES Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID see PART TC Translational constraint EQ 0 EQ 1 2 3 4 5 6 EQ 7 no constraints constrained x displacement constrained y displacement constrained z displacement constrained x and y displacements constrained y and z displacements constrained z and x displacements constrained x y and z displacements RC Rotational constraint EQ 0 EQ 1 2 EQ 3 EQ 4 EQ 5 EQ 6
260. This is the nth user input parmeter LS DYNA Version 960 28 3 USER USER 28 4 USER LS DYNA Version 960 RESTART RESTART INPUT DATA In general three categories of restart actions are possible with LS DYNA and are outlined in the following discussion a b A simple restart occurs when LS DYNA was interactively stopped before reaching the termination time Then simply defining the R rtf file on the execution line for LS DYNA restarts the calculation from the termnination point and the calculation will continue to the specified termination time see INTRODUCTION Execution Syntax No additional input deck is required If minor modifications are desired as e g e reset termination time reset output printing interval reset output plotting interval e delete contact surfaces delete elements and parts e switch deformable bodies to rigid e switch rigid bodies to deformable change damping options This type of restart is called a small restart and the corresponding input deck a small restart input deck All modifications to the problem made with the restart input deck will be reflected in subsequent restart dumps All the members of the file families are consecutively numbered beginning from the last member The small input deck replaces the standard input deck on the execution line which has at least the following contents LS DYNA Isrestartinput R D3DUMPnn where D3DUMPnn or whatever name is ch
261. This line of nodes will be constrained to remain linear throughout the simulation The direction of this line will be kept the same as the fiber of the of the shell containing node 329 4 4 4 4 4 4 4 4 4 4 4 4 CONSTRAINED SHELL SOLID 5 nid nsid 329 4 SET NODE LIST sid 4 5 nidi nid2 nid3 nid4 nid5 nid6 nid7 nid8 119 161 203 245 287 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 LS DYNA Version 960 5 67 CONSTRAINED CONSTRAINED CONSTRAINED SPOTWELD OPTION If it is desired to use a time filtered force calculation for the forced basae failure criterion then the following option is available FILTERED FORCE and one additional card must be defined below Purpose Define massless spot welds between non contiguous nodal pairs The spot weld is a rigid beam that connects the nodal points of the nodal pairs thus nodal rotations and displacements are coupled The spot welds must be connected to nodes having rotary inertias i e beams or shells If this is not the case for example if the nodes belong to solid elements use the option CONSTRAINED RIVET Note that shell elements do not have rotary stiffness in the normal direction and therefore this component cannot be transmitted Spot welded nodes must not have the same coordinates Coincident nodes in spot weld can be handeled by the CONSTRAINED NODAL RIGID BODY option Brittle and ductile failures can b
262. URFACE_TO_SURFACE DRAWBEAD ERODING_NODES_TO_SURFACE ERODING_SINGLE_SURFACE ERODING_SURFACE_TO_SURFACE FORCE_TRANSDUCER_CONSTRAINT FORCE_TRANSDUCER_PENALTY FORMING NODES TO SURFACE FORMING ONE WAY SURFACE TO SURFACE FORMING SURFACE TO SURFACE NODES TO SURFACE NODES TO SURFACE INTERFERENCE ONE WAY SURFACE TO SURFACE ONE WAY SURFACE TO SURFACE INTERFERENCE RIGID NODES TO RIGID BODY RIGID BODY ONE WAY TO RIGID BODY RIGID BODY TWO WAY TO RIGID BODY SINGLE EDGE SINGLE SURFACE SLIDING ONLY SLIDING ONLY PENALTY 6 2 CONTACT LS DYNA Version 960 CONTACT SPOTWELD SPOTWELD_WITH_TORSION SURFACE_TO_SURFACE SURFACE_TO_SURFACE_INTERFERENCE TIEBREAK_NODES_TO_SURFACE TIEBREAK_NODES_ONLY TIEBREAK_SURFACE_TO_SURFACE TIED_NODES_TO_SURFACE TIED_SHELL_EDGE_TO_SURFACE TIED_SURFACE_TO_SURFACE TIED_SURFACE_TO_SURFACE_FAILURE OPTION2 specifies a thermal contact and takes the single option THERMAL Only the SURFACE TO SURFACE contact type may be used with this option OPTIONS specifies that the first card to read defines the title and ID number of contact interface and takes the single option TITLE OPTION4 specifies that offsets may be used with the tied contacts types and takes the single option OFFSET Only contact types TIED NODES TO SURFACE TIED SHELL EDGE TO SURFACE and TIED SURFACE TO SURFACE may be used with this option If this option is set then offsets are permitted for these contact types and if n
263. VARIABLE DESCRIPTION ENDTIM Termination time EQ 0 0 Termination time remains unchanged ENDCYC Termination cycle The termination cycle is optional and will be used if the specified cycle is reached before the termination time EQ 0 0 Termination cycle remains unchanged This is a reduced version of the CONTROL_TERMINATION card used in the initial input deck 29 18 RESTART LS DYNA Version 960 RESTART CONTROL TIMESTEP Purpose Set time step size control using different options Card Format 1 2 3 4 5 6 7 8 tet et et tet VARIABLE DESCRIPTION DUMMY Dummy field see remark 1 below TSSFAC Scale factor for computed time step EQ 0 0 TSSFAC remains unchanged ISDO Basis of time size calculation for 4 node shell elements ISDO 3 node shells use the shortest altitude for options 0 1 and the shortest side for option 2 This option has no relevance to solid elements which use a length based on the element volume divided by the largest surface area 0 characteristic length area longest side EQ 1 characteristic length area longest diagonal EQ 2 based on bar wave speed and MAX shortest side area longest side THIS LAST OPTION CAN GIVE A MUCH LARGER TIME STEP SIZE THAT CAN LEAD TO INSTABILITIES IN SOME APPLICATIONS ESPECIALLY WHEN TRIANGULAR ELEMENTS ARE USED DUMMY Dummy field see remark 1 below DT2MS New time step for mass scaled calculations Mass scaling must be active in the time z
264. Version 960 DATABASE VARIABLE DESCRIPTION SHGE Output shell hourglass energy EQ 1 off default no hourglass energy written EQ 2 on STSSZ Output shell element time step mass or added mass EQ 1 off default EQ 2 output time step size EQ 3 output mass added mass or time step size See remark 3 below N3THDT Material energy write option for D3THDT database EQ 1 off energy is NOT written to D3THDT database EQ 2 on default energy is written to D3THDT database Remarks l If MAXINT is set to 3 then mid surface inner surface and outer surface stresses are output at the center of the element to the LS DYNA database For an even number of integration points the points closest to the center are averaged to obtain the midsurface values If multiple integration points are used in the shell plane the stresses at the center of the element are found by computing the average of these points For MAXINT equal to 3 LS DYNA assumes that the data for the user defined integration rules are ordered from bottom to top even if this is not the case If MAXINT is not equal to 3 then the stresses at the center of the element are output in the order that they are stored for the selected integration rule If multiple points are used in plane the stresses are first averaged Beam stresses are output to the LS DYNA database if and only if BEAMIP is greater than zero In this latter case the data that is output is written in t
265. YNA Version 960 3 45 BOUNDARY BOUNDARY BOUNDARY SYMMETRY FAILURE Purpose Define a symmetry plane with a failure criterion This option applies to continuum domains modeled with solid elements Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT FS Tensile failure stress gt 0 0 The average stress in the elements surrounding the boundary nodes in a direction perpendicular to the boundary is used VTX x coordinate of tail of anormal vector originating on the wall tail and terminating in the body head 1 vector points from the symmetry plane into the body VTY y coordinate of tail VTZ z coordinate of tail VHX x coordinate of head VHY y coordinate of head VHZ z coordinate of head Remarks A plane of symmetry is assumed for the nodes on the boundary at the tail of the vector given above Only the motion perpendicular to the symmetry plane is constrained After failure the nodes are set free 3 46 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY TEMPERATURE OPTION Available options are NODE SET Purpose Define temperature boundary conditions for a thermal or coupled thermal structural analysis Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID SID Node ID Node Set ID see SET_NODE_OPTION LCID Load curve ID for temperature versus time EQ 0 use the constant multiplier value given below by CMULT CMULT Curve multiplier for temperatur
266. _DRAWBEAD CONTACT_ERODING_type CONTACT_ INTERFERENCE CONTACT_RIGID_type CONTACT_TIEBREAK_type Each of these types have different Card 4 formats These card formats are presented in this manual after the optional cards specified above but if used Card 4 needs to be specified in your dyna deck before the optional cards e Card for the THERMAL option is inserted here otherwise do not define this card Additional parameters are required for thermal contact and are defined on this card e Optional Card A Additional contact parameters that may be user specified Default values have evolved over time to become pretty good values for most circumstances e Optional Card B Additional contact parameters that may be user specified Default values have evolved over time to become pretty good values for most circumstances If Optional Card B is used then Optional Card A is mandatory use a blank line if no changes are desired for Card A parameters LS DYNA Version 960 6 5 CONTACT CONTACT The following card is read if and only if the TITLE option is specified Optional 1 2 The contact ID is needed during full deck restarts for contact initialization If the contact ID is undefined the default ID is determined by the sequence of the contact definitions i e the first contact definition has an ID of 1 the second 2 and so forth In a full deck restart without contact IDs for a successful run no contact interfaces c
267. a is created whenever the DEFGEO file is requested DEFORC Discrete elements ELOUT Element data See DATABASE HISTORY OPTION GCEOUT Geometric contact entities GLSTAT Global data Always obtained if SSSTAT file is activated JNTFORC Joint force file MATSUM Material energies See Remarks 1 and 2 below MOVIE MOVIE See DATABASE EXTENT OPTION MPGS MPGS See DATABASE EXTENT OPTION NCFORC Nodal interface forces See CONTACT Card 1 SPR and MPR NODFOR Nodal force groups See DATABASE NODAL FORCE GROUP NODOUT Nodal point data See DATABASE HISTORY OPTION RBDOUT Rigid body data See Remark 2 below RCFORC Resultant interface forces RWFORC Wall forces SBTOUT Seat belt output file SECFORC Cross section forces See DATABASE CROSS SECTION OPTION SLEOUT Sliding interface energy See CONTROL ENERGY SPCFORC SPC reaction forces SPHOUT SPH data See DATABASE HISTORY OPTION SSSTAT Subsystem data See DATABASE EXTENT SSSTAT SWFORC Nodal constraint reaction forces spotwelds and rivets TPRINT Thermal output from a coupled structural thermal or thermal only analysis TRHIST Tracer particle history information See DATABASE TRACER 9 2 DATABASE LS DYNA Version 960 Card Format 1 2 3 4 5 6 7 8 DATABASE DESCRIPTION VARIABLE DT Time interval between outputs If DT is zero no output is printed The file names and corresponding unit numbers are Airbag statistics ASCII database Boundary
268. a into RBDOUT and MATSUM 7 61 CONTROL CONTROL CONTROL_PARALLEL Purpose Control parallel processing usage for shared memory computers by defining the number of processors and invoking the optional consistency of the global vector assembly Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NCPU Number of cpus used NUMRHS Number of right hand sides allocated in memory EQ 0 same as NCPU always recommended EQ 1 allocate only one CONST Consistency flag for parallel solution NCPU gt 1 Option 2 is recommended for metal forming applications EQ 1 on EQ 2 off for a faster solution default PARA Flag for parallel force assembly if CONST 1 EQ 0 off EQ 1 on Remarks 1 Itis recommended to always set NUMRHS NCPU since great improvements in the parallel performance are obtained since the force assembly is then done in parallel Setting NUMRHS to one reduces storage by one right hand side vector for each additional processor after the first If the consistency flag is active 1 CONTST 1 NUMRHS defaults to unity 7 62 CONTROL LS DYNA Version 960 CONTROL 2 For any given problem with the consistency option off i e CONST 2 slight differences in results are seen when running the same job multiple times with the same number of processors and also when varying the number of processors Comparisons of nodal accelerations often show wide discrepancies however it is worth noting th
269. a is partitioned to the two nodes of the beam element The rotational time step size for the type 6 beam is dependent on the lumped inertia and the rotational stiffness values so it is important to define this parameter if the rotational springs are active Defining the rotational inertia is also essential for mass scaling if the type 6 beam rotational stiffness controls the time step size CID Coordinate system ID for orientation materials type ID 66 69 93 and 95 see DEFINE COORDINATE SYSTEM If CID 0 a default coordinate system is defined in the global system or on the third node of the beam which is used for orientation This option is not defined for material types than act between two nodal points such as cable elements The coordinate system rotates with the discrete beam see SCOOR above CA Cable area materials type ID 71 MAT_CABLE OFFSET Offset for cable For a definition see materials type ID 71 MAT_CABLE RRCON r rotational constraint for local coordinate system EQ 0 0 Coordinate ID rotates about r axis with nodes EQ 1 0 Rotation is constrained about the r axis SRCON s rotational constraint for local coordinate system EQ 0 0 Coordinate ID rotates about s axis with nodes EQ 1 0 Rotation is constrained about the s axis TRCON t rotational constraint for local coordinate system EQ 0 0 Coordinate ID rotates about t axis with nodes EQ 1 0 Rotation is constrained about the t axis Remarks 1 For implicit calc
270. a numerical problem and obtaining output at more frequent intervals it is often possible to identify where the first symptoms appear and what aspect of the model is causing them The format of the restart input file is described in this manual If for example the user wishes to restart the analysis from dump state nn contained in file D2DUMPnn then the following procedure is followed 1 Create the restart input deck if required as described in the Restart Section of this manual Call this file restartinput 2 By invoking the execution line LS DYNA I restartinput R D3DUMPnn execution begins If no alterations to the model are made then the execution line LS DYNA R D3DUMPnn will suffice Of course the other output files should be assigned names if the defaults have been changed in the original run The R D3DUMPnn on the status line informs the program that this is a restart analysis The full deck restart option allows the user to begin a new analysis with deformed shapes and stresses carried forward from a previous analysis for selected materials The new analysis can be different from the original e g more contact surfaces different geometry of parts which are not carried forward etc Examples of applications include e Crash analysis continued with extra contact surfaces Sheet metalforming continued with different tools for modeling a multi stage forming process Assume an analysis is run using the input file jobl i
271. a thickness exists between the slide surfaces then the conductance due to thermal conductivity between the slide surfaces is k cond E Lo Note that LS DYNA calculates based on deformation FRAD Radiation factor f between the slide surfaces A radient heat transfer coefficient is calculated see BOUNDARY RADIATION If a gap exists between the slide surfaces then the contact conductance is calculated by h h cond h rad HTC Heat transfer conductance h for closed gaps Use this heat transfer conductance for gaps in the range O lt S Lap S Lmin where ln is GCRIT defined below GCRIT Critical gap use the heat transfer conductance defined HTC for gap thicknesses less than this value 6 22 CONTACT LS DYNA Version 960 CONTACT VARIABLE DESCRIPTION GMAX No thermal contact if gap is greater than this value Lpa CD_FACT Is a multiplier used on the element characteristic distance for the search routine The characteristic length is the largest interface surface element diagonal EQ 0 Default set to 1 0 Remarks In summary h h if the gap thickness is OS Lap lt Lmin cont h Iona Nyaa 1f the gap thickness is Lyin SL S Lmax max h 0 if the gap thickness is l gt l LS DYNA Version 960 6 23 CONTACT CONTACT Optional Card A Reminder If Card 4 is required then it must go before this optional card Card 4 is required for certain contac
272. able velocity temperature species etc on a node or a set of nodes for the Navier Stokes flow solver Do not use the NODE option in r adaptive problems since the node ID s may change during the adaptive step Card Format Card 1 1 2 3 4 5 6 7 8 w betel L PC ii EN iii EN VARIABLE DESCRIPTION typelD Node ID NID or nodal set ID NSID see SET NODE DOF Applicable degrees of freedom EQ 101 x velocity EQ 102 y velocity EQ 103 z velocity EQ 104 Temperature EQ 107 turbulent kinetic energy EQ 110 turbulent eddy viscosity EQ 121 Species mass fraction 1 EQ 122 Species mass fraction 2 EQ 123 Species mass fraction 3 EQ 124 Species mass fraction 4 EQ 125 Species mass fraction 5 EQ 126 Species mass fraction 6 EQ 127 Species mass fraction 7 EQ 128 Species mass fraction 8 EQ 129 Species mass fraction 9 EQ 130 Species mass fraction 10 EQ 201 x y z velocity EQ 202 x y velocity EQ 203 x z velocity EQ 204 y z velocity LS DYNA Version 960 3 29 BOUNDARY BOUNDARY EQ 301 All species LCID Load curve ID to describe motion value versus time see DEFINE CURVE SF Load curve scale factor default 1 0 Remarks The prescription of all nodal variables in the incompressible flow solver are defined using this keyword It is similar in function to the BOUNDARY PRESCRIBED MOTION OPTION keyword but permits the specifica
273. ace to surface and node to surface type contact options where options 1 and 2 below activate the new contact algorithms The thickness offsets are always included in single surface and constraint method contact types EQ 0 thickness is not considered EQ 1 thickness is considered but rigid bodies are excluded EQ 2 thickness is considered including rigid bodies 6 26 CONTACT LS DYNA Version 960 CONTACT VARIABLE DESCRIPTION SNLOG Disable shooting node logic in thickness offset contact With the shooting node logic enabled the first cycle that a slave node penetrates a master segment that node is moved back to the master surface without applying any contact force EQ 0 logic is enabled default EQ 1 logic is skipped sometimes recommended for metalforming calculations or for contact involving foam materials ISYM Symmetry plane option EQ 0 off EQ 1 do not include faces with normal boundary constraints e g segments of brick elements on a symmetry plane This option is important to retain the correct boundary conditions in the model with symmetry For the _ERODING_ contacts this option may also be defined on card 4 2 Segment searching option EQ 0 search 2D elements shells before 3D elements solids thick shells when locating segments EQ 1 search 3D solids thick shells elements before 2D elements shells when locating segments SLDTHK Optional solid element thickness A nonzero positive val
274. actor allows an increase in the size of the segments May be useful at sharp corners EDGE Edge to edge penetration check for alternate penalty formulation SOFT 2 EQ 0 Check only surface penetrations default GT 0 Check both surface and edge edge penetrations 6 24 CONTACT LS DYNA Version 960 CONTACT Optional Card A continued VARIABLE DESCRIPTION DEPTH Search depth in automatic contact Value of 1 is sufficiently accurate for most crash applications and is much less expensive LS DYNA for improved accuracy sets this value to 2 If zero the default is set to 2 LT 0 IDEPTHI is the load curve ID defining searching depth versus time BSORT Number of cycles between bucket sorts Values of 25 and 100 are recom mended for contact types 4 and 13 SINGLE SURFACE respectively Values of 10 15 are okay for the surface to surface and node to surface contact If zero LS DYNA determines the interval LT 0 IBSORTI load curve ID defining bucket sorting frequency versus time FRCFRQ Number of cycles between contact force updates for penalty contact formulations This option can provide a significant speed up of the contact treatment If used values exceeding 3 or 4 are dangerous Considerable care must be exercised when using this option as this option assumes that contact does not change FRCFRG cycles EQ 0 FRCFRG is set to 1 and force calculations are performed each cycle strongly recommended Remark Setting S
275. actor for acceleration in z direction OMX Scale factor for x angular velocity OMY Scale factor for y angular velocity OMZ Scale factor for z angular velocity Remarks 1 Translational base accelerations allow body forces loads to be imposed on a structure Conceptually base acceleration may be thought of as accelerating the coordinate system in the direction specified and thus the inertial loads acting on the model are of opposite sign For example if a cylinder were fixed to the y z plane and extended in the positive x direction then a positive x direction base acceleration would tend to shorten the cylinder i e create forces acting in the negative x direction Base accelerations are frequently used to impose gravitational loads during dynamic relaxation to initialize the stresses and displacements During the analysis in this latter case the body forces loads are held constant to simulate gravitational loads When imposing loads during dynamic relaxation it is recommended that the load curve slowly ramp up to avoid the excitation of a high frequency response Body force loads due to the angular velocity about an axis are calculated with respect to the deformed configuration and act radially outward from the axis of rotation Torsional effects which arise from changes in angular velocity are neglected with this option The angular velocity is assumed to have the units of radians per unit time The body force density is given at a point
276. ad curve ID for 0 damping moment versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE DLCIDPS Load curve ID for y damping torque versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE LS DYNA Version 960 5 35 CONSTRAINED CONSTRAINED Card 3 of 4 Required for GENERALIZED stiffness Card 3 1 2 3 4 5 6 w fefefe T VARIABLE DESCRIPTION ESPH Elastic stiffness per unit radian for friction and stop angles for rotation See Figure 5 16 If zero friction and stop angles are inactive for rotation FMPH Frictional moment limiting value for rotation If zero friction is inactive for 6 rotation This option may also be thought of as an elastic plastic spring If a negative value is input then the absolute value is taken as the load curve ID defining the yield moment versus 6 rotation See Figure 5 8 EST Elastic stiffness per unit radian for friction and stop angles for rotation See Figure 5 16 If zero friction and stop angles are inactive for rotation FMT Frictional moment limiting value for rotation If zero friction is inactive for rotation This option may also be thought of as an elastic plastic spring If a negative value is input then the absolute value is taken as the load curve ID defining the yield moment versus rotation See Figure 5 16 ESPS Elastic stiffness per unit radian for fricti
277. ad to erroneous results Denotes slide line extension Figure 6 6 Master surface extensions defined automatically by DYNA extensions are updated every time step to remain tangent to ends of master sides of slidelines unless angle of extension is defined in input LS DYNA Version 960 6 65 CONTACT CONTACT Without extension and with improper definition of slide lines slave nodes move down inner and outer walls as shown surface With extension and proper slide line definition elements behave properly Slide line extension Slide lines arrows point to master slides Figure 6 7 Example of slideline extensions helping to provide realistic response 6 66 CONTACT LS DYNA Version 960 CONTROL CONTROL The keyword control cards are optional and can be used to change defaults activate solution options such as mass scaling adaptive remeshing and an implicit solution however it is advisable to define the CONTROL_TERMINATION card The ordering of the control cards in the input file is arbitrary To avoid ambiguities define no more than one control card of each type The following control cards are organized in an alphabetical order CONTROL_ACCURACY CONTROL_ADAPSTEP CONTROL_ADAPTIVE CONTROL_ALE CONTROL_BULK_VISCOSITY CONTROL_CFD_AUTO CONTROL_CFD_GENERAL CONTROL_CFD_MOMENTUM CONTROL_CFD_PRESSURE CONTROL_CFD_TRANSPORT CONTROL_CFD_TURBULENCE CONTROL_COARSEN CONTROL_CONTACT
278. added EQ 2 Belytschko Tsay default MITER Plane stress plasticity option applies to materials 3 18 19 and 24 EQ 1 iterative plasticity with 3 secant iterations default EQ 2 full iterative plasticity EQ 3 radial return noniterative plasticity May lead to false results and has to be used with great care 7 68 CONTROL LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION PROJ Projection method for warping stiffness in the Belytschko Tsay shell and Belytschko Wong Chiang elements see remarks below 0 drill projection EQ 1 full projection ROTASCL Define a scale factor for the rotary shell mass This option is not for general use The rotary inertia for shells is automatically scaled to permit a larger time step size A scale factor other than the default i e unity is not recommended INTGRD Default shell through thickness numerical integration rule 0 Gauss integration If 1 10 integration points are specified the default rule is Gauss integration EQ 1 Lobatto integration If 3 10 integration points are specified the default rule is Lobatto For 2 point integration the Lobatto rule is very inaccurate so Gauss integration is used instead Lobatto integration has an advantage in that the inner and outer integration points are on the shell surfaces LAMSHT For composite shells with material types COMPOSITE DAMAGE and MAT_ENHANCED_COMPOSITE_DAMAGE If this flag is set laminated sh
279. ain at failure Remarks 1 Nodes in the master node set must be given in the order they appear as one moves along the edge of the surface 2 Tie breaks may not cross 3 Tie breaks may be used to tie shell edges together with a failure criterion on the joint If the average volume weighted effective plastic strain in the shell elements adjacent to a node exceeds the specified plastic strain at failure the node is released The default plastic strain at failure is defined for the entire tie break but can be overridden in the slave node set to define a unique failure plastic strain for each node 4 Tie breaks may be used to simulate the effect of failure along a predetermined line such as a seam or structural joint When the failure criterion is reached in the adjoining elements nodes along the slideline will begin to separate As this effect propagates the tie breaks will appear to unzip thus simulating failure of the connection 5 72 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED TIED NODES FAILURE Purpose Define a tied node set with failure based on plastic strain The nodes must be coincident Card Format VARIABLE DESCRIPTION NSID Nodal set ID see SET NODE OPTION EPPF Plastic strain at failure ETYPE Element type for nodal group EQ 0 shell EQ 1 solid element Remarks 1 This feature applies only to deformable plastic three and four noded shell elements and to brick elements using the honey
280. al point n4 see remark 2 below Al First segment attribute see remark 3 below A2 Second segment attribute A3 Third segment attribute A4 Fourth segment attribute NFLS Normal failure stress SFLS Shear failure stress Failure criterion OPTION Option for GENERAL See table below ET B Specified entity Each card must have an option specified See table below 24 16 SET LS DYNA Version 960 SET FORMAT 10 3110 4F10 0 OPTION ENTITIES ATTRIBUTES FUNCTION BOX bl b2 b3 al a2 a3 a4 Generate segments inside box ID bi i 1 2 3 For shell elements one segment per shell is generated For solid elements only those segments wrapping the solid part and pointing outward from the part will be generated BOX SHELL bl b2 b3 al a2 a3 a4 Generate segments inside box ID bi i 1 2 3 The segments are only generated for shell elements One segment per shell is generated BOX SLDIO bl b2 b3 al a2 a3 a4 Generate segments inside box ID bi i 1 2 3 Both exterior segments and inter element segments are generated BOX SOLID bl b2 b3 al a2 a3 a4 Generate segments inside box ID bi i 1 2 3 The segments are only generated for exterior solid elements PART pl p2 p3 al a2 a3 a4 Generate segments of parts pl p2 p3 with attributes al a4 For shell elements one segment per shell is generated For solid elements only those segments wrapping the solid part and pointing outward from the part will be generated PAR
281. all velocities will be reset to zero 29 14 RESTART LS DYNA Version 960 RESTART The VELOCITY RIGID BODY option allows the velocity components of a rigid body to be changed at restart Termination of this input is when the next card is read Card Format 1 2 3 4 5 6 7 8 vine fiw fo ome vm me fo fe fe fe fe fe fe VARIABLE DESCRIPTION PID Part ID of rigid body VX Translational velocity in x direction VY Translational velocity in y direction VZ Translational velocity in z direction VXR Rotational velocity about the x axis VYR Rotational velocity about the y axis VZR Rotational velocity about the z axis Remarks 1 Rotational velocities are defined about the center of mass of the rigid body 2 Rigid bodies not defined in this section will not have their velocities modified The VELOCITY ZERO option resets the velocities to zero at the start of the restart Only the CHANGE VELOCITY ZERO card is required for this option without any further input LS DYNA Version 960 29 15 RESTART RESTART CONTROL DYNAMIC RELAXATION Purpose Define controls for dynamic relaxation Card Format 1 2 3 4 5 6 7 8 reo Fa VARIABLE DESCRIPTION NRCYCK Number of iterations between convergence checks for dynamic relaxation option default 250 DRTOL Convergence tolerance for dynamic relaxation option default 0 001 DRFCTR Dynamic relaxation facto
282. alues on Card 3 in which case abs The contact algorithm for tying spotwelds with torsion SPOTWELD_WITH_TORSION must be used with care Parts that are tied by this option should be subjected to stiffness proportional damping of approximately ten percent i e input a coefficient of 0 10 This can be defined for each part on the DAMPING_PART_STIFFNESS input Stability problems may arise with this option if damping is not used LS DYNA Version 960 6 29 CONTACT CONTACT 3 CONSTRAINT_NODES_TO_SURFACE CONSTRAINT_SURFACE_TO_SURFACE These contact definitions must be used with care The surface and the nodes which are constrained to a surface are not allowed to be used in any other CONSTRAINT_ contact definition If however contact has to be defined from both sides as in sheetmetalforming one of these contact definitions can be aCONSTRAINT_ type the other one could be a standard penalty type such as SURFACE_TO_SURFACE or NODES_TO_SURFACE 4 AIRBAG SINGLE SURFACE AUTOMATIC GENERAL AUTOMATIC GENERAL INTERIOR AUTOMATIC NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE SINGLE SURFACE These contact definitions require thickness to be taken into account for rigid bodies modeled with shell elements Therefore care should be taken to ensure that realistic thicknesses are specified for the rigid body shells A thickness that is too small may result in loss of contact and an
283. an be deleted and those which are added must be placed after the last definition in the previous run The title card is picked up by some of the peripheral LS DYNA codes to aid in post processing VARIABLE DESCRIPTION CID Contact interface ID This must be a unique number NAME Interface descriptor It is suggested that unique descriptions be used 6 6 CONTACT LS DYNA Version 960 CONTACT Card 1 is mandatory for all contact types Card 1 1 2 3 4 5 6 7 8 owes ft fe ona mint f oo VARIABLE DESCRIPTION SSID Slave segment node set ID partset ID part ID or shell element set ID see SET_SEGMENT SET_NODE_OPTION PART SET_PART or SET_SHELL_OPTION For eroding contact use either a part ID or a partset ID 0 all part IDs are included for single surface contact automatic single surface and eroding single surface MSID Master segment set ID partset ID part ID or shell element set ID see SET_SEGMENT SET_NODE_OPTION PART SET_PART or SET_SHELL_OPTION 0 for single surface contact automatic single surface and eroding single surface SSTYP Slave segment or node set type The type must correlate with the number specified for SSID EQ 0 segment set ID for surface to surface contact EQ 1 shell element set ID for surface to surface contact EQ 2 part set ID EQ 3 part ID EQ 4 node set ID for node to surface contact EQ 5 include all for single surface defi
284. an element becomes less than the minimum length as entered on the belt material card the belt is remeshed locally the short element passes through the slipring and reappears on the other side see Figure 12 4 The new unstretched length of el is 1 1 x minimum length Force and strain in e2 and e3 are unchanged force and strain in el are now equal to those in e2 Subsequent slip will pass material from e3 to el This process can continue with several elements passing in turn through the slipring To define a slipring the user identifies the two belt elements which meet at the slipring the friction coefficient and the slipring node The two elements must have a common node coincident with the slipring node No attempt should be made to restrain or constrain the common node for its motion will automatically be constrained to follow the slipring node Typically the slipring node is part of the vehicle body structure and therefore belt elements should not be connected to this node directly but any other feature can be attached including rigid bodies Slipring Element 2 Element 1 Element 1 Element 3 Element 2 Element 3 Before After Figure 12 4 Elements passing through slipring LS DYNA Version 960 12 29 ELEMENT ELEMENT ELEMENT_SHELL_ OPTION Available options include lt BLANK gt THICKNESS BETA Purpose Define three and four noded elements including 3D shells membranes 2D plane stress plane strain and
285. and the outer surface is at 1 Remarks 1 Element formulations 31 and 32 are used exclusively with option which requires ISOLTYP 4 on the CONTROL_SOLUTION card In this case ELFORM 31 is used with INSOL 1 and ELFORM 32 is used with INSOL 3 on the CONTROL GENERAL card Note that selection of the element formulation is automatic based on the value of INSOL for the CFD solver 2 For implicit calculations the following element choices are implemented EQ 1 Hughes Liu EQ 2 Belytschko Tsay default EQ 6 S R Hughes Liu LS DYNA Version 960 EQ 12 EQ 13 EQ 15 EQ 16 17 18 EQ 20 Plane stress x y plane Plane strain x y plane Axisymmetric solid y axis of symmetry volume weighted Fully integrated shell element Fully integrated DKT triangular shell element Taylor 4 node quadrilateral and 3 node triangle linear only Wilson 3 amp 4 node DSE quadrilateral linear only 23 17 SECTION SECTION EQ 31 1 point Eulerian Navier Stokes EQ 32 8 point Eulerian Navier Stokes If another element formulation is requested LS DYNA will substitute one of the above in place of the one chosen 3 The linear elements consist of an assembly of membrane and plate elements The elements have six d o f per node and can therefore be connected to beams or used in complex shell surface intersections All elements possess the required zero energy rigid body modes and have exact con
286. anization is relatively transparent The MOVIE and MPGS database are widely used and will be familiar with users who are currently using these databases Table 9 1 Nodal Quantities Component ID Quantity x y Z displacements X y Z velocities X y Z accelerations Table 9 2 Brick Element Quantities Component ID Quantity X Stress y stress z stress Xy stress yz stress ZX Stress effective plastic strain Table 9 3 Shell and Thick Shell Element Quantities Component ID Quantity midsurface x stress midsurface y stress midsurface z stress midsurface xy stress midsurface yz stress midsurface xz stress midsurface effective plastic strain inner surface x stress inner surface y stress inner surface z stress inner surface xy stress inner surface yz stress inner surface zx stress inner surface effective plastic strain outer surface x stress outer surface y stress outer surface z stress outer surface xy stress outer surface yz stress outer surface zx stress LS DYNA Version 960 9 15 DATABASE DATABASE Table 9 3 Shell and Thick Shell Element Quantities cont Component ID Quantity 21 outer surface effective plastic strain 22 bending moment mxx 4 node shell 23 bending moment myy 4 node shell 24 bending moment mxy 4 node shell 25 shear resultant gxx 4 node shell 26 shear resultant qyy 4 shell 27 normal resultant nxx 4 node shell 28 normal resultant nyy 4 node sh
287. ar segments are defined by repeating the third node 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LOAD SEGMENT 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 A block of solid elements is pressed down onto plane as it moves along that plane This pressure is defined using the LOAD SEGMENT keyword 5 The pressure is applied to the top of the block This top is defined by the faces on top of the appropriate solid elements The faces are defined with segments For example nodes 97 106 107 amp 98 define face on one of the solids and thus one of the faces to apply the 6 pressure too This face is referred to as a single segment 5 The load is defined with load curve number 1 The curve starts at zero ramps to 100 in 0 01 time units and then remains constant However the curve is then scaled by sclo 2 5 Thus raising the load to 250 Note that the load is NOT scaled in the LOAD SEGMENT keyword but could be using the sf variable LOAD SEGMENT Ds DE ea One Dinh DE Os DARD hh 5 lcid sf at ni n2 n3 n4 1 1 00 0 0 97 106 107 98 1 1 00 0 0 106 115 116 107 1 1 00 0 0 98 107 108 99 1 1 00 0 0 107 116 117 108 DEFINE CURVE 5 lcid sidr scla sclo offa offo 0 0 0 2 5 5 5 abscissa ordinate 0 000 0 0 0 010 100 0 0 020 100 0 5 5555555
288. ard under the keyword CONTACT The value defined here will be the default EQ 0 Move nodes to eliminate initial penetrations in the model definition EQ 1 Allow initial penetrations to exist by tracking the initial penetrations Flag to activate the calculation of frictional sliding energy EQ 0 do not calculate EQ 1 calculation frictional energy in contact LS DYNA Version 960 CONTROL Remarks 1 The shell thickness change option must be activated in CONTROL SHELL control input see ISTUPD and a nonzero flag specified for SHLTHK above before the shell thickness changes can be included in the surface to surface contact types An additional flag must be set see THKCHG above if thickness changes are included in the single surface contact algorithms The contact algorithms that include the shell thickness are relatively recent and are now fully optimized and parallelized The searching in these algorithms is considerably more extensive and therefore slightly more expensive 2 In the single surface contacts types SINGLE SURFACE AUTOMATIC_SINGLE_ SURFACE and ERODING SINGLE SURFACE the default contact thickness is taken as the smaller value of the shell thickness or the shell edge lengths between shell nodes 1 2 2 3 and 4 This may create unexpected difficulties if it is the intent to include thickness effects when the in plane shell element dimensions are less than the thickness The default is based on years of experience w
289. ard 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 9 6 7 Card 3 1 2 3 4 5 6 7 8 1 12 AIRBAG LS DYNA Version 960 AIRBAG If the inflator is modeled LCMT 0 define the following card If not define but leave blank Card 4 1 2 3 Define the following card if_and only if CV 0 This option allows temperature dependent heat capacities to be defined See below Card 5 1 2 3 4 3 6 7 8 Define the following card if and only if the POP option is specified Use this option to specify additional criteria for initiating exit flow from the airbag Card 5 1 2 3 4 5 6 7 8 Default LS DYNA Version 960 1 13 AIRBAG AIRBAG VARIABLE CV CP T LCT LCMT TVOL LCDT IABT C23 LCC23 A23 LCA23 CP23 LCCP23 AP23 LCAP23 PE 1 14 AIRBAG DESCRIPTION Heat capacity at constant volume Heat capacity at constant pressure Temperature of input gas For temperature variations a load curve LCT may be defined Optional load curve number defining temperature of input gas versus time This overides columns T Load curve specifying input mass flow rate or tank pressure versus time If the tank volume TVOL is nonzero the curve ID is assumed to be tank pressure versus time If LCMT 0 then the inflator has to be modeled see Card 4 During the dynamic relaxation phase the airbag is ignored unless the curve is flagged to act during dynamic rela
290. ass damping and stiffness matrices in a specified file which follows the formats used in the direct matrix input DMIG of NASTRAN Currently one file format is supported corresponding to the type 6 symmetric matrix in real double precision The damping matrix is optional The following three cards are required for each super element Multiple super elements can be contained in the same file or each superelement may be contained in a separate file The mass matrix must contain the same number of degrees of freedom as the stiffness matrix and in the explicit integration scheme for which this element is implemented the mass matrix must also be positive definite This element is assumed to have an arbitrary number of degrees of freedom and the no assumptions are made about the sparse matrix structure of the matricies that comprise this element The degrees of freedom for this element may consist of generalized coordinates as well as nodal point quantities Card Format I8 Card 1 1 2 3 4 5 6 7 8 Card Format A80 Card 2 Card Format 3A8 Card 3 1 2 3 4 5 6 7 8 12 8 ELEMENT LS DYNA Version 960 VARIABLE EID FILENAME MASS DAMP STIF LS DYNA Version 960 ELEMENT DESCRIPTION Super element ID Path and name of a file which containes the input matrices for this element Name of mass matrix in the file defined by FILENAME This filename should be no more than eight characters to be compatible with NA
291. at 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION REFMAX Maximum number of matrix reformations per time step EQ 0 set to 10 reformations TOL Convergence tolerance for temperature EQ 0 0 set to 1000 machine roundoff DCP Divergence control parameter steady state problems 0 0 lt DCP 1 0 default 1 0 transient problems lt DCP lt 1 0 default 0 5 LS DYNA Version 960 7 77 CONTROL CONTROL CONTROL_THERMAL_SOLVER Purpose Set options for the thermal solution in a thermal only or coupled structural thermal analysis The control card CONTROL_SOLUTION is also required Card Format 1 2 3 4 5 6 7 8 ATYPE PTYPE SOLVER CGTOL EQHEAT FWORK VARIABLE DESCRIPTION ATYPE Thermal analysis type EQ 0 Steady state analysis EQ 1 transient analysis Thermal problem type see CONTROL_THERMAL_NONLINEAR if no zero 0 linear problem EQ 1 nonlinear problem with material properties evaluated at gauss point temperature EQ 2 nonlinear problem with material properties evaluated at element average temperature SOLVER Thermal analysis solver type EQ 1 actol symmetric direct solver EQ 2 dactol nonsymmetric direct solver EQ 3 dscg diagonal scaled conjugate gradient iterative default 4 incomplete choleski conjugate gradient iterative CGTOL Convergence tolerance for solver types 3 and 4 eq 0 default 1 e 04 GPT Number of Gauss points to be used in the s
292. at e Cards and 2 are required for all geometric shapes e Card 3 is required but is dependent upon which shape is specified Optional Card A is required if MOTION is specified 22 2 RIGIDWALL LS DYNA Version 960 RIGIDWALL Card 1 Required for all shape types Card 1 1 2 3 4 5 6 7 8 em feted et blo ME uw ma mcr VARIABLE DESCRIPTION NSID Nodal set ID containing slave nodes see SET NODE OPTION EQ 0 all nodes are slave to rigid wall NSIDEX Nodal set ID containing nodes that exempted as slave nodes see SET _ NODE OPTION BOXID If defined only nodes in box are included as slave nodes to rigid wall LS DYNA Version 960 22 3 RIGIDWALL RIGIDWALL Card 2 Required for all shape types Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XT x coordinate of tail of any outward drawn normal vector n originating on wall tail and terminating in space head see Figure 22 1 YT y coordinate of tail of normal vector n ZT z coordinate of tail of normal vector n XH x coordinate of head of normal vector n YH y coordinate of head of normal vector n ZH z coordinate of head of normal vector n FRIC Interface friction EQ 0 0 frictionless sliding after contact EQ 1 0 stick condition after contact 0 lt FRIC lt 1 Coulomb friction coefficient 22 4 RIGIDWALL LS DYNA Version 960 RIGIDWALL Card 3 Required if FLAT is specified after the keyword A plane with a
293. at the results of accelerometers often show insignificant variations due to the smoothing effect of the accelerometers which are generally attached to nodal rigid bodies The accuracy issues are not new and are inherent in numerical simulations of automotive crash and impact problems where structural bifurcations under compressive loads are common This problem can be easily demonstrated by using a perfectly square thin walled tubular beam of uniform cross section under a compressive load Typically every run on one processor that includes a minor input change 1 element or hourglass formulation will produces dramatically different results in terms of the final shape and likewise if the same problem is again run on a different brand of computer If the same problem is run on multiple processors the results can vary dramatically from run to run WITH NO INPUT CHANGE The problem here is due to the randomness of numerical round off which acts as a trigger in a perfect beam Since summations with CONST 2 occur in a different order from run to run the round off is also random The consistency flag CONST 1 provides for identical results or nearly so whether one two or more processors are used while running in the shared memory parallel SMP mode This is done by requiring that all contributions to global vectors be summed in a precise order independently of the number of processors used When checking for consistent results nodal displacem
294. ates EQ 4 Nonlinear with DFP updates EQ 5 Nonlinear with Davidon updates EQ 6 Nonlinear with BFGS updates arclength EQ 7 Nonlinear with Broyden updates arclength EQ 8 Nonlinear with DFP updates arclength EQ 9 Nonlinear with Davidon updates arclength ILIMIT Iteration limit between automatic stiffness reformations MAXREF Stiffness reformation limit per time step DCTOL Displacement convergence tolerance ECTOL Energy convergence tolerance LSTOL Line search convergence tolerance DNORM Displacement norm for convergence test EQ 1 Increment vs displacement over current step EQ 2 Increment vs total displacement default DIVERG Divergence flag force imbalance increase during equilibrium iterations EQ 1 reform stiffness if divergence detected default EQ 2 ignore divergence ISTIF Initial stiffness formation flag EQ 1 reform stiffness at start of each step default EQ n reform stiffness at start of every n th step NLPRINT Nonlinear solver print flag EQ 1 print iteration information to screen messag d3hsp files EQ 2 print information only to messag d3hsp files default NOTE during execution sense switch nlprint can also be used to toggle this print flag on and off 7 52 CONTROL LS DYNA Version 960 VARIABLE CONTROL DESCRIPTION The following parameters are for use with arc length methods only 6 lt NSOLVR lt 9 ARCCTL ARCDIR ARCLEN ARCMTH ARCDMP Remarks NSOLVR
295. atic time step control and artificial stabilization are activated a multiple step solution will be performed automatically if the single step fails The NSBS option allows a user to skip the single step attempt and proceed directly to a multiple step solution Artificial stabilization must be used for all multiple step solutions The geometric stiffness adds the effect of initial stress to the global stiffness matrix This effect is seen in a piano string whose natural frequency changes with tension Geometric stiffness does not always improve nonlinear convergence so its inclusion is optional 7 50 CONTROL LS DYNA Version 960 CONTROL CONTROL_IMPLICIT_SOLUTION Purpose Define these control cards for an implicit calculation These cards specify whether a linear or nonlinear solution is desired If nonlinear set the parameters to control the implicit nonlinear solution Card 1 Format 1 2 3 4 3 6 7 8 ell pl Optional 2 1 2 3 4 5 6 7 A Optional Card 3 if card 3 is used then card 2 above must also used 1 2 3 4 5 ARCCTL ARCDIR ARCLEN ARCMTH ARCDMP m fo foe fa see remarks below LS DYNA Version 960 7 51 CONTROL CONTROL VARIABLE DESCRIPTION NSOLVR Solution method for implicit analysis EQ 1 Linear EQ 2 Nonlinear with BFGS updates default EQ 3 Nonlinear with Broyden upd
296. ation of state ID 10 12 13 20 21 22 23 0 1 A32 A33 40 41 42 43 50 51 52 53 60 A61 A62 A63 70 71 13 10 LS DYNA Version 960 EOS VARIABLE DESCRIPTION A72 73 14 24 EO Initial internal energy vo Initial relative volume Remarks The ratio of polynomials equation of state defines the pressure as _ F RE FE FE F F E F E 1 a where n 4ifi lt 3 j 0 yaksi n 3ifi23 Po In expanded elements is replaced by F Fj u2 By setting coefficient 1 0 the delta phase pressure modeling for this material will be initiated The code will reset it to 0 0 after setting flags LS DYNA Version 960 13 11 EOS EOS EOS_LINEAR_POLYNOMIAL_WITH_ENERGY_LEAK Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION EOSID Equation of state label CO Cl C2 C3 5 C6 EO Initial internal energy vo Initial relative volume LCID Load curve ID defining the energy deposition rate 13 12 EOS LS DYNA Version 960 EOS Remarks This polynomial equation of state linear in the internal energy per initial volume E is given by p Cy Cpt Cyw Cut Cw JE in which C C C C C and C are user defined constants and 1 FR where V is the relative volume In expanded elements we set the coefficients of u to
297. attached fluid flow The method should not be used to analyze flows where shocks or cavitation are present In practice the method can be successfully applied to a wider class of fluid flow problems than the assumption of inviscid incompressible attached flow would imply Many flows of practical engineering significance have large Reynolds numbers above 1 million For these flows the effects of fluid viscosity are small if the flow remains attached and the assumption of zero viscosity may not be a significant limitation Flow separation does not necessarily invalidate the analysis If well defined separation lines exist on the body then wakes can be attached to these separation lines and reasonable results can be obtained The Prandtl Glauert rule can be used to correct for non zero Mach numbers in a gas so the effects of aerodynamic compressibility can be correctly modeled as long as no shocks are present The BOUNDARY ELEMENT METHOD FLOW card turns on the analysis and is mandatory 3 8 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY ELEMENT METHOD CONTROL Purpose Control the execution time of the boundary element method calculation The CONTROL option is used to control the execution time of the boundary element method calculation and the use of this option is strongly recommended The BEM calculations can easily dominate the total execution time of a LS DYNA run unless the parameters on this card especially DTBEM and or IUPBE
298. available for shell types 1 2 10 and 16 When defining the local coordinate system for the rigid body inertia tensor a local coordinate system ID can be used This simplifies dummy positioning Version 960 1 7 INTRODUCTION INTRODUCTION Prescribing displacements velocities and accelerations is now possible for rigid body nodes One way flow is optional for segmented airbag interactions Pressure time history input for airbag type LINEAR_FLUID can be used An option is available to independently scale system damping by part ID in each of the global directions An option is available to independently scale global system damping in each of the global directions Added option to constrain global DOF along lines parallel with the global axes The keyword is CONSTRAINED_GLOBAL This option is useful for adaptive remeshing Beam end code releases are available see ELEMENT BEAM An initial force can be directly defined for the cable material MAT_CABLE_ DISCRETE_BEAM The specification of slack is not required if this option is used Airbag pop pressure can be activated by accelerometers Termination may now be controlled by contact via TERMINATION_CONTACT Modified shell elements types 8 10 and the warping stiffness option in the Belytschko Tsay shell to ensure orthogonality with rigid body motions in the event that the shell is badly warped This is optional in the Belytschko Tsay shell and the type 10 shell A one point quadrat
299. axis Remarks 1 Ifa node is initialized on more than one input card set then the last set input will determine its velocity unless it is specified on a CHANGE_VELOCITY_NODE 2 Undefined nodes will have their nodal velocities set to zero if a CHANGE VELOCITY definition is encountered in the restart deck 3 If both CHANGE VELOCITY and CHANGE VELOCITY ZERO cards are defined then all velocities will be reset to zero 29 12 RESTART LS DYNA Version 960 RESTART The VELOCITY option allows a new velocity field to be imposed at restart Termination of this input is when the next card is read Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Nodal set ID containing nodes for initial velocity VX Velocity in x direction VY Velocity in y direction VZ Velocity in z direction LS DYNA Version 960 29 13 RESTART RESTART VARIABLE DESCRIPTION VXR Rotational velocity about the x axis VYR Rotational velocity about the y axis VZR Rotational velocity about the z axis Remarks 1 Ifa node is initialized on more than one input card set then the last set input will determine its velocity unless it is specified on a CHANGE VELOCITY NODE card 2 Undefined nodes will have their nodal velocities set to zero if a CHANGE VELOCITY definition is encountered in the restart deck 3 If both CHANGE VELOCITY and CHANGE VELOCITY ZERO cards are defined then
300. ay contain mass from other parts that share nodes See remark 2 below 0 true EQ 1 false SPARSE Use sparse matrix multiply subroutines for the modal stiffness and damping matrices See remark 3 0 false do full matrix multiplies frequently faster EQ 1 true LS DYNA Version 960 7 65 CONTROL CONTROL Remarks 1 As the default the calculation of the relative angles between two coordinate systems is done incrementally This is an approximation in contrast to the total formulation where the angular offsets are computed exactly The disadvantage of the latter approach is that a singularity exists when an offset angle equals 180 degrees For most applications the stop angles prevents this occurrence and LMF 1 should not cause a problem If the determination of the normal modes included the mass from both connected bodies and discrete masses or if there are no connected bodies then the default is preferred When the mass of a given part ID is computed the resulting mass vector includes the mass of all rigid bodies that are merged to the given part ID but does not included discrete masses See the keyword CONSTRAINED_RIGID_BODIES A lumped mass matrix is always assumed Sparse matrix multiplies save a substantial number of operations if the matrix is truly sparse However the overhead will slow the multiplies for densely populated matrices 7 66 CONTROL LS DYNA Version 960 CONTROL CONTROL_SHELL Pur
301. be significantly reduced by setting IUPBEM to a very large number For situations where the structural deformations are modest an intermediate value e g 10 for IUPBEM can be used Define one card 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LWAKE Number of elements in the wake of lifting surfaces Wakes must be defined for all lifting surfaces LS DYNA Version 960 3 9 BOUNDARY BOUNDARY VARIABLE DESCRIPTION DTBEM Time increment between calls to the boundary element method The fluid pressures computed during the previous call to the BEM will continue to be used for subsequent LS DYNA iterations until a time increment of DTBEM has elapsed IUPBEM The number of times the BEM routines are called before the matrix of influence coefficients is recomputed and refactored FARBEM Nondimensional boundary between near field and far field calculation of influence coefficients Remarks 1 Wakes convect with the free stream velocity The number of elements in the wake should be set to provide a total wake length equal to 5 10 times the characteristic streamwise length of the lifting surface to which the wake is attached Note that each wake element has a streamwise length equal to the magnitude of the free stream velocity multiplied by the time increment between calls to the boundary element method routines This time increment is controlled by DTBEM 2 The most accurate results will be obtained with FARBEM set to 5 or more whi
302. below Card 1 Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of the rigid body to which the geometric entity is attached see PART GEOTYP Type of geometric entity EQ 1 plane EQ 2 sphere EQ 3 cylinder EQ 4 ellipsoid EQ 5 torus 6 CAL3D MADYMO Plane see Appendix F 7 CAL3D MADYMO Ellipsoid see Appendix F EQ 8 VDA surface see Appendix I 6 38 CONTACT LS DYNA Version 960 VARIABLE SSID SSTYP SF DF CF INTORD Remark 1 LS DYNA Version 960 CONTACT DESCRIPTION EQ 9 rigid body finite element mesh shells only EQ 10 finite plane EQ 11 load curve defining line as surface profile of axisymmetric rigid bodies Slave set ID see SET NODE OPTION PART or SET_PART Slave set type EQ 0 node set EQ 1 part ID EQ 2 part set ID Penalty scale factor Useful to scale maximized penalty Damping option see description for CONTACT_OPTION EQ 0 no damping GT 0 viscous damping in percent of critical e g 20 for 20 damping EQ n Inl is the load curve ID giving the damping force versus relative normal velocity see remark 1 below Coulomb friction coefficient Assumed to be constant Integration order slaved materials only This option is not available with entity types 8 and 9 where only nodes are checked EQ 0 check nodes only EQ 1 1 point integration over segments EQ 2 2x2 integration EQ 3 3x3
303. bility reasons the scale factor TSSFAC is typically set to a value of 90 default or some smaller value To decrease solution time we desire to use the largest possible stable time step size Values larger than 90 will often lead to instabilities Some comments follow The sound speed in steel and aluminum is approximately 5mm per microsecond therefore if a steel structure is modeled with element sizes of 5mm the computed time step size would be 1 microsecond Elements made from materials with lower sound speeds such as foams will give larger time step sizes Avoid excessively small elements and be aware of the effect of rotational inertia on the time step size in the Belytschko beam element Sound speeds differ for each material for example consider AIR 331 m s WATER 1478 STEEL 5240 TITANIUM 5220 PLEXIGLAS 2598 Model stiff components with rigid bodies not by scaling Young s modulus which can substantially reduce the time step size The altitude of the triangular element should be used to compute the time step size Using the shortest side is okay only if the calculation is closely examined for possible instabilities This is controlled by parameter ISDO LS DYNA Version 960 7 83 CONTROL CONTROL 7 84 CONTROL LS DYNA Version 960 DAMPING DAMPING The Keyword options in this section in alphabetical order are DAMPING GLOBAL DAMPING PART MASS DAMPING PART STIFFNESS DAMPING RELATIVE DAMPING GLOBAL
304. called master nodes related to the solid elements The sliding commences after the rebar debonds The bond between the rebar and concrete is assumed to be elastic perfectly plastic The maximum allowable slip strain is given as SMAX e P max where D is the damage parameter D D Au The shear force acting on area at time n is given as min f GB A GB A Hus LS DYNA Version 960 6 55 CONTACT CONTACT CONTACT 2D OPTIONI OPTION2 OPTIONS Purpose Define a 2 dimensional contact or slide line This option is to be used with 2D solid and shell elements using the plane stress plane strain or axisymmetric formulations see SECTION SHELL OPTION specifies the contact type The following options should be used with deformable materials only i e not rigid SLIDING ONLY TIED SLIDING SLIDING VOIDS since these methods are based on the imposition of constraints The constraint methods may be used with rigid bodies if the rigid body is the master surface and all rigid body motions are prescribed The following options may be used with rigid materials as well PENALTY FRICTION PENALTY AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE AUTOMATIC NODE TO SURFACE AUTOMATIC SURFACE IN CONTINUUM OPTION2 specifies a thermal contact and takes the single option THERMAL Only the AUTOMATIC types SINGLE SURFACE SURFACE TO SURFACE and NODE _ TO SURFACE may be used
305. ccur in many practical applications tis compatible with brick elements because the element is based on a degenerated brick element formulation This compatibility allows many of the efficient and effective techniques developed for the DYNA3D brick elements to be used with this shell element e It includes finite transverse shear strains through the thickness thinning option see Hughes and Carnoy 1981 is also available All shells in our current LS DYNA code must satisfy these desirable traits to at least some extent to be useful in metalforming and crash simulations The major disadvantage of the HL element turned out to be cost related and for this reason within a year of its implementation we looked at the Belytschko Tsay BT shell Belytschko and Tsay 1981 1983 1984 as a more cost effective but possibly less accurate alternative In the BT shell the geometry of the shell is assumed to be perfectly flat the local coordinate system originates at the first node of the connectivity and the co rotational stress update does not use the costly Jaumann stress rotation With these and other simplifications a very cost effective shell was derived which today has become perhaps the most widely used shell elements in both metalforming and crash applications Results generated by the BT shell usually compare favorably with those of the more costly HL shell Triangular shell elements are implemented based on work by Belytschko and co w
306. ce the airbag propellant composition and performance data are company private information it is very difficult to obtain the required information for burn rate modeling However Imperial Chemical Industries ICI Corporation supplied pressure exponent particle geometry packing density heat of reaction and atmospheric pressure burn rate data which allowed us to develop the numerical model presented here for their NaN3 Fe2O3 driver airbag propellant The deflagration model its implementation and the results for the ICI propellant are presented in Hallquist et al 1990 The unreacted propellant and the reaction product equations of state are both of the form p RAY BETEN CT V d where p is pressure in Mbars V is the relative specific volume inverse of relative density is the Gruneisen coefficient is heat capacity in Mbars cc cc K is temperature in K d is the co volume and and are constants Setting A B 0 yields the van der Waal s co volume equation of state The JWL equation of state is generally useful at pressures above several kilobars while the van der Waal s is useful at pressures below that range and above the range for which the perfect gas law holds Of course setting A B d 0 yields the perfect gas law If accurate values of and C plus the correct distribution between cold compression and internal energies are used the calculated temperatures are very reasonable
307. ciated with the bolt part was used to specify that a fully integrated Selectively Reduced solid element formulation be used to totally eliminate the hourglassing elform 2 SECTION SOLID Suse edel oce viu Ge ete ae B sid elform 116 2 PART bolts pid sid mid eosid hgid adpopt 116 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 23 23 SECTION SECTION SECTION_SPH Purpose Define section properties for SPH particles Card Format Card 1 1 2 3 4 6 7 8 VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique CSLH Constant applied to the smoothing length of the particles The default value applies for most problems Values between 1 05 and 1 3 are acceptable Taking a value less than 1 is inadmissible Values larger than 1 3 will increase the computational time The default value is recommended HMIN Scale factor for the minimum smoothing length See Remark 1 HMAX Scale factor for the maximum smoothing length See Remark 1 Remarks l SPH processor LS DYNA uses a variable smoothing length LS DYNA computes the initial smoothing length ho for each SPH part by taking the maximum of the minimum distance between every particle Every particle has its own smoothing length which varies in time according to the following equation 4 ay h tydiv v
308. ckness is taken as the shell thickness if the segment belongs to a shell element or it is taken as 1 20 of its shortest diagonal if the segment belongs to a solid element This option applies to the surface to surface contact algorithms See table 6 1 for contact types and more details EQ 0 check is turned off EQ 1 check is turned on EQ 2 check is on but shortest diagonal is used Birth time contact surface becomes active at this time Death time contact surface is deactivated at this time LS DYNA Version 960 CONTACT Card 3 is mandatory for all contact types Card 3 1 2 3 4 5 6 7 8 element element Default 1 1 thickness thickness 1 1 1 1 VARIABLE DESCRIPTION SFS Scale factor on default slave penalty stiffness see also CONTROL_ CONTACT SFM Scale factor on default master penalty stiffness see also CONTROL_ CONTACT SST Optional thickness for slave surface overrides true thickness This option applies only to contact with shell elements True thickness is the element thickness of the shell elements For the CONTACT_TIED_ options SST and MST below can be defined as negative values which will cause the determination of whether or not a node is tied to depend only on the separation distance relative to the absolute value of these thicknesses More information is given under General Remarks on CONTACT following Optional Card C MST Optional thickness for master surface overrides true thickness
309. comb material The specified nodes are tied together until the average volume weighted plastic strain exceeds the specified value Entire regions of individual shell elements may be tied together unlike the tie breaking shell slidelines The tied nodes are coincident until failure When the volume weighted average of the failure value is reached for a group of constrained nodes the nodes of the elements that exceed the failure value are released to simulate the formation of a crack 2 To use this feature to simulate failure each shell element in the failure region should be generated with unique node numbers that are coincident in space with those of adjacent elements Rather than merging these coincident nodes the CONSTRAINED TIED NODES FAILURE option ties the nodal points together As plastic strain develops and exceeds the failure strain cracks will form and propagate through the mesh 3 Entire regions of individual shell elements may be tied together unlike the CONSTRAINED _ TIE BREAK option This latter option is recommended when the location of failure is known e g as in the plastic covers which hide airbags in automotive structures LS DYNA Version 960 5 73 CONSTRAINED CONSTRAINED 4 When using surfaces of shell elements defined using the CONSTRAINED TIED NODES _ FAILURE option in contact it is best to defined each node in the surface as a slave node with the NODE TO SURFACE contact options If
310. conditions Smug animator database Discrete elements Element data Contact entities Global data Joint forces Material energies MOVIE file family MPGS file family Nastran BDF file Nodal interface forces Nodal force group Nodal point data Rigid body data Resultant interface forces LS DYNA Version 960 VO UNIT i o unit 43 i o unit 44 i o unit 46 i o unit 40 i o unit 36 i o unit 34 i o unit 48 i o unit 35 i o unit 53 i o unit 37 i o unit 50 i o unit 50 i o unit 49 i o unit 38 i o unit 45 i o unit 33 i o unit 47 i o unit 39 FILE NAME ABSTAT AVSFLT BNDOUT nodal forces and energies DEFGEO DEFORC ELOUT GCEOUT GLSTAT JNTFORC MATSUM MOVIEnnn xxx where nnn 001 999 MPGSnnn xxx where nnn 001 999 NASBDF see comment below NCFORC NODFOR NODOUT RBDOUT RCFORC 9 3 DATABASE DATABASE VO UNIT FILE NAME Rigidwall forces i o unit 32 RWFORC Seat belts i o unit 52 SBTOUT Cross section forces i o unit 31 SECFORC Interface energies i o unit 51 SLEOUT SPC reaction forces i o unit 41 SPCFORC SPH element data i o unit 68 SPHOUT Subsystems statistics i o unit 58 SSSTAT Nodal constraint resultants i o unit 42 SWFORC spotwelds rivets Thermal output i o unit 73 TPRINT Tracer particles i o unit 70 TRHIST Output Components for ASCII Files ABSTAT BNDOUT DEFORC volume x y z force 7 force pressure _ nc cem cu internal input mass flow rate output mass flow ra
311. configurations For these configurations the reduction in the number of boundary elements by a factor of 2 will reduce the memory used by the boundary element method by a factor of 4 and will reduce the computer time required to factor the matrix of influence coefficients by a factor of 8 Only 1 plane of symmetry can be defined For the SYMMETRY option define the the following card Define one card 1 2 3 4 5 6 7 8 421141 VARIABLE DESCRIPTION BEMSYM Defines symmetry plane for boundary element method EQ 0 no symmetry plane is defined EQ 1 x 0 isa symmetry plane EQ 2 y 0 isa symmetry plane 3 zz 0 is a symmetry plane LS DYNA Version 960 3 17 BOUNDARY BOUNDARY BOUNDARY ELEMENT METHOD WAKE Purpose To attach wakes to the trailing edges of lifting surfaces Wakes should be attached to boundary elements at the trailing edge of a lifting surface such as a wing propeller blade rudder or diving plane Wakes should also be attached to known separation lines when detached flow is known to exist such as the sharp leading edge of a delata wing at high angles of attack Wakes are required for the correct computation of surface pressures for these situations As described above two segments on opposite sides of a wake should never be used as neighbors For the WAKE option define the the following cards Card Format Cards 1 2 3 The next card terminates the input 1
312. contact merged nodes applied nodal point loads and applied pressure Include all nodes in the attachment node set if their displacements accelerations and velocities are to be written into an ASCII output file Body force loads are applied to the c g of the rigid body Optional 1 2 3 4 2 6 7 8 VARIABLE DESCRIPTION HEADING Heading for the part PID Part identification SECID Section identification defined in the section MID Material identification defined in the MAT section EOSID Equation of state identification defined in the EOS section Nonzero only for solid elements using a an equation of state to compute pressure HGID Hourglass bulk viscosity identification defined in the HOURGLASS Section EQ O default values are used GRAV Part initialization for gravity loading This option initializes hydrostatic pressure in the part due to gravity acting on an overburden material This option applies to brick elements only and must be used with the LOAD_ DENSITY_DEPTH option EQ O all parts initialized EQ 1 only current material initialized ADPOPT Indicate if this part is adapted or not see also CONTROL_ADAPTIVITY 0 no adaptivity EQ 1 H adaptive for 3 D shells 2 R adaptive remeshing for 2 D shells 21 6 PART LS DYNA Version 960 VARIABLE TMID XC YC ZC TM IRCS NODEID IXY IYZ VTX VTY VTZ VRX VRY VRZ LS DYNA Version 960 PART DE
313. d 1 2 3 4 5 6 7 8 I ow HE DEE Low foto of 10 8 DEFINE LS DYNA Version 960 DEFINE VARIABLE DESCRIPTION CID Coordinate system ID A unique number has to be defined XO X coordinate of origin YO Y coordinate of origin ZO Z coordinate of origin XL X coordinate of point on local x axis Y coordinate of point on local x axis ZL Z coordinate of point on local x axis XP X coordinate of point in local x y plane Y coordinate of point in local plane ZP Z coordinate of point in local x y plane Remark 1 The coordinates of the points must be separated by a reasonable distance and not colinear to avoid numerical inaccuracies LS DYNA Version 960 10 9 DEFINE DEFINE DEFINE_COORDINATE_VECTOR Purpose Define a local coordinate system with two vectors see Figure 10 2 The vector cross product xy X x z determines the z axis The y axis is then given by y zxx Card Format Variable Type Default VARIABLE DESCRIPTION CID Coordinate system ID A unique number has to be defined X coordinate on local x axis Origin lies at 0 0 0 YX Y coordinate on local x axis ZX Z coordinate on local x axis XV X coordinate of local x y vector YV Y coordinate of local x y vector ZV Z coordinate of local x y vector Remark 1 These vectors should be separated by a reasonable included angle to avoid numerical inaccuracies z xy y X Origin 0 0
314. d be in the range of first few nonzero frequencies Eigenvectors are written to an auxiliary binary plot database named d3eigv which is automatically created These can be viewed using a postprocessor in the same way as a standard d3plot database The time value associated with each eigenvector plot is the corresponding circular frequency A summary table of eigenvalue results is printed to the eigout file The print control parameter LPRINT and ordering method paramenter ORDER from the CONTROL_IMPLICIT_LINEAR keyword card also affects the Block Shift and Invert Eigensolver LPRINT and LSOLVR affects Subspace Iteration 7 48 CONTROL LS DYNA Version 960 CONTROL CONTROL IMPLICIT GENERAL Purpose Define control parameters for implicit analysis Card Format 1 2 3 4 5 6 7 8 see remarks below VARIABLE DESCRIPTION IMFLAG Implicit Explicit switching flag EQ 0 explicit analysis EQ 1 implicit analysis EQ 2 explicit followed by one implicit step springback analysis DTO Initial time step size for implicit analysis IMFORM Element formulation switching flag EQ 1 switch to fully integrated formulation for implicit springback Recommended for stability 2 retain original element formulation default NSBS Number of steps in nonlinear springback IGS Geometric initial stress stiffness flag EQ 1 include EQ 2 ignore CNSTN Indicator for consistent tangent stiffness EQ 0 do not
315. d body node is used in a spring definition where deflection is limited Constrained boundary conditions on the cards and the BOUNDARY SPC cards must not be used for nodes of springs with deflection limits Discrete elements can be included in implicit applications LS DYNA Version 960 23 9 SECTION SECTION 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 SECTION DISCRETE 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 Note These examples are kg mm ms kN units 5 A translational spring dro 0 is defined to have failure deflection 6 of 25 4 mm fd 25 4 The spring has no dynamic effects or deflection limits thus those parameters are not set SECTION DISCRETE Dr p okie Die nie sese etapa sns stus Ita DB 5 sid dro kd vo cl fd 104 0 25 4 cdl tdl Define a translational spring that is known to have a dynamic crush force 8 equal to 2 5 times the static force at a 15 mm ms deflection rate 6 Additionally the spring is known to be physically constrained to deflect a maximum of 12 5 mm in both tension and compression SECTION DISCRETE ie is SE ME PEE E EP E CMS CR ae sid dro kd vo cl fd 107 0 1 5 15 0 5 5 tdl 12 5 12 5 55555555555555555555555555555555955555555555555555555555555555555555555555555555 5 23 10 SECTION LS DYNA Version 960 SEC
316. d curves This option will stop the motion based on a time dependent constraint The stopper overrides prescribed velocity and displacement boundary conditions for both the master and slaved rigid bodies See Figure 5 19 Card Format Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 A VARIABLE DESCRIPTION PID Part ID of master rigid body see PART LCMAX Load curve ID defining the maximum coordinate or displacement as a function of time See DEFINE CURVE LT 0 Load Curve ID ILCMAXI provides an upper bound for the displacement of the rigid body EQ 0 no limitation of the maximum displacement GT 0 Load Curve ID LCMAX provides an upper bound for the position of the rigid body center of mass LS DYNA Version 960 5 61 CONSTRAINED CONSTRAINED VARIABLE LCMIN PSIDMX PSIDMN LCVMNX DIR TD 5 62 CONSTRAINED DESCRIPTION Load curve ID defining the minimum coordinate or displacement as a function of time See DEFINE CURVE LT 0 Load Curve ID ILCMINI defines a lower bound for the displacement of the rigid body EQ 0 no limitation of the minimum displacement GT 0 Load Curve ID LCMIN defines a lower bound for the position of the rigid body center of mass Optional part set ID of rigid bodies that are slaved in the maximum coordinate direction to the master rigid body In the part set see SET PART OPTION definition the COLUMN option may be used to defined as a
317. d elform shrf qr irid est 111 2 iss itt irr sa 515 6 99660 0 70500 0 170000 0 5 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 23 6 SECTION LS DYNA Version 960 bh t 712 QE SS I2 4 zr b b 3 J l acb i hb 3 i2n EE fit fs 8 8 s t h tt ss t t SECTION _ iy Ber 55 2 t ty A 2001 ht Shear Area pA f Figure 23 1 Properties of beam cross section for several common cross sections LS DYNA Version 960 23 7 SECTION SECTION SECTION_DISCRETE Purpose Defined spring and damper elements for translation and rotation These definitions must correspond with the material type selection for the elements i e MAT SPRING_ and MAT DAMPER Card Format Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique DRO Displacement Rotation Option 0 the material describes a translational spring damper EQ 1 the material describes a torsional spring damper KD Dynamic magnification factor See remarks 1 and 2 below vo Test velocity CL Clearance See remark 3 below FD Failure deflection twist for DRO 1 CDL Deflection twist for DRO 1 limit
318. d enter curve ID 7 44 CONTROL LS DYNA Version 960 CONTROL CONTROL IMPLICIT DYNAMICS Purpose Activate implicit dynamic analysis and define time integration constants Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IMASS Implicit analysis type 0 static analysis EQ 1 dynamic analysis using Newmark time integration EQ 2 dynamic analysis by modal superpostion GAMMA Newmark time integration constant see remarks below BETA Newmark time integration constant Remarks For the dynamic problem the linearized equilibrium equations may be written in the form K x Au F x where lumped mass matrix D damping matrix u x _x nodal displacement vector nodal point velocities at time n 1 nodal point accelerations at time n 1 LS DYNA Version 960 7 45 CONTROL CONTROL The time integration is by the unconditionally stable one step Newmark time integration scheme dil pj pat B 2 sent At 1 y ii yAr x x Au 4 1 Here Ar is the time step size and y are the free parameters of integration For y 2 2 the method reduces to the trapezoidal rule and is energy conserving If B 2 0 numerical damping is induced into the solution leading to loss of energy and momentum 7 46 CONTROL LS DYNA Version 960 CONTROL CONTROL_IMPLI
319. dard load curve LS DYNA Version 960 10 17 DEFINE DEFINE DEFINE_CURVE_TRIM Purpose Define a curve for trimming Also see INTERFACE_SPRINGBACK Card Format 1 2 3 4 5 6 7 8 I ELEILI mL IgM Card 2 3 4 etc defined if and only if TCTYPE 1 Put one pair of points per card 2E20 0 Input is terminated when a card is found 1 2 3 4 5 6 7 8 ELLE T 2 defined if and only if 2 1 2 3 4 5 6 7 8 10 18 DEFINE LS DYNA Version 960 DEFINE VARIABLE DESCRIPTION TCID ID number for trim curve TCTYPE Trim curve type EQ 1 digitized curve provided EQ 2 IGES trim curve TFLG Element removal option EQ 1 remove material outside curve EQ 1 remove material inside curve TDIR ID of vector DEFINE VECTOR giving direction of projection for trim curve see Figure 10 5 EQ 0 default vector 0 0 1 is used Curve is defined in global XY plane and projected onto mesh in global Z direction to define trim line TCTOL Tolerance limiting size of small elements created during trimming see Figure 10 6 LT 0 simple trimming producing jagged edge mesh CX x coordinate of trim curve Defined if and only if TCTYPE 1 CY y coordinate of trim curve Defined if and only if TCTYPE 1 FILENAME Name of IGES database containing trim curve s Defined if and only if TCTYPE 2 Remarks 1 This command in combination with ELEMENT TRIM trims th
320. de adesset een nee EEE ERBE 1 32 MESH GENERATION 2 43 A422 Nissan leere engen 1 32 ESSPOST ALIM eU Mec ae ee PIT 1 33 EXECUTION SPEEDS 1 5 Reb Re sche 1 35 Ne EN Es NEE SE Musee EN 1 36 GENERAL CARD FORMAT a Dea eo er 1 36 FALRBAG cs a een Viste ole Xie ee pra ee ee ee ee 1 1 AIRBAG_OPTIONI_ OPTION2 OPTION3 OPTIONAL NUMERIC ID 1 1 AIRBAG 0 0 0 00000 00 000 1 40 AIRBAG REFERENCE GEOMETRY OPTION 1 42 uU Wo 2 1 ALE MULTI MATERIAL 2 2 YALE REFERENCE SYSTEM CURVE 2 bove re esee Ure 2 4 ALE REFERENCE SYSTEM 2 6 ALE REFERENCE SYSTEM ANODBE 1 2 9 ALE REFERENCE SYSTEM 8 2 11 PATE SMOG THING 2 eee eco ee ced v eco o eR 2 13 LS DYNA Version 960 i TABLE OF CONTENTS KHOUNDATY o Tonor 3 1 BOUNDARY_ACOUSTIC_COUPLING uuanannenenenenenenenenenenennnnnnnnnnenennnnneneenennnnennnn 3 2 BOUNDARY_AMBIENT_EOS 0 ccccccecesecscecscevscscscscscscseecscscscscssececacesesasesesssesseees 3 3 BOUNDARY
321. defined TERMINATION_NODE TERMINATION_BODY TERMINATION_CONTACT LS DYNA Version 960 25 1 TERMINATION TERMINATION TERMINATION NODE Purpose Terminate calculation based on nodal point coordinates The analysis terminates for NODE when the current position of the node specified reaches either the maximum or minimum value stops 1 2 or 3 or picks up force from any contact surface stop 4 Termination by other means than TERMINATION is controlled by the CONTROL TERMINATION control card Note that this type of termination is not active during dynamic relaxation Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Node ID see NODE_OPTION STOP Stop criterion EQ 1 global x direction EQ 2 global y direction EQ 3 global z direction EQ 4 stop if node touches contact surface MAXC Maximum most positive coordinate options 1 2 and 3 above only MINC Minimum most negative coordinate options 1 2 and 3 above only 25 2 TERMINATION LS DYNA Version 960 TERMINATION TERMINATION BODY Purpose Terminate calculation based on rigid body displacements For BODY the analysis terminates when the centre of mass displacement of the rigid body specified reaches either the maximum or minimum value stops 1 2 or 3 or the displacement magnitude of the centre of mass is exceeded stop 4 If more than one condition is input the analysis stops when any of
322. deled with a rigid wall STRESS_INITIALIZATION This is an option available for restart runs In some cases there may be a need for the user to add contacts elements etc which are not available options for standard restart runs A full input containing the additions is needed if this option is invoked upon restart 1 18 INTRODUCTION LS DYNA Version 960 INTRODUCTION SUMMARY OF COMMONLY USED OPTIONS The following table gives a list of the commonly used keywords related by topic Table I 1 Keywords for the most commonly used options Nodes Elements Geometry Discrete Elements Materials composed of Material and Section equation of state and hourglass data Material Sections Discrete sections Equation of state Hourglass Contacts and Defaults for contacts Rigidwalls Definition of contacts Definition of rigidwalls LS DYNA Version 960 NODE ELEMENT_BEAM ELEMENT_SHELL ELEMENT_SOLID ELEMENT_TSHELL ELEMENT_DISCRETE ELEMENT_MASS ELEMENT_SEATBELT_Option MAT_Option SECTION BEAM SECTION SHELL SECTION SOLID SECTION TSHELL SECTION DISCRETE SECTION_SEATBELT EOS_Option CONTROL_HOURGLASS HOURGLASS CONTROL_CONTACT CONTACT Option RIGIDWALL Option 1 19 INTRODUCTION INTRODUCTION Table 1 1 continued Keywords for the most commonly used options NODE Boundary Conditions amp Loadings Constraints and spot welds Output Control Termination Restrain
323. dies will also have their kinetic energy included in the rigid body total Furthermore kinetic energy is computed from nodal velocities in GLSTAT and from element midpoint velocities in MATSUM The PRINT option in the part definition allows some control over the extent of the data that is written into the MATSUM and RBDOUT files If the print option is used the variable PRBF can be defined such that the following numbers take on the meanings EQ 0 default is taken from the keyword CONTROL_OUTPUT EQ 1 write data into RBDOUT file only EQ 2 write data into MATSUM file only EQ 3 do not write data into RBDOUT and MATSUM Also see CONTROL_OUTPUT and PART_PRINT This keyword is also used in the restart phase see RESTART Thus the output interval can be changed when restarting All information in the files except in AVSFLT MOVIE AND MPGS can also be plotted using the post processor LS POST Arbitrary cross plotting of results between ASCII files is easily handled Resultant contact forces reported in RCFORC are averaged over the preceding output interval 9 6 DATABASE LS DYNA Version 960 DATABASE DATABASE_BINARY_OPTION Options for binary output files with the default names given include D3DRLF Dynamic relaxation database D3DUMP Binary output restart files Define output frequency in cycles D3MEAN Averaging interval and statistics level for mean value database D3PART Dt for partial output states See also DATABASE_
324. dinate method XJFP YJFP ZJFP and XJVH YJVH ZJVH unless both NODEI and NODE2 are defined In which case the coordinates of the nodes give by NODEI NODE2 and NODE3 will override XJFP YJFP ZJFP and XJVH YJVH ZJVH The use of nodes is recommended if the airbag system is undergoing rigid body motion The nodes should be attached to the vehicle to allow for the coordinates of the jet to be continuously updated with the motion of the vehicle The jetting option provides a simple model to simulate the real pressure distribution in the airbag during the breakout and early unfolding phase Only the sufaces that are in the line of sight to the virtual origin have an increased pressure applied With the optional load curve LCRJV the pressure distribution with the code can be scaled according to the so called relative jet velocity distribution For passenger side airbags the cone is replaced by a wedge type shape The first and secondary jet focal points define the corners of the wedge and the angle then defines the wedge angle Instead of applying pressure to all surfaces in the line of sight of the virtual origin s a part set can be defined to which the pressure is applied LS DYNA Version 960 1 21 AIRBAG AIRBAG Gaussian profile Virtual origin m Cone center line gt Node 1 Node 2 Hole diameter cendi a large Pressure is applied to sufaces that are in the line of sight to the virtual origin oa tm Seco
325. ding curve This should not be larger than the maximum value used in the loading curve LS DYNA Version 960 6 19 CONTACT CONTACT This Card 4 is mandatory for CONTACT_TIEBREAK_NODES_TO_SURFACE and CONTACT_TIEBREAK_NODES_ONLY Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NFLF Normal failure force Only tensile failure i e tensile normal forces will be considered in the failure criterion SFLF Shear failure force NEN Exponent for normal force MES Exponent for shear force Failure criterion NEN MES Val Me 2 NFLF SFLF Failure is assumed if the left side is larger than 1 fn and fs are the normal and shear interface force Remarks These attributes can be overridden node by node on the SET NODE option cards Both NFLF and SFLF must be defined If failure in only tension or shear is required then set the other failure force to a large value 1E 10 After failure the contact tiebreak nodes to surface behaves as a nodes to surface contact with no thickness offsets no interface tension possible whereas the contact tiebreak nodes only stops acting altogether Prior to failure the two contact types behave identically 6 20 CONTACT LS DYNA Version 960 CONTACT This Card 4 is mandatory for CONTACT_ TIEBREAK_SURFACE_TO_SURFACE Card 4 1 2 3 4 5 6 7 8 1_ VARIABLE DESCRIPTION NFLS Tensile failure stress See remark below SFLS Shear failure stress Fail
326. disjoint tooling meshes the contact option CONTACT FORMING is recommended 5 file adapt rid is left on disk after the adaptive run is completed This file contains the root ID of all elements that are created during the calculation and it does not need to be kept if it is not used in post processing output periods memm N endtime tdeath With adpass 0 the calculation is repeated after adaptive remeshing output periods JA NON endtime tdeath dpfi Er With adpass 1the calculation is not repeated after adaptive remeshing Figure 7 1 At time sbirth the adaptive calculation begins After computing for a time interval adpfreq error norms are computed If ADPASS 0 then the mesh that existed at time tbirth is refined based on the computed error norms With the new mesh the calculation continues to time tbirth 2 x adpfreq where the error norms are again computed The mesh that existed at time tbirth adpfreq is refined and the calculation continues to time tbirth 3 x adpfreq and so on However if ADPASS 1 then the mesh that exist at time thirtht adpfreq is refined and the calculation continues Errors that develop between adaptive remeshing are preserved Generally ADPASS 0 is recommended but this option is considerably more expensive LS DYNA Version 960 7 9 CONTROL CONTROL CONTROL_ALE Purpose Set default control parameters for the Arbitrary Lagrange Eulerian and Euler
327. duce the size of the databases The contents of the D3THDT file are also specified with the DATABASE HISTORY definition It should also be noted in particular that the databases can be considerably reduced for models with rigid bodies containing many elements LS DYNA Version 960 9 7 DATABASE DATABASE Card Format DT CYCL LCDT NPLTC PSETID ISTATS TSTART IAVG Remarks VARIABLE DESCRIPTION DT Time interval between outputs CYCL Output interval in time steps a time step is a cycle For the D3DRFL file a positive number n will cause plot dumps to be written at every n th convergence check interval specified on the CONTROL DYNAMIC RELAXATION card LCDT Optional load curve ID specifying time interval between dumps This option is only available for the D3PLOT D3PART D3THDT and INTFOR files BEAM Option flag for DATABASE BINARY D3PLOT or D3PART EQ 0 Discrete spring and damper elements are added to the D3PLOT or D3PART database where they are display as beam elements The element global X global Y global Z and resultant forces are written to the database EQ 1 No discrete spring and damper elements are added to the D3PLOT or D3PART database This option is useful when translating old LS DYNA input decks to KEYWORD input In older input decks there is no requirement that beam and spring elements have unique ID s and beam elements may be created for the spring and dampers with identical ID s to existing beam elements ca
328. e Remarks If no load curve ID is given then a constant boundary temperature is assumed CMULT is also used to scale the load curve values LS DYNA Version 960 3 47 BOUNDARY BOUNDARY BOUNDARY THERMAL WELD Purpose Define a moving heat source to model welding Only applicable for a coupled thermal structural simulations in which the weld source or workpiece is moving Card 1 Format 1 2 Card 2 Format 1 3 48 BOUNDARY LS DYNA Version 960 VARIABLE BOUNDARY DESCRIPTION PID PTYP NFLAG X0 Y0 Z0 N2ID LCID tx ty tz Remarks Part ID or Part Set ID to which weld source is applied PID type EQ 1 PID defines a single part ID EQ 2 PID defines a part set ID Node ID giving location of weld source EQ 0 location defined by X0 Y0 Z0 below Flag controlling motion of weld source EQ 1 source moves with node NID EQ 2 source is fixed in space at original position of node NID Coordinates of weld source which remains fixed in space optional ignored if NID nonzero above Second node ID for weld beam aiming direction GT 0 beam is aimed from N2ID to NID moves with these nodes EQ 1 beam aiming direction is tx ty tz input on optional card 3 weld pool width weld pool depth in beam aiming direction weld pool forward direction weld pool rearward direction load curve ID for weld energy input rate vs time EQ 0 use constant multiplier value Q curve mult
329. e By default LCID 0 which forces a constant pressure level to be set at the level prescribed by PLEV EQ 0 LCID 0 default 7 21 CONTROL CONTROL CONTROL_CFD_TRANSPORT Purpose Activate the calculation of transport variables and associated solver parameters to be used for the auxiliary scalar transport equations Card 1 is used to activate the auxiliary transport equations and Card 2 is used to set the mass matrix advection and time weighting options Card 3 is used to set the linear solver options such as the maximum iteration count and interval to check the convergence criteria Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 6 7 8 IMASS IADVEC IFCT THETAK THETAA THETAF 5 7 22 CONTROL LS DYNA Version 960 CONTROL Card 3 1 2 3 4 5 6 7 8 ITSOL MAXIT ICHKIT THIST EPS EHG Remarks VARIABLE DESCRIPTION ITEMP Solve the energy equation in terms of temperature 0 No energy equation default EQ 1 Energy equation is solved in terms of temperature NSPEC Activate the solution of NSPEC species transport equations EQ 0 No species equations are solved default EQ NSPEC Solve for NSPEC species Up to 10 species transport equations may be active 0 NSPEC lt 10 IMASS Select the mass matrix formulation to use EQ 0 IMASS 1 default EQ 1 Lumped mass matrix EQ 2 Consistent mass matrix EQ 3 Higher order mass matrix IADVEC Toggle the treatment of advection b
330. e For solid elements six options are available For quadrilateral shell and membrane elements the hourglass control is based on the formulation of Belytschko and Tsay i e options 1 3 are identical and options 4 6 are identical EQ 0 default 1 EQ 1 standard LS DYNA viscous form EQ 2 Flanagan Belytschko viscous form EQ 3 Flanagan Belytschko viscous form with exact volume integration for solid elements EQ 4 Flanagan Belytschko stiffness form EQ 5 Flanagan Belytschko stiffness form with exact volume integration for solid elements EQ 6 Belytschko Bindeman 1993 assumed strain co rotational stiffness form for 2D and 3D solid elements only This form is available for explicit and IMPLICIT solution methods In fact type 6 is mandatory for the implicit options LS DYNA Version 960 14 1 HOURGLASS HOURGLASS VARIABLE DESCRIPTION EQ 8 Applicable to the type 16 fully integrated shell element IHQ 8 activates the warping stiffness for accurate solutions A speed penalty of 2596 is common for this option A discussion of the viscous and stiffness hourglass control for shell elements follows at the end of this section QM Hourglass coefficient Values of QM that exceed 15 for IHQ 6 may cause instabilities The recommended default applies to all options The stiffness forms however can stiffen the response especially if deformations are large and therefore should be used with care For the shell and membrane elements
331. e Provide controls for energy dissipation options Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION HGEN Hourglass energy calculation option This option requires significant additional storage and increases cost by ten percent EQ 1 hourglass energy is not computed default EQ 2 hourglass energy is computed and included in the energy balance The hourglass energies are reported in the ASCII files GLSTAT and MATSUM see DATABASE OPTION RWEN Stonewall energy dissipation option EQ 1 energy dissipation is not computed EQ 2 energy dissipation is computed and included in the energy balance default The stonewall energy dissipation is reported in the ASCII file GLSTAT see DATABASE OPTION SLNTEN Sliding interface energy dissipation option This parameter is always set to 2 if contact is active The option SLNTEN I is not available EQ 1 energy dissipation is not computed EQ 2 energy dissipation is computed and included in the energy balance The sliding interface energy is reported in ASCII files GLSTAT and SLEOUT see DATABASE OPTION RYLEN Rayleigh energy dissipation option damping energy dissipation EQ 1 energy dissipation is not computed default EQ 2 energy dissipation is computed and included in the energy balance The damping energy is reported in ASCII file GLSTAT see DATABASE OPTION LS DYNA Version 960 7 39 CONTROL CONTROL CONTROL_EXPLOSIVE_SHADOW Purpose Compute detonation tim
332. e Set to zero if LCA23 is defined below 1 29 AIRBAG AIRBAG VARIABLE LCA23 CP23 LCCP23 AP23 LCAP23 OPT PVENT NGAS LCIDM LCIDT BLANK INITM 1 30 AIRBAG DESCRIPTION Load curve number defining the vent orifice area which applies to exit hole as a function of absolute pressure A nonzero value for A23 overrides LCA23 Orifice coefficient for leakage fabric porosity Set to zero if LCCP23 is defined below Load curve number defining the orifice coefficient for leakage fabric porosity as a function of time A nonzero value for CP23 overrides LCCP23 Area for leakage fabric porosity Load curve number defining the area for leakage fabric porosity as a function of absolute pressure A nonzero value for AP23 overrides LCAP23 Fabric venting option if nonzero CP23 LCCP23 AP23 and LCAP23 are set to zero EQ 1 Wang Nefske formulas for venting through an orifice are used Blockage is not considered EQ 2 Wang Nefske formulas for venting through an orifice are used Blockage of venting area due to contact is considered EQ 3 Leakage formulas of Graefe Krummheuer and Siejak 1990 are used Blockage is not considered EQ 4 Leakage formulas of Graefe Krummheuer and Siejak 1990 are used Blockage of venting area due to contact is considered EQ 5 Leakage formulas based on flow through a porous media are used Blockage is not considered EQ 6 Leakage formulas based
333. e segment file created in the first run should be specified using the L parameter on the LS DYNA command line Following the above procedure multiple levels of sub modeling are easily accommodated The interface file may contain a multitude of interface definitions so that a single run of a full model can provide enough interface data for many component analyses The interface feature represents a powerful extension of LS DYNA s analysis capabilities KEYWORD Flags LS DYNA that the input deck is akeyword deck To have an effect this must be the very first card in the input deck Alternatively by typing keyword on the execute line keyword input formats are assumed and the KEYWORD is not required If a number is specified on this card after the word KEYWORD it defines the memory size to used in words The memory size can also be set on the command line NOTE THAT THE MEMORY SPECIFIED ON THE KEYWORD CARD OVERRIDES MEMORY SPECIFIED ON THE EXECUTION LINE LOAD This section provides various methods of loading the structure with concentrated point loads distributed pressures body force loads and a variety of thermal loadings This section allows the definition of constitutive constants for all material models available in LS DYNA3D including springs dampers and seat belts The material identifier MID points to the MID on the PART card NODE Define nodal point identifiers and their coordinates PART This ke
334. e I see CONTACT_ OPTION ECP2 Load curve number for Phase II pressure loading reverse see DEFINE CURVE CSP2 Contact surface to determine completion of Phase II see CONTACT_ OPTION NCP2 Percent of nodes in contact to terminate Phase II ERATE Desired strain rate This is the time derivative of the logarithmic strain SCMIN Minimum allowable value for load curve scale factor To maintain a constant strain rate the pressure curve is scaled In the case of a snap through buckling the pressure may be removed completely By putting a value here the pressure will continue to act but at a value given by this scale factor multiplying the pressure curve SCMAX Maximum allowable value for load curve scale factor Generally it is a good idea to put a value here to keep the pressure from going to unreasonable values after full contact has been attained When full contact is achieved the strain rates will approach zero and pressure will go to infinity unless it is limited or the calculation terminates NCYL Number of cycles for monotonic pressure after reversal Remarks l Optionally a second phase can be defined In this second phase a unique set of pressure segments must be defined whose pressure is controlled by load curve 2 During the first phase the pressure segments of load curve 2 are inactive and likewise during the second phase the pressure segments of the first phase are inactive When shell elements are used the complete
335. e and positive quadrants the sign of the relative velocity is used in the table look up 2 Insofar as these ellipsoidal contact surfaces continuous and smooth it may be necessary to specify Coulomb friction values larger than hose typically used with faceted contact surfaces LS DYNA Version 960 6 49 CONTACT CONTACT CONTACT_INTERIOR Purpose Define interior contact for foam brick elements Frequently when foam materials are compressed under high pressure the solid elements used to discretize these materials may invert leading to negative volumes and error terminations In order to keep these elements from inverting it is possible to consider interior contacts within the foam between layers of interior surfaces made up of the faces of the solid elements Since these interior surfaces are generated automatically the part material ID s for the materials of interest are defined here prior to the interface definitions ONLY ONE PART SET ID CAN BE DEFINED Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PSID Part set ID including all parts for which interior contact is desired Three attributes should be defined for the part set Attribute 1 PSF penalty scale factor Default 1 00 Attribute 2 Activation factor F4 Default 0 10 When the crushing of the element reaches F times the initial thickness the contact algorithm begins to act Attribute 3 ED Optional modulus for interior contact stif
336. e conditions LS DYNA Version 960 12 5 ELEMENT ELEMENT applied cannot be subjected to other constraints such as applied displacement velocity acceleration boundary conditions nodal rigid bodies nodal constraint sets or any of the constraint type contact definitions Force type loading conditions and penalty based contact algorithms may be used with this option 3 Please note that this option may lead to nonphysical constraints if the translational degrees of freedom are released but this should not be a problem if the displacements are infinitestimal 4 If the second card is not defined for the resultant beam or if the area A is not defined the properties are taken from the cross section cards see SECTION_BEAM 5 Do not define for discrete beams beam type 6 see SECTION BEAM 6 Define for resultant beam elements only see SECTION BEAM 7 The stress resultants are output in local coordinate system for the beam Stress information is optional and is also output in the local system for the beam 12 6 ELEMENT LS DYNA Version 960 ELEMENT The third node i e the reference node must be unique to each beam element il the coordinate update option is used see CONTROL_OUTPUT Figure 12 1 LS DYNA beam elements Node n3 determines the initial orientation of the cross section LS DYNA Version 960 12 7 ELEMENT ELEMENT ELEMENT_DIRECT_MATRIX_INPUT Purpose Define a an element consisting of m
337. e follower force acts normal to the plane defined by these nodes and a positive follower moment puts a counterclockwise torque about the t axis These actions are depicted in Figure 19 2 3 For shell formulations 14 and 15 the axisymmetric solid elements with area and volume weighting respectively the specified nodal load is per unit length type14 and per radian type 15 W i M V Figure 19 2 Follower force and moment acting on a plane defined by nodes m1 m2 and m3 In this case the load is applied to node m i e m m A positive force acts in the positive t direction and a positive moment puts a counterclockwise torque about the normal vector The positive t direction is found by the cross product t v xw where v and w are vectors as shown 19 20 LOAD LS DYNA Version 960 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LOAD NODE SET A cantilever beam made from shells is loaded on the two end nodes nodes 21 6 22 The load is applied in the y direction dof 2 Load curve number 1 defines the load but is scaled by sf 0 5 in the LOAD NODE SET definition LOAD NODE SET De equi SOG DEAD De 5 nsid dof lcid sf cid mi m2 m3 14 2 1 0 5 SET NODE LIST sid 14 5 nidl nid2 nid3 nid4 nid5 nid6 nid7 nid8 21 22 5 DE
338. e in LS DYNA Also two fully integrated shell elements based on the Hughes and Liu formulation are available in LS DYNA but are rather expensive A much faster fully integrated element which is essentially a fully integrated version of the Belytschko Wong and Chiang element type 16 is a more recent addition and is recommended if fully integrated elements are needed due to its cost effectiveness Three dimensional plane stress constitutive subroutines are implemented for the shell elements which iteratively update the stress tensor such that the stress component normal to the shell midsurface is zero An iterative update is necessary to accurately determine the normal strain component which is necessary to predict thinning One constitutive evaluation is made for each integration point through the shell thickness Zero energy modes in the shell and solid elements are controlled by either an hourglass viscosity or stiffness Eight node thick shell elements are implemented and have been found to perform well in many applications All elements are nearly 100 vectorized All element classes can be included as parts of a rigid body The rigid body formulation is documented in Benson and Hallquist 1986 Rigid body point nodes as well as concentrated masses springs and dashpots can be added to this rigid body Membrane elements can be either defined directly as shell elements with a membrane formulation option or as shell elements with only one point
339. e initial velocities for rotating and translating bodies Caution Rigid body velocities cannot be reinitialized after dynamic relaxation by setting PHASE 1 since rigid body velocities are always restored to the values that existed prior to dynamic relaxation Reinitialization of velocities after dynamic relaxation is only for nodal points of deformable bodies Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 es VARIABLE DESCRIPTION ID Part ID part set ID or node set ID if zero STYP is ignored and all velocities are set STYP Set type EQ 1 part set ID see SET_PART EQ 2 part ID see PART EQ 3 node set ID see SET NODE OMEGA Angular velocity about rotational axis VX Initial translational velocity in global x direction VY Initial translational velocity in global y direction VZ Initial translational velocity in global z direction LS DYNA Version 960 16 23 INITIAL INITIAL VARIABLE DESCRIPTION XC x coordinate on rotational axis YC y coordinate on rotational axis ZC z coordinate on rotational axis NX x direction cosine NY y direction cosine NZ z direction cosine PHASE Flag specifying phase of the analysis the velocities apply to EQ 0 Velocities applied immediately EQ 1 Velocities applied after dynamic relaxation Remarks 1 This generation input must not be used with INITIAL_VELOCITY or INITIAL_ VELOCITY_NODE options 2 T
340. e load curve ID defining the yield moment versus rotation see Figure 5 17 5 40 CONSTRAINED LS DYNA Version 960 CONSTRAINED Card 4 of 4 Required for FLEXION TORSION stiffness Card 4 2 3 SAAL NSABT VARIABLE DESCRIPTION SAAL Stop angle in degrees for a rotation where 0 lt lt Ignored if zero NSABT Stop angle in degrees for negative rotation Ignored if zero PSABT Stop angle in degrees for positive D rotation Ignored if zero Remarks This option simulates a flexion torsion behavior of a joint in a slightly different fashion than with the generalized joint option After the stop angles are reached the torques increase linearly to resist further angular motion using the stiffness values on Card 3 If the stiffness value is too low or zero the stop will be violated The moment resultants generated from the moment versus rotation curve damping moment versus rate of rotation curve and friction are evaluated independently and are added together LS DYNA Version 960 5 41 CONSTRAINED CONSTRAINED Figure 5 17 Flexion torsion joint angles If the initial positions of the local coordinate axes of the two rigid bodies connected by the joint do not coincide the angles and are initialized and torques will develop instantaneously based on the defined load curves The angle is also initialized but no torque will develop about the local axis on which is measured Rather will be mea
341. e number For fluid structure interaction problems it is recommended that the boundary element shells use the same nodes and be coincident with the structural shell elements or the outer face of solid elements which define the surface of the body This approach guarantees that the boundary element segments will move with the surface of the body as it deforms 2 A pressure of PSTATIC is applied uniformly to all segments in the segment set If the body of interest is hollow then PSTATIC should be set to the free stream static pressure minus the pressure on the inside of the body 3 effects of susbsonic compressibility on gas flows be included using a non zero value for MACH The pressures which arise from the fluid flow are increased using the Prandtl Glauert compressibility correction MACH should be set to zero for water or other liquid flows 3 12 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY ELEMENT METHOD NEIGHBOR Purpose Define the neighboring elements for a given boundary element segment The pressure at the surface of a body is determined by the gradient of the doublet distribution on the surface see the LS DYNA Theoretical Manual The Neighbor Array is used to specify how the gradient is computed for each boundary element segment Ordinarily the Neighbor Array is set up automatically by LS DYNA and no user input is required The NEIGHBOR option is provided for those circumstances when the user desires to
342. e requested parts before the job Starts If the command ELEMENT_TRIM does not exist the parts are trimmed after the job is terminated Pre trimming ELEMENT_TRIM DEFINE CURVE TRIM can handle adaptive mesh and post trimming The keyword DEFINE_CURVE_TRIM by itself cannot deal with an adaptive mesh See the detailed proceduce outlined in the Remarks in the Section INTERFACE_SPRINGBACK The trimming tolerance TCTOL limits the size of the smallest element created during trimming A value of 0 0 places no limit on element size A value of 0 5 restricts new elements to be at least half of the size of the parent element A value of 1 0 allows no new elements to be generated only repositioning of existing nodes to lie on the trim curve A negative tolerance value activates simple trimming where entire elements are removed leaving a jagged edge LS DYNA Version 960 10 19 DEFINE DEFINE trim curve local system deformed mesh trim line Figure 10 5 Trimming Orientation Vector The tail T and head H points define a local coordinate system x y z The local x direction is constructed in the Xz plane Trim curve data is input in the x y plane and projected in the z direction onto the deformed mesh to obtain the trim line tol 0 25 default tol 0 01 Figure 10 6 Trimming Tolerance The tolerance limits the si
343. e specified Brittle failure is based on the resultant forces acting on the weld and ductile failure is based on the average plastic strain value of the shell elements which include the spot welded node Spot welds which are connected to massless nodes are automatically deleted in the initialization phase and a warning message is printed in the MESSAG file and the D3HSP file Warning The accelerations of spot welded nodes are output as zero into the various databases but if the acceleration of spotwelded nodes are required use either the CONSTRAINED GENERALIZED WELD or the CONSTRAINED NODAL RIGID BODY input However if the output interval is frequent enough accurate acceleration time histories can be obtained from the velocity time history by differentiation in the post processing phase Card 1 Format Card 1 1 2 3 4 5 6 7 8 5 68 CONSTRAINED LS DYNA Version 960 CONSTRAINED Card 2 Format Define if and only if the option FILTERED FORCE is specified Card 2 1 2 3 4 5 6 7 8 Remarks VARIABLE DESCRIPTION N1 Node ID N2 Node ID SN Normal force at spotweld failure see Remark 2 below SS Shear force at spotweld failure see Remark 2 below N Exponent for normal spotweld force see Remark 2 below M Exponent for shear spotweld force see Remark 2 below TF Failure time for nodal constraint set EP Effective plastic strain at failure NF Number of force vectors stored for filtering TW Time window for filtering Remarks
344. e structure DT Death time Determines when the SPH calculations are stopped IDIM Space dimension for SPH particles 3 for 3D Problems 2 for 2D Problems 2 for 2D Axisymmetric When a value is not specified LS DYNA determines the space dimension automatically by checking the use of 3D 2D or 2D asisymmetric elements LS DYNA Version 960 7 73 CONTROL CONTROL CONTROL_STRUCTURED_ OPTION Options include TERM Purpose Write out a LS DYNA structured input deck for Version 960 The name of this structured file is dyna str This input deck will not support all capabilities that are available in Version 960 As a result some data such as load curve numbers will be output in an internal numbering system If the TERM option is activated termination will occur after the structured input file is written This option is useful in debugging especially if problems occur in reading the input file 7 74 CONTROL LS DYNA Version 960 CONTROL CONTROL_SUBCYCLE Purpose Control time step subcycling This feature is described in the LS DYNA Theoretical Manual Section 20 2 and its use may be detrimental in cases of vectorized computation This keyword activates subcycling The use of mass scaling to preserve a reasonable time step size often works better than subcycling To use mass scaling set the input parameter DT2MS to the negative value of the minimum acceptable time step size See the keyword CONTROL_TIMESTEP LS DYNA Version
345. e system ID s are defined in the DEFINE_COORDINATE_SYSTEM section This local axis is fixed in inertial space 1 e it does not move with the rigid body 2 Nodes 1 M3 must be defined for a follower force or moment The follower force acts normal to the plane defined by these nodes as depicted in Figure 19 2 The positive t direction is found by the cross product t where v and w are vectors as shown follower force is applied at the center of mass A positive follower moment puts a counterclockwise torque about the t axis 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5558 LOAD RIGID BODY 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 From a sheet metal forming example A blank is hit by a punch a binder is used to hold the blank on its sides The rigid holder part 27 is held 6 against the blank using a load applied to the cg of the holder The direction of the load is in the y direction dof 2 but is scaled 5 by sf 1 so that the load is in the correct direction The load 6 is defined by load curve 12 LOAD RIGID BODY Stu beu terse BEE doctos sn iD ur Dita Potala cee oO 5 pid dof lcid sf cid mi m2 m3 27 2 12 51 50 5 5 DEFINE CURVE 5 lcid sidr scla sclo offa offo 12 5 abscissa ordinate 0 000E 00 8 000E 05 1 000E 04 8 000 05 5 5555555555555555555555555555555555555555555555555
346. e updated only in the output databases All loads seen by the rigid body must be applied through this nodal subset or directly to the center of gravity of the rigid body If the rigid body is in contact this set must include all interacting nodes EQ 0 All nodal updates are skipped for this rigid body The null option can be used if the rigid body is fixed in space or if the rigid body does not interact with other parts e g the rigid body is only used for some visual purpose Remarks 1 HEADING default is standard material description e g Material Type 1 In case of SMUG post processing place PSHELL or PBAR or PSOLID in columns 1 8 and Property name in columns 34 41 The local cartesian coordinate system is defined as described in DEFINE_COORDINATE_ VECTOR The local z axis vector is the vector cross product of the x axis and the in plane vector The local y axis vector is finally computed as the vector cross product of the z axis vector and the x axis vector The local coordinate system defined by CID has the advantage that the local system can be defined by nodes in the rigid body which makes repositioning of the rigid body in a preprocessor much easier since the local system moves with the nodal points When specifiying mass properties for a rigid body using the inertia option the mass contributions of deformable bodies to nodes which are shared by the rigid body should be considered as part of the rigid body If the inertia
347. e viewfl or viewfl containing the surface to surface area view factor products 1 must be defined The AjFij products must be stored in this file by row and formatted as 8E10 0 rowl 1 A1F12 eee A F1n row2 2 21 A1F22 eese A2F2n rown AnFnl AnFn2 ee AnFnn The order of segments in the view factor file follow the order the sets are assigned to the boundary radiation definition For example with the following definition 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 BOUNDARY RADIATION SET 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Make boundary enclosure radiation groups 8 and 9 5 BOUNDARY RADIATION SET 15 2 9 10 1 0 1 0 BOUNDARY RADIATION SET 12 2 9 10 1 0 1 0 BOUNDARY RADIATION SET 13 2 8 21 1 0 1 0 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Enclousre radiation group 9 is composed of all the segments in SEGMENT_SET 15 followed by those in SEGMENT_SET 12 the view factors are stored file view_10 Enclosure radiation group 8 is composed of the segment in SEGMENT_SET 13 and reads the view factors from viewfl_21 For the zero group definition the order is segments defined by BOUNDARY_RADIATION_SEGMENT followed by segments defined by BOUNDARY RADIATION SET 3 42 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY SLIDING PLANE Purpose Define a slid
348. e viscous stress can be significant It is not advisable to reduce it by more than an order of magnitude In part the computational efficiency of the Belytschko Lin Tsay and the under integrated Hughes Liu shell elements are derived from their use of one point quadrature in the plane of the element To suppress the hourglass deformation modes that accompany one point quadrature hourglass viscous or stiffness based stresses are added to the physical stresses at the local 14 2 HOURGLASS LS DYNA Version 960 HOURGLASS element level The discussion of the hourglass control that follows pertains to all one point quadrilateral shell and membrane elements in LS DYNA The hourglass shape vector is defined as T where are the element coordinates in the local system at the Ith element node B is the strain displacement matrix and hourglass basis vector is 1 1 1 1 is the basis vector that generates deformation mode that is neglected by one point quadrature In the above equations and the reminder of this subsection the Greek subscripts have a range of 2 e g X ar 9 The hourglass shape vector then operates on the generalized displacements to produce the generalized hourglass strain rates 4 T Vai 5 qo 1 0 43 71904 where the superscripts and W denote membrane bending and warping modes respectively The corresponding hourglass stress rates are then give
349. ected These strain tensors are defined at the inner and outer integration points and are used for post processing only There is no interpolation with this option and the strains are defined in the global cartesian coordinate system The DATABASE EXTENT BINARY flag STRFLG must be set to unity for this option to work Card Format Card 1 Define two cards below one for the inner integration point and the other for the outer integration point respectively Card 2 VARIABLE DESCRIPTION EID Element ID EPSij Define the ij strain component The strains are defined in the GLOBAL cartesian system LS DYNA Version 960 16 9 INITIAL INITIAL INITIAL_STRESS_ BEAM Purpose Initialize stresses and plastic strains in the Hughes Liu beam elements Define as many beams in this section as desired The input is assumed to terminate when a new keyword is detected Card Format Card 1 Define NTPS cards below one per integration point Card 2 81611 51622 51633 SIG12 51623 SIG31 UTE me Pelee de ee Te VARIABLE DESCRIPTION EID Element ID RULE Integration rule type number EQ 1 0 truss element or discrete beam element EQ 2 0 2 x 2 Gauss quadrature default beam EQ 3 0 3 x 3 Gauss quadrature EQ 4 0 3 x 3 Lobatto quadrature EQ 5 0 4 x 4 Gauss quadrature 16 10 INITIAL LS DYNA Version 960 INITIAL VARIABLE DESCRIPTION NPTS Number of integration points
350. ed at places where the hourglass elements fail However it is well known that the elements using more than one point integration are more sensitive to large distortions than one point integrated elements The thick shell element is a shell element with only nodal translations for the eight nodes The assumptions of shell theory are included in a non standard fashion It also uses hourglass control or selective reduced integration This element can be used in place of any four node shell element It is favorably used for shell brick transitions as no additional constraint conditions are LS DYNA Version 960 1 23 INTRODUCTION INTRODUCTION necessary However care has to be taken to know in which direction the shell assumptions are made therefore the numbering of the element is important Seatbelt elements can be separately defined to model seatbelt actions combined with dummy models Separate definitions of seatbelts which are one dimensional elements with accelerometers sensors pretensioners retractors and sliprings are possible The actions of the various seatbelt definitions can also be arbitrarily combined A Z shells B3 AUN uM trusses beams springs lumped masses dampers Figure 1 2 Elements in LS DYNA 1 24 INTRODUCTION LS DYNA Version 960 INTRODUCTION CONTACT IMPACT INTERFACES The three dimensional contact impact algorithm was originally an extension of the NIKE2D Hallquist 1979 two dimensional algor
351. een beam nodes 1 and 2 the average angular velocity of nodes 1 and 2 is used to rotate the triad EQ 1 0 beam node 2 the angular velocity of node 2 rotates triad EQ 2 0 beam node 2 the angular velocity of node 2 rotates triad but the r axis is adjusted to lie along the line between the two beam nodal points This option is not recommended for zero length discrete beams EQ 3 0 beam node 2 the angular velocity of node 2 rotates triad If the magnitude of SCOOR is less than or equal to unity then zero length discrete beams are assumed with infinitestimal separation between the nodes in the deformed state For large separations or nonzero length beams set ISCOORI to 2 or 3 LS DYNA Version 960 23 3 SECTION SECTION VARIABLE TS1 TS2 TT2 NSLOC NTLOC ISS ITT IRR SA VOL 23 4 SECTION DESCRIPTION Beam thickness CST 0 0 2 0 or outer diameter CST 1 0 in s direction at node Note that the thickness defined on the ELEMENT BEAM THICKNESS card overrides the definition give here Beam thickness CST 0 0 2 0 or outer diameter CST 1 0 in s direction at node n Beam thickness CST 0 0 2 0 or inner diameter CST 1 0 in t direction at node nj Beam thickness CST 0 0 2 0 or inner diameter CST 1 0 in t direction at node n Location of reference surface normal to s axis for Hughes Liu beam elements only EQ 1 0 side at s 1 0 EQ 0 0 center EQ 1 0
352. efaults for all parameters Optional Cards A and B not specified default values will be used 5555555555555555555555555555555555555555555555555555555555555555555555555555555 UUY UY Ur oUr UY Ur Ur Ur UY UY Ur UY UY Ur Ur UY Ur UY Ur Ur LS DYNA Version 960 6 35 CONTACT CONTACT 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONTACT SINGLE SURFACE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Create a single surface contact between four parts 28 97 88 and 92 5 create part set with set ID 5 list the four parts 5 in the CONTACT SINGLE SURFACE definition specify 5 sstyp 2 which means the value for ssid is a part set ssid 5 use part set 5 for defining the contact surfaces Additonal contact specifications described below CONTACT SINGLE SURFACE Siete body ERDE iets Sine AS ons Diva ne b ees vr 5 ssid msid sstyp mstyp sboxid mboxid spr mpr 5 2 5 fs fd ve vde penchk bt dt 0 08 0 05 10 20 40 0 5 sfs sfm sst mst sfst sfmt fsf vsf fs 0 08 static coefficient of friction equals 0 08 5 fd 0 05 dynamic coefficient of friction equals 0 05 5 dc 10 exponential decay coefficient helps specify the transition 5 from a static slide to a very dynamic slide vde 20 viscous damping of 20 critical damps out nodal oscillations due to the contact 5 dt 40 0 contact will deactivate a
353. eld constant throughout the analysis dynamically loads the structure Thus the temperature defined can also be seen as a relative temperature to a surrounding or initial temperature Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Node ID T Temperature see remark below Remark 1 temperature range for the constitutive constants in the thermal materials must include the reference temperature of zero If not termination will occur with a temperature out of range error immediately after the execution phase is entered LS DYNA Version 960 19 37 LOAD LOAD LOAD_THERMAL_LOAD_CURVE Purpose Nodal temperatures will be uniform throughout the model and will vary according to a load curve The temperature at time 0 becomes the reference temperature for the thermal material The reference temperature is obtained from the optional curve for dynamic relaxation if this curve is used The load curve option for dynamic relaxation is useful for initializing preloads Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID see DEFINE_CURVE to define temperature versus time LCIDDR An optional load curve ID see DEFINE CURVE to define temperature versus time during the dynamic relaxation phase 19 38 LOAD LS DYNA Version 960 LOAD LOAD THERMAL TOPAZ Purpose Nodal temperatures will be read in from the TOPAZ3D database This file is defined in the EXECUTION SYNTAX see INTRODUCTION LS DYNA Vers
354. elements A completely new mesh is generated which is initialized from the old mesh using a least squares approximation The mesh size is currently based on the value ADPTOL which gives the characteristic element size This option is based on earlier work by Dick and Harris 1992 MAXLVL Maximum number of refinement levels Values of 1 2 3 4 allow a maximum of 1 4 16 64 elements respectively to be created for each original element TBIRTH Birth time at which the adaptive remeshing begins see Figure 7 1 TDEATH Death time at which the adaptive remeshing ends see Figure 7 1 LCADP Adaptive interval is changed as a function of time given by load curve ID LCADP If this option is nonzero the ADPFREQ will be replaced by LCADP The x axis is time and the y axis is the varied adaptive time interval IOFLAG Flag to generate adaptive mesh at exit including NODE ELEMENT SHELL and BOUNDARY_ CONTACT_NODE_ and CON STRAINED_ADAPTIVITY to be saved in the file adapt msh EQ 1 generate adaptive mesh ADPSIZE Minimum element size to be adapted based on element edge length If undefined the edge length limit is ignored ADPASS One or two pass adaptivity flag 0 two pass adaptivity as shown in Figure 7 18 EQ 1 one pass adaptivity as shown in Figure 7 1b IREFLG Uniform refinement level A values of 1 2 3 allow 4 16 64 elements respectively to be created uniformly for each original element
355. ell 29 normal resultant nxy 4 node shell 30 thickness 4 node shell 31 element dependent variable 32 element dependent variable 33 inner surface x strain 34 inner surface y strain 35 inner surface z strain 36 inner surface xy strain 37 inner surface yz strain 38 inner surface zx strain 39 outer surface x strain 40 outer surface y strain 41 outer surface z strain 42 outer surface xy strain 43 outer surface yz strain 44 outer surface zx strain 45 internal energy 46 midsuface effective stress 47 inner surface effective stress 48 outer surface effective stress 49 midsurface max principal strain 50 through thickness strain 51 midsurface min principal strain 52 lower surface effective strain 53 lower surface max principal strain 54 through thickness strain 55 lower surface min principal strain 56 lower surface effective strain 57 upper surface max principal strain 58 through thickness strain 59 upper surface min principal strain 60 upper surface effective strain Table 9 4 Beam Element Quantities Component ID Quantity x force resultant y force resultant z force resultant x moment resultant y moment resultant z moment resultant 9 16 DATABASE LS DYNA Version 960 DATABASE For the BINARY option the following cards apply Card Format Card 1 1 2 3 4 5 6 7 8 Variable NEIPS MAXINT STRFLG SIGFLG EPSFLG RLTFLG ENGFLG Default Remarks Card 2 1 2 3 4 Variable IP DCOMP
356. ell theory is used Lamination theory is applied to correct for the assumption of a uniform constant shear strain through the thickness of the shell Unless this correction is applied the stiffness of the shell can be grossly incorrect if there are drastic differences in the elastic constants from ply to ply especially for sandwich type shells Generally without this correction the results are too stiff For the discrete Kirchhoff shell elements which do not consider transverse shear this option is ignored EQ 0 do not update shear corrections EQ 1 activate laminated shell theory Remarks 1 The drill projection is used in the addition of warping stiffness to the Belytschko Tsay and the Belytschko Wong Chiang shell elements This projection generally works well and is very efficient but to quote Belytschko and Leviathan The shortcoming of the drill projection is that even elements that are invariant to rigid body rotation will strain under rigid body rotation if the drill projection is applied On one hand the excessive flexibility rendered by the 1 point quadrature shell element is corrected by the drill projection but on the other hand the element becomes too stiff due to loss of the rigid body rotation invariance under the same drill projection They later went on to add in the conclusions The projection of only the drill rotations is very efficient and hardly increases the computation time so it is recommended for most cases
357. emarks below Set to 1 to dump strain tensors for solid shell and thick shell elements for plotting by LS POST and ASCII file ELOUT For shell and thick shell elements two tensors are written one at the innermost and one at the outermost integration point For solid elements a single strain tensor is written Flag for including stress tensor in the shell LS DYNA database EQ 1 include default EQ 2 exclude Flag for including the effective plastic strains in the shell LS DYNA database EQ 1 include default EQ 2 exclude Flag for including stress resultants in the shell LS DYNA database EQ 1 include default EQ 2 exclude Flag for including internal energy and thickness in the LS DYNA database EQ 1 include default EQ 2 exclude Orthotropic and anisotropic material stress output in local coordinate system for shells and thick shells Currently this option does not apply to solid elements with the exception of material MAT_COMPOSITE_DAMAGE EQ 0 global EQ 1 local Every plot state for d3plot database is written to a separate file This option will limit the database to 100 states EQ 0 more than one state can be on each plotfile EQ 1 one state only on each plotfile Number of beam integration points for output This option does not apply to beams that use a resultant formulation Data compression to eliminate rigid body data EQ 1 off default no data compression EQ 2 on LS DYNA
358. ements retractors sliprings pretensioners and sensors must exist in both files and will be initialized Materials which are not initialized will have no initial deformations or stresses However if initialized and non initialized materials have nodes in common the nodes will be moved by the initialized material causing a sudden strain in the non initialized material This effect could give rise to sudden spikes in loading Points to note are Time and output intervals are continuous with job i e the time is not reset to zero Don t try to use the restart part of the input to change anything since this will be overwritten by the new input file e Usually the complete input file part of job2 inl will be copied from jobl inf with the required alterations We again mention that there is no need to update the nodal coordinates since the deformed shapes of the initialized materials will be carried forward from jobl Completely new databases will be generated with the time offset VDA IGES DATABASES VDA surfaces are surfaces of geometric entities which are given in the form of polynomials The format of these surfaces is as defined by the German automobile and supplier industry in the VDA guidelines VDA 1987 The advantage of using VDA surfaces is twofold First the problem of meshing the surface of the geometric entities is avoided and second smooth surfaces can be achieved which are very important in metalforming With sm
359. ements of parts p1 p2 p3 previously added will be excluded b1 b2 b3 b4 b5 b6 b7 Elements inside boxes bl b2 will be included DBOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes b1 b2 previously added will be excluded 24 4 SET LS DYNA Version 960 SET SET DISCRETE OPTION Available options include BLANK GENERATE GENERAL The last option GENERATE will generate a block of discrete element ID s between a starting ID and an ending ID An arbitrary number of blocks can be specified to define the set Purpose Define a set of discrete elements Card Format Card 1 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION none The next card terminates the input 1 2 3 4 5 6 7 8 LS DYNA Version 960 24 5 SET SET Cards 2 3 4 OPTIONZGENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIBEG BIEND B2BEG B2END B3BEG B3END B4BEG B4END Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options ALL ELEM DELEM PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID First discrete element K2 Second discrete element KNUM Last discrete element BNBEG First discrete element ID in block n BNEND Last discrete element ID in block N All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all
360. en the last set input will determine its velocity However if the nodal velocity is also specified on a INITIAL_VELOCITY _ NODE card then the velocity specification on this card will be used 3 For rigid bodies initial velocities given in PART_INERTIA will overwrite generated initial velocities 4 Nodes which belong to rigid bodies must have motion consistent with the translational and rotational velocity of the rigid body During initialization the rigid body translational and rotational rigid body momentum s are computed based on the prescribed nodal velocities From this rigid body motion the velocities of the nodal points are computed and reset to the new values These new values may or may not be the same as the values prescribed for the node LS DYNA Version 960 16 21 INITIAL INITIAL INITIAL_VELOCITY_NODE Purpose Define initial nodal point velocities for a node Card Format 1 2 3 4 5 6 7 8 vine fw vm me me fo fe fete fe fe fe VARIABLE DESCRIPTION NID Node ID Initial translational velocity in x direction VY Initial translational velocity in y direction VZ Initial translational velocity in z direction VXR Initial rotational velocity about the x axis VYR Initial rotational velocity about the y axis VZR Initial rotational velocity about the z axis See remark on INITIAL_ VELOCITY card 16 22 INITIAL LS DYNA Version 960 INITIAL INITIAL_VELOCITY_GENERATION Purpose Defin
361. enclosure group zero FILE NO is ignored and view factors are read from viewfl The same file may be used for different radiation enclosure group definitions RFLCID Load curve ID for radiation factor f see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value REMULT LT 0 function versus temperature RFMULT Curve multiplier for f see DEFINE CURVE TILCID Load curve ID for versus time see DEFINE CURVE EQ 0 use constant multiplier TIMULT TIMULT Curve multiplier for Too see DEFINE CURVE SELCID Load curve ID for surface emissivity see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value SEMULT LT 0 function versus temperature SEMULT Curve multiplier for surface emissivity see DEFINE CURVE Remarks A radiation boundary condition is calculated using a radiant heat transfer coefficient Set 4 T Too where hy is a radiant heat transfer coefficient defined as h f T T XT T The exchange factor F is a characterization of the effect of the system geometry emissivity and reflectivity on the capability of radiative transport between surfaces The radiation boundary condition data cards require specification of the product f Fo and T for the boundary surface The Stefan Boltzmann constant must be defined for radiation in enclosure type 2 See CONTROL_THERMAL_SOLVER LS DYNA Version 960 3 41 BOUNDARY BOUNDARY A file with the nam
362. ents This option requires that each reference node is unique to the beam EQ 0 no update EQ 1 update Averaged accelerations from velocities in file and the time history database file d3thdt EQ 0 no average default EQ 1 averaged between output intervals Output interval for interface file At see INTRODUCTION Execution syntax Print initial time step sizes for all elements on the first cycle EQ 0 100 elements with the smallest time step sizes are printed EQ 1 the governing time step sizes for each element are printed Problem status report interval steps to the D3HSP printed output file This flag is ignored if the GLSTAT file is written see DATABASE GLSTAT Number of time steps interval for flushing I O buffers The default value is 5000 If the I O buffers are not emptied and an abnormal termination occurs the output files can be incomplete The I O buffers for restart files are emptied automatically whenever a restart file is written so these files are not affected by this option Default print flag for RBDOUT and MATSUM files This flag defines the default value for the print flag which can be defined in the part definition section see PART This option is meant to reduce the file sizes by eliminating data which is not of interest EQ 0 write part data into both MATSUM and RBDOUT EQ 1 write data into RBDOUT file only EQ 2 write data into MATSUM file only EQ 3 do not write dat
363. ents or element stresses should be compared The NODOUT and ELOUT files should be digit to digit identical However the GLSTAT SECFORC and many of the other ASCH files will not be identical since the quantities in these files are summed in parallel for efficiency reasons and the ordering of summation operations are not enforced The biggest drawback of this option is the CPU cost penalty which is at least 15 percent if PARA 0 and is much less if PARA 1 and 2 or more processors are used Unless the PARA flag is on for non vector processors parallel scaling is adversely affected The consistency flag does not apply to MPP parallel 3 PARA flag will cause the force assembly for the consistency option to be performed in parallel for the shared memory parallel option Better scaling will be obtained with the consistency option but with more memory usage However the single processing speed is slightly diminished The logic for parallelization cannot be efficiently vectorized and is not recommended for vector computers since is will degrade CPU performance This option does not apply to MPP parallel If PARA CONST 0 and NUMRHS NCPU the force assembly by default is done in parallel LS DYNA Version 960 7 63 CONTROL CONTROL CONTROL_REMESHING Purpose Control the element size for three dimensional adaptivity for solids element This commands control the size of the elements on the surface of the solid part Card Format 1 2 3 4 5 6
364. ents which belong to shell elements are properly oriented i e the outward normal vector of the segment based on the right hand rule relative to the segment numbering must point to the opposing contact surface consequently automatic contact generation should be avoided for parts composed of shell elements unless automatic generation is used on the slave side of a nodes to surface interface 6 18 CONTACT LS DYNA Version 960 CONTACT This Card 4 is mandatory for CONTACT_RIGID_NODES_TO_RIGID_BODY CONTACT_RIGID_BODY_ONE_WAY_TO_RIGID_BODY CONTACT_RIGID_BODY_TWO_WAY_TO_RIGID_BODY Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID giving force versus penetation behavior for RIGID_ contact See also the definition of FCM below FCM Force calculation method for RIGID_contact EQ 1 Load curve gives total normal force on surface versus maximum penetration of any node RIGID_BODY_ONE_WAY only EQ 2 Load curve gives normal force on each node versus penetration of node through the surface all RIGID_contact types EQ 3 Load curve gives normal pressure versus penetration of node through the surface RIGID_BODY_TWO_WAY and RIGID_BODY_ ONE_WAY only EQ 4 Load curve gives total normal force versus maximum soft penetration In this case the force will be followed based on the original penetration point RIGID_BODY_ONE_WAY only US Unloading stiffness for RIGID_contact The default is to unload along the loa
365. epends on the orientation of the shell elements as shown in Figure 19 3 Pressure loads will be discontinued if IVIDI Do normal vector to the shell element lt OFF where is the Only elements inside the box with part ID SSID are considered If no ID is given all elements of part ID SSID are included When the active list of elements are updated elements outside the box will no longer have pressure applied i e the current configuration is always used Curve ID defining the mask This curve gives x y pairs of points in a local coordinate system defined by the vector ID VID2 Generally the curve should form a closed loop i e the first point is identical to the last point and the curve should be flagged as a DATTYP 1 curve in the DEFINE CURVE section If no curve ID is given all elements of part ID PID are included with the exception of those deleted by the box The mask works like the trimming option i e see DEFINE CURVE TRIM and Figure 10 4 Vector ID used to project the masking curve onto the surface of part ID PID The origin of this vector determines the origin of the local system that the coordinates of the PID are transformed into prior to determining the pressure distribution in the lcoal system This curve must be defined if LCIDM is nonzero If 0 elements whose center falls inside the projected curve are considered If 1 elements whose center falls outside the projected curve are considered Number
366. er 9 13 DATABASE DATABASE DATABASE_EXTENT_OPTION Options include AVS BINARY MOVIE MPGS SSSTAT Purpose Specify output database to be written Binary applies to the data written to the D3PLOT D3PART and D3THDT files See DATABASE BINARY OPTION For the AVS MPGS and MOVIE options the following cards apply Define as many cards as necessary The created MPGS and MOVIE databases consist of a geometry file and one file for each output database Card Format VARIABLE DESCRIPTION VTYPE Variable type EQ 0 node EQ 1 brick EQ 2 beam EQ 3 shell EQ 4 thick shell COMP Component ID For the corresponding VTYPE integer components from the following tables can be chosen VTYPE EQ 0 Table 9 1 VTYPE EQ 1 Table 9 2 VTYPE EQ 2 not supported VTYPE EQ 3 Table 9 3 VTYPE EQ 4 not supported 9 14 DATABASE LS DYNA Version 960 DATABASE Remarks The AVS database consists of a title card then a control card defining the number of nodes brick like elements beam elements shell elements and the number of nodal vectors NV written for each output interval The next NV lines consist of character strings that describe the nodal vectors Nodal coordinates and element connectivities follow For each state the solution time is written followed by the data requested below The last word in the file is the number of states We recommend creating this file and examining its contents since the org
367. er X X coordinate Y y coordinate Z Z coordinate TC Translational Constraint EQ 0 no constraints EQ 1 constrained x displacement EQ 2 constrained y displacement EQ 3 constrained z displacement EQ 4 constrained x and y displacements EQ 5 constrained y and z displacements EQ 6 constrained z and x displacements EQ 7 constrained x y and z displacements 20 2 NODE LS DYNA Version 960 VARIABLE DESCRIPTION RC Rotational constraint 0 no constraints EQ 1 constrained x rotation EQ 2 constrained y rotation EQ 3 constrained z rotation EQ 4 constrained x and y rotations EQ 5 constrained y and z rotations EQ 6 constrained z and x rotations EQ 7 constrained x y and z rotations Remarks 1 Boundary conditions can also be defined on nodal points in a local or global system by using the keyword BOUNDARY SPC For other possibilities also see the CONSTRAINED keyword section of the manual 2 node without an element or a mass attached to it will be assigned a very small amount of mass and rotary inertia Generally massless nodes should not cause any problems but in rare cases may create stability problems if these massless nodes interact with the structure Warning messages are printed when massless nodes are found Also massless nodes are used with rigid bodies to place joints see CONSTRAINED EXTRA NODES OPTION and CONSTRAINED NODAL RIGID BODY LS DYNA Version 960 20
368. erm given by q Q a if 0 q 0 if amp 20 where Q and Q are dimensionless input constants which default to 1 5 and 06 respectively and is a characteristic length given as the square root of the area in two dimensions and as the cube root of the volume in three a is the local sound speed Q defaults to 1 5 and Q defaults to 06 See Chapter 18 in Theoretical Manual for more details 7 12 CONTROL LS DYNA Version 960 CONTROL CONTROL_CFD_AUTO Purpose Set the time step control options for the Navier Stokes flow solver CONTROL_CFD_GENERAL is used in conjunction with this keyword to control the flow solver time integration options Card Format Default VARIABLE DESCRIPTION IAUTO Set the time step control type 0 IAUTO 1 for fixed time step size EQ 1 Fixed time step based on DTINIT see CONTROL_CFD_GENERAL default EQ 2 Time step based on CFL stability for INSOL 3 1 EQ 3 Automatic time step selection based on a second order Adams Bashforth predictor with a trapezoidal rule corrector EPSDT Set the tolerance for local truncation error in time EQ 0 EPSDT 1 0e 3 default DTSF Set the maximum time step scale factor that may be applied at any given time step This puts the upper limit on the amount that the time step can be increased during any given time step EQ 0 DTSF 1 25 default DTMAX Set the upper limit on the time step size This value puts a ceiling on how far
369. ermine correct 5 displacement from contact displacements DFSCL Scale factor for load curve Default 1 0 This factor scales load curve ID LCIDRF above LS DYNA Version 960 6 15 CONTACT CONTACT VARIABLE DESCRIPTION NUMINT Number of equally spaced integration points along the draw bead EQ 0 Internally calculated based on element size of elements that interact with draw bead This is necessary for the correct calculation of the restraining forces More integration points may increase the accuracy since the force is applied more evenly along the bead Remarks The draw bead is defined by a consecutive list of slave nodes that lie along the draw bead For straight draw beads only two nodes need to be defined i e one at each end but for curved beads sufficient nodes are required to define the curvature of the bead geometry The integration points along the bead are equally spaced and are independent of the nodal spacing used in the definition of the draw bead By using the capability of tying extra nodes to rigid bodies see CONSTRAINED_EXTRA_NODES_OPTION the draw bead nodal points do not need to belong to the element connectivities of the die and binder The blank makes up the master surface IT IS HIGHLY RECOMMENDED TO DEFINE A BOXID AROUND THE DRAWBEAD TO LIMIT THE SIZE OF THE MASTER SURFACE CONSIDERED FOR THE DRAW BEAD THIS WILL SUBSTANTIALLY REDUCE COST AND MEMORY REQUIREMENTS D depth of draw bead 2 gt
370. ero analysis EQ 0 0 DT2MS remains unchanged LCTM Load curve ID that limits maximum time step size EQ 0 LCTM remains unchanged Remark 1 This a reduced version of the CONTROL_TIMESTEP used in the initial analysis The dummy fields are included to maintain compatability If using free format input then a 0 0 should be entered for the dummy values LS DYNA Version 960 29 19 RESTART RESTART DAMPING GLOBAL Purpose Define mass weigthed nodal damping that applies globally to the deformable nodes Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID which specifies node system damping EQ n system damping is given by load curve n The damping force applied to each node is f d t mv where d t is defined by load curve VALDMP System damping constant d this option is bypassed if the load curve number defined above is nonzero 29 20 RESTART LS DYNA Version 960 RESTART DATABASE OPTION Options for ASCII files include If a file is not specified in the restart deck then the output interval for the file will remain unchanged SECFORC Cross section forces RWFORC Wall forces NODOUT Nodal point data ELOUT Element data GLSTAT Global data DEFORC Discrete elements MATSUM Material energies NCFORC Nodal interface forces RCFORC Resultant interface forces DEFGEO Deformed geometry file SPCFORC Set dt for spc reaction forces SWFORC Nodal constraint reaction forces spotwelds
371. es in explosive elements for which there is no direct line of sight If this control card is missing the lighting time for an explosive element is computed using the distance from the center of the element to the nearest detonation point L the detonation velocity D and the lighting time for the detonator t L t 2f 4 D The detonation velocity for this option is taken from the element whose lighting time is computed and does not account for the possiblities that the detonation wave may travel through other explosives with different detonation velocities or that the line of sight may pass outside of the explosive material If this control card is present the lighting time is based on the shortest distance through the explosive material If inert obstacles exist within the explosive material the lighting time will account for the extra time required for the detonation wave to travel around the obstacles The lighting times also automatically accounts for variations in the detonation velocity if different explosives are used No additional input is required for this control option This option works for two and three dimensional solid elements Also see INITIAL DETONATION and MAT HIGH EXPLOSIVE 7 40 CONTROL LS DYNA Version 960 CONTROL CONTROL_HOURGLASS_ OPTION One option is available 936 which switches the hourglass formulation so that it is identical to that used in version 936 of LS DYNA The modification in the h
372. es require separate scale factors STX Scale factor on global x translational damping forces LS DYNA Version 960 8 3 DAMPING DAMPING VARIABLE DESCRIPTION STY Scale factor on global y translational damping forces STZ Scale factor on global z translational damping forces SRX Scale factor on global x rotational damping moments SRY Scale factor on global y rotational damping moments SRZ Scale factor on global z rotational damping moments Remarks Mass weighted damping damps all motions including rigid body motions For high frequency oscillatory motion stiffness weighted damping may be preferred With mass proportional system damping the acceleration is computed as a M F F damp where M is the diagonal mass matrix P is the external load vector F is the internal load vector and is the force vector due to system damping This latter vector is defined as damp E uo D mv The best damping constant for the system is usually based on the critical damping factor for the lowest frequency mode of interest Therefore D 20 nin is recommended where the natural frequency given in radians per unit time is generally taken as the fundamental frequency of the structure The damping is applied to both translational and rotational degrees of freedom The component scale factors can be used to limit which global components see damping forces Energy dissipated by through mass weighted damping is
373. es where point loads are to be applied or where springs may be attached 4 Defining a lumped mass at a particular location and so on The coordinates of the extra nodes are updated according to the rigid body motion LS DYNA Version 960 5 3 CONSTRAINED CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 CONSTRAINED EXTRA NODES NODE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Rigidly attach nodes 285 and 4576 to part 14 Part 14 MUST be a rigid body CONSTRAINED EXTRA NODES NODE PE EN DES EPI OUR IER oO EE Pas be he nae 28 pid nid 14 285 14 4576 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 365595949599595959595095959495995959498990959190990959590989 595909 9 0959590998 CONSTRAINED EXTRA NODES SET 365595949599595919999995959495995959498990959190990959590989959 909 9 0959590958 Rigidly attach all nodes in set 4 to part 17 Part 17 MUST be a rigid body In this example four nodes from a deformable body are attached to rigid body 17 as a means of joining the two parts CONSTRAINED EXTRA NODES SET Law Bohn Qe hie Bis Bes Ak Sens Dar 5 pid nsid 17 4 SET NODE LIST sid 4 5 nidl nid2 nid3 nid4 nid5 nid7 nid8 665 778 896 827 5 55555555555555555555555555555555555555555
374. eturn into the retractor if sufficient material is reeled in during unloading Elements e2 e3 and e4 are initially inside the retractor which is paying out material into element el When the retractor has fed L into el where Lerit fed length 1 1 x minimum length minimum length defined on belt material input fed length defined on retractor input element e2 emerges with an unstretched length of 1 1 x minimum length the unstretched length of element el is reduced by the same amount The force and strain in el are unchanged in e2 they are set equal to those in el The retractor now pays out material into e2 If no elements are inside the retractor e2 can continue to extend as more material is fed into it As the retractor pulls in the belt for example during initial tightening if the unstretched length of the mouth element becomes less than the minimum length the element is taken into the retractor To define a retractor the user enters the retractor node the mouth element into which belt material will be fed el in Figure 11 2 up to 4 sensors which can trigger unlocking a time delay a payout delay optional load and unload curve numbers and the fed length The 12 20 ELEMENT LS DYNA Version 960 ELEMENT retractor node is typically part of the vehicle structure belt elements should not be connected to this node directly but any other feature can be attached including rigid bodies The mouth ele
375. etween explicit with balancing tensor diffusivity BTD or fully implicit EQ 0 IADVEC 10 for forward Euler with BTD default EQ 1 IADVEC 0 for foward Euler without BTD EQ 10 forward Euler with BTD EQ 40 fully implicit with simplified trapezoid rule IFCT Toggle the use of the advective flux limiting advection scheme EQ 0 IFCT 1 default EQ 1 Advective flux limiting is on EQ 1 Advective flux limiting is off THETAK Time weighting for viscous diffusion terms Valid values are 0 0 lt 1 with for second order accuracy in time EQ 0 THETAK 0 5 default LS DYNA Version 960 7 23 CONTROL CONTROL VARIABLE THETAA THETAF ITSOL MAXIT ICHKIT IWRT IHIST EPS IHG EHG Remarks DESCRIPTION Time weighting for advection terms Time weighting for body forces and boundary conditions Valid values are 0X0 lt 1 with for second order accuracy in time EQ 0 THETAF 0 5 default Set the equation solver type for the transport equations EQ 0 ITSOL 20 default EQ 20 Jacobi preconditioned conjugate gradient method EQ 30 Jacobi preconditioned conjugate gradient squared method default when IADVEC 40 Set the maximum number of iterations for the iterative equation solver EQ 0 MAXIT 100 default Set the interval to check the convergence criteria for the iterative equation solver EQ 0 ICHKIT 2 default Activate the output of diagnostic information fr
376. etween time delay ending and retractor locking a length value LLCID Load curve for loading Pull out Force see Figure 12 3 ULCID Load curve for unloading Pull out Force see Figure 12 3 LFED Fed length see explanation below Remarks 1 The retractor node should not be on any belt elements The element defined should have one node coincident with the retractor node but should not be inside the retractor 25 At least one sensor should be defined SA The first point of the load curve should be 0 Tmin Tmin is the minimum tension All subsequent tension values should be greater than Tmin 4 The unloading curve should start at zero tension and increase monotonically i e no segments of negative or zero slope Retractors allow belt material to be paid out into a belt element Retractors operate in one of two regimes unlocked when the belt material is paid out or reeled in under constant tension and locked when a user defined force pullout relationship applies The retractor is initially unlocked and the following sequence of events must occur for it to become locked l E CEN 3 Any one of up to four sensors must be triggered The sensors are described below Then a user defined time delay occurs Then a user defined length of belt must be paid out optional Then the retractor locks and once locked it remains locked In the unlocked regime the retractor attempts to apply a constant tension to the belt
377. face data for many component analyses The interface feature represents a powerful extension of LS DYNA s analysis capability CAPACITY Storage allocation is dynamic The only limit that exists on the number of boundary condition cards number of material cards number of pressure cards etc is the capacity of the computer Typical LS DYNA calculations may have 10 000 to 500 000 elements Memory allocation is dynamic and can be controlled during execution SENSE SWITCH CONTROLS The status of an in progress LS DYNA simulation can be determined by using the sense switch On UNIX versions this is accomplished by first typing a Control C This sends an interrupt to LS DYNA which is trapped and the user is prompted to input the sense switch code LS DYNA has nine terminal sense switch controls that are tabulated below Type Response Swi A restart file is written and LS DYNA terminates SW2 LS DYNA responds with time and cycle numbers SW3 A restart file is written and LS DYNA continues Swa4 A plot state is written and LS DYNA continues SWS Enter interactive graphics phase and real time visualization SW7 Turn off real time visualization Sws Interactive 2D rezoner for solid elements and real time visualization 5 9 Turn off real time visualization for option SW8 SWA Flush ASCII file buffers 1 26 INTRODUCTION LS DYNA Version 960 INTRODUCTION Type Response Implicit Mode Only Iprint Enable Disab
378. factor shell element formulation numerical damping and termination time DAMPING Defines damping either globally or by part identifier DATABASE This keyword with a combination of options can be used for controlling the output of ASCII databases and binary files output by LS DYNA With this keyword the frequency of writing the various databases can be determined LS DYNA Version 960 1 15 INTRODUCTION INTRODUCTION DEFINE This section allows the user to define curves for loading constitutive behaviors etc boxes to limit the geometric extent of certain inputs local coordinate systems vectors and orientation vectors specific to spring and damper elements Items defined in this section are referenced by their identifiers throughout the input For example a coordinate system identifier is sometimes used on the BOUNDARY cards and load curves are used on the AIRBAG cards DEFORMABLE_TO_RIGID This section allows the user to switch parts that are defined as deformable to rigid at the start of the analysis This capability provides a cost efficient method for simulating events such as rollover events While the vehicle is rotating the computation cost can be reduced significantly by switching deformable parts that are not expected to deform to rigid parts Just before the vehicle comes in contact with ground the analysis can be stopped and restarted with the part switched back to deformable ELEMENT Define identifiers and con
379. ff amp 1000000 fctmas amp 1 0000 ideoff amp 1000000 ilctmf amp 1000000 fcttim amp 1 0000 LS DYNA Version 960 dy amp dz amp 0 0 0 0 dy amp dz amp 1220 1 0 dy amp dz amp 0 0 1 0 dy amp dz amp 0 0 0 0 dy amp dz amp 0 0 0 0 idpoff amp idmoff amp 0 0 fctlen amp fcttem amp 1 00 1 0 idpoff amp idmoff amp 1000000 1000000 fctlen amp fcttem amp 1 00 1 0 px amp 0 00 idsoff amp 0 incout amp 1 idsoff amp 1000000 incout amp 1 py amp 0 00 iddoff amp 0 iddoff amp 1000000 DEFINE pz amp angle amp 0 0 45 00 iddoff amp 0 iddoff amp 1000000 10 27 DEFINE DEFINE 5 tranid amp 2000 INCLUDE TRANSFORM dummy k Sidnoff amp 2000000 idroff amp 2000000 fctmas amp 1 0000 tranid amp 3000 END 10 28 DEFINE ideoff amp 2000000 ilctmf amp 2000000 fcttim amp 1 0000 idpoff amp idmoff 2000000 fctlen amp 1 00 amp 2000000 fcttem amp ls 0 idsoff amp 2000000 incout amp 1 iddoff amp 2000000 iddoff amp 2000000 LS DYNA Version 960 DEFINE DEFINE VECTOR Purpose Define a vector by defining the coordinates of two points Card Format 1 2 3 4 MIL me fo fo fo To VARIABLE DESCRIPTION VID Vector ID XT X coordinate of tail of vector YT Y coordinate of tail of vector ZT Z coordinate of tail of vector XH X coordinate of
380. fined by the product of the specified thickness in the s direction and the thickness in the t direction See also ICST below and Figure 17 1 Standard cross section type ICST If this type is nonzero then NIP and the relative area above should be input as zero See the discussion following the input description Figures 17 3a and 17 3b EQ 1 W section EQ 2 C section EQ 3 Angle section EQ 4 T section EQ 5 Rectangular tubing EQ 6 Z section EQ 7 Trapezoidal section w flange width tr flange thickness d depth tw web thickness Sref location of reference surface normal to s for the Hughes Liu beam only This option is only useful if the beam is connected to a shell or another beam on its outer surface see also SECTION BEAM tref location of reference surface normal to t for the Hughes Liu beam only This option is only useful if the beam is connected to a shell or another beam on its outer surface see also SECTION BEAM Normalized s coordinate of integration point 1 lt s lt 1 Normalized t coordinate of integration point 1 lt t lt 1 Weighting factor A i e the area associated with the integration point ri divided by actual cross sectional area A see Figure 17 2 LS DYNA Version 960 INTEGRATION Thicknesses defined on beam cross section cards Relative Area Figure 17 1 Definition of relative area for user defined integration rule 2 f EN
381. finite size or with an infinite size can be defined see Figure 22 1 The vector m is computed as the vector cross product n X l The origin which is the tail of the normal vector is the corner point of the finite size plane Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XHEV x coordinate of head of edge vector l see Figure 22 1 YHEV y coordinate of head of edge vector 1 ZHEV z coordinate of head of edge vector 1 LENL Length of l edge A zero value defines an infinite size plane LENM Length of m edge A zero value defines an infinite size plane LS DYNA Version 960 22 5 RIGIDWALL RIGIDWALL Card 3 Required if PRISM is specified after the keyword The description of the definition of a plane with finite size is enhanced by an additional length in the direction negative to n see Figure 22 1 Card 3 1 2 3 4 5 6 7 8 fet et et et ete VARIABLE DESCRIPTION XHEV x coordinate of head of edge vector 1 see Figure 22 1 YHEV y coordinate of head of edge vector 1 ZHEV z coordinate of head of edge vector 1 LENL Length of l edge A zero valure defines an infinite size plane LENM Length of m edge A zero valure defines an infinite size plane LENP Length of prism in the direction negative to n see Figure 22 1 22 6 RIGIDWALL LS DYNA Version 960 RIGIDWALL Card 3 Required if CYLINDER is specified after the keyword The tail of n specifies the top plane of the cylinder The length is defined in the direction negative
382. fness Remarks The interior penalty is determined by the formula 2 K SLSFAC PSF Volume Min Thickness where SLSFAC is the value specified on the CONTROL CONTACT volume is the volume of the brick element E is a consitutive modulus and min thickness is approximately the thickness of the solid element through its thinnest dimension If ED is defined above the interior penalty is then given instead by 6 50 CONTACT LS DYNA Version 960 CONTACT 2 _ Volume ED Min Thickness where the scaling factors are ignored Generally ED should be taken as the locking modulus specified for the foam constitutive model Caution should be observed when using this option since if the time step size is too large an instability may result The time step size is not affected by the use of interior contact LS DYNA Version 960 6 51 CONTACT CONTACT CONTACT_RIGID_SURFACE Purpose Define rigid surface contact The purpose of rigid surface contact is to model large rigid surfaces e g road surfaces with nodal points and segments that require little storage and are written out at the beginning of the binary databases The rigid surface motion which can be optionally prescribed is defined by a displacement vector which is written with each output state The nodal points defining the rigid surface must be defined in the NODE_RIGID_SURFACE section of this manual These rigid nodal points do not contribute deg
383. for through thickness integration The latter choice includes transverse shear stiffness and may be inappropriate For airbag material a special fully integrated three and four node membrane element is available Two different beam types are available a stress resultant beam and a beam with cross section integration at one point along the axis The cross section integration allows for a more general definition of arbitrarily shaped cross sections taking into account material nonlinearities Spring and damper elements can be translational or rotational Many behavior options can be defined e g arbitrary nonlinear behavior including locking and separation Solid elements in LS DYNA may be defined using from 4 to 8 nodes The standard elements are based on linear shape functions and use one point integration and hourglass control A selective reduced integrated called fully integrated 8 node solid element is available for situations when the hourglass control fails Also two additional solid elements a 4 noded tetrahedron and an 8 noded hexahedron with nodal rotational degrees of freedom are implemented based on the idea of Allman 1984 to replace the nodal midside translational degrees of freedom of the elements with quadratic shape functions by corresponding nodal rotations at the corner nodes The latter elements which do not need hourglass control require many numerical operations compared to the hourglass controlled elements and should be us
384. force vector due to system damping This latter vector is defined as damp n Ion D mv The best damping constant for the system is usually based on the critical damping factor for the lowest frequency mode of interest Therefore D 2O nin is recommended where the natural frequency given in radians per unit time is generally taken as the fundamental frequency of the structure Note that this damping applies to both translational and rotational degrees of freedom Energy dissipated by through mass weighted damping is reported as system damping energy in the ASCII file GLSTAT This energy is computed whenever system damping is active 8 2 DAMPING LS DYNA Version 960 DAMPING DAMPING_ PART MASS Purpose Define mass weighted damping by part ID Parts may be either rigid or deformable In rigid bodies the damping forces and moments act at the center of mass Card Format 1 2 3 4 5 6 7 8 Card Format This card is optional and is read if and only if FLAG 1 If this card is not read STX STY STZ SRX SRY and SRZ default to unity Card 2 1 2 3 4 5 6 7 8 sm ey ow w fe fe fe fe fete VARIABLE DESCRIPTION PID Part ID see PART LCID Load curve ID which specifies system damping for parts SF Scale factor for load curve This allows a simple modification of the load curve values FLAG Set this flag to unity if the global components of the damping forc
385. friction Fpending Figure 6 2 Draw bead contact model defines a resisting force as a function of draw bead displacement The friction force is computed from the normal force in the draw bead and the given friction coefficient 6 16 CONTACT LS DYNA Version 960 CONTACT This Card 4 is mandatory for CONTACT_ ERODING_NODES_TO_SURFACE CONTACT_ ERODING_SINGLE_SURFACE CONTACT_ ERODING_SURFACE_TO_SURFACE Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ISYM Symmetry plane option EQ 0 off EQ 1 do not include faces with normal boundary constraints e g segments of brick elements on a symmetry plane This option is important to retain the correct boundary conditions in the model with symmetry EROSOP Erosion Interior node option EQ 0 only exterior boundary information is saved EQ 1 storage is allocated so that eroding contact can occur Otherwise no contact is assumed after erosion of the corresponding element IADJ Adjacent material treatment for solid elements EQ 0 solid element faces are included only for free boundaries EQ 1 solid element faces are included if they are on the boundary of the material subset This option also allows the erosion within a body and the subsequent treatment of contact LS DYNA Version 960 6 17 CONTACT CONTACT This Card 4 is mandatory for CONTACT_NODES_TO_SURFACE_INTERFERENCE CONTACT ONE WAY SURFACE TO SURFACE INTERFERENCE CONTACT SURFACE TO SURFACE INTERFERENCE
386. gins If the pressure is relieved the reaction rate decreases and can go to zero This feature is important for short duration partial decomposition reactions If the pressure is maintained the fraction reacted eventually reaches one and the material is completely converted to product molecules The deflagration front rates of advance through the propellant calculated by this model for several propellants are quite close to the experimentally observed burn rate versus pressure curves To obtain good agreement with experimental deflagration data the model requires an accurate description of the unreacted propellant equation of state either an analytical fit to experimental compression data or an estimated fit based on previous experience with similar materials This is also true for the reaction products equation of state The more experimental burn rate pressure production and energy delivery data available the better the form and constants in the reaction rate equation can be determined Therefore the equations used in the burn subroutine for the pressure in the unreacted propellant R3 T P Rl e P 2 FO 4 V FRER where Vy and the relative volume and temperature respectively of the unreacted propellant The relative density is obviously the inverse of the relative volume The pressure Pp in the reaction products is given by a V CCRIT As the reaction proceeds the unreacted and
387. gn a specific reference system type Lagrangian Eulerian or ALE to a set of nodes Card Format Card 1 1 2 3 4 5 6 7 8 IER ae on fom EHEIENENENENENENEN Card 2 1 2 3 4 VARIABLE DESCRIPTION SID Set ID STYPE Set type 0 part set EQ 1 part EQ 2 node set EQ 3 segment set 2 6 ALE LS DYNA Version 960 VARIABLE PRTYPE PRID BCTRAN BCEXP BCROT LS DYNA Version 960 ALE DESCRIPTION Reference system type EQ 0 Eulerian EQ 1 Lagrangian EQ 2 Normal ALE mesh smoothing EQ 3 Prescribed motion following load curves see ALE REFERENCE SYSTEM CURVE EQ 4 Automatic mesh motion following mass weighted average velocity in ALE mesh EQ 5 Automatic mesh motion following coordinate system defined by three user defined nodes see REFERENCE SYSEM NODE EQ 6 Switching in time between different reference system types see ALE REFERENCE SYSEM SWITCH EQ 7 Automatic mesh expansion in order to enclose up to twelve user defined nodes see REFERENCE SYSEM NODE ID of switch list node group or curve group PRTYPE 3 5 6 or 7 Translational constraints PRTYPE 3 4 5 and 7 EQ 0 no constraints EQ 1 constrained x translation EQ 2 constrained y translation EQ 3 constrained z translation EQ 4 constrained x and y translation EQ 5 constrained y and z ranslation EQ 6 constrained z and x translation EQ 7 constrained
388. gth units CFT Conversion factor milliseconds per LS DYNA time unit CFP Conversion factor psi per LS DYNA pressure unit Remarks 1 A minimum of two load curves even if unreferenced must be present in the model LS DYNA Version 960 19 5 LOAD LOAD LOAD_BODY_OPTION Options incude for base accelerations X Y Z for angular velocities RX RY RZ and to specifiy a part set PARTS Purpose Define body force loads due to a prescribed base acceleration or angular velocity using global axes directions This data applies to all nodes in the complete problem unless a part subset is specified via the _ BODY PARTS keyword If a part subset is defined then all nodal points belonging to the subset will have body forces applied parts specified via the LOAD BODY PARTS keyword apply to the options X Y Z RX RY and RZ above i e different part sets may not apply to different options Only one part set is expected Note This option applies nodal forces i e it cannot be used to prescribe translational or rotational motion Two keyword definitions are needed to apply body loads on a subset of parts LOAD BODY X and LOAD BODY PARTS Card Format for options X Y Z RX RY and RZ 1 2 3 4 5 6 7 8 oe fe fe fet et ef ef 19 6 LOAD LS DYNA Version 960 LOAD Card Format for option PARTS 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID see DEFINE_CURVE SF Load curve scale facto
389. gure 2 1 This simple constraint which ensures that a slave node remains on a straight line between two master nodes is sometimes necessary during ALE smoothing 2 14 ALB LS DYNA Version 960 nodes BOUNDARY BOUNDARY The keyword BOUNDARY provides a way of defining imposed motions on boundary The keyword control cards in this section are defined in alphabetical order BOUNDARY_ACOUSTIC_COUPLING BOUNDARY_AMBIENT_EOS BOUNDARY_CONVECTION_OPTION BOUNDARY_CYCLIC BOUNDARY_ELEMENT_METHOD_OPTION BOUNDARY_FLUX_OPTION BOUNDARY_NON_REFLECTING BOUNDARY NON REFLECTING 2D BOU N N BOUNDARY PRESCRIBED MOTION OPTION NDARY PRESSURE OUTFLOW OPTION N BOUNDARY RADIATION OPTION BOUNDARY SLIDING PLANE BOUNDARY SPC OPTION BOUNDARY SYMMETRY FAILURE BOUNDARY TEMPERATURE OPTION BOUNDARY USA SURFACE LS DYNA Version 960 3 1 BOUNDARY BOUNDARY BOUNDARY ACOUSTIC COUPLING Purpose Define a segment set for acoustic coupling The segments should define the surface of a shell or solid structural element This option allows for acoustic elements type 8 solid elements to couple on either one side of a shell or solid element structure or both sides of a shell structure The nodal points of the shell segments and those on either side of the segments must be coincident If the fluid exists on just one side of the segment and if the nodes are merged no input is necessary and input data in this section
390. h other joints such as the revolute or cylindrical joints LS DYNA Version 960 5 29 CONSTRAINED CONSTRAINED Figure 5 10 Gear joint Nodal pairs 1 3 and 2 4 define axes that are orthogonal to the gears Nodal pairs 1 5 and 2 6 define vectors in the plane of the gears The ratio 18 1 specified Figure 5 11 Rack and pinion joint Nodal pair 1 3 defines a vector that is orthogonal to the plane of the gear Nodal pair 1 5 is a vector in the plane of the gear Nodal pair 2 4 defines the direction of travel for the second body The value h is specified 5 30 CONSTRAINED LS DYNA Version 960 CONSTRAINED Figure 5 12 Constant velocity joint Nodal pairs 1 3 and 2 4 define an axes for the constant angular velocity and nodal pairs 1 5 are orthogonal vectors Here nodal points 1 and 2 must be coincident E Figure 5 13 Pulley joint Nodal pairs 1 3 and 2 4 define axes that are orthogonal to the pulleys Nodal pairs 1 5 and 2 6 define vectors in the plane of the pulleys The R ne ratio is specified 1 LS DYNA Version 960 5 31 CONSTRAINED CONSTRAINED Figure 5 14 Screw joint The second body translates in response to the spin of the first body Nodal pairs 1 3 and 2 4 lie along the same axis and nodal pairs 1 5 and 2 6 Me h Be are orthogonal vectors The helix ratio is specified 5 555555555555555555555555555555555555555555555555555555555555555555555555555
391. havior is contained within the discrete analysis model 3 With the two optional switches the influence of reflecting waves can be studied 3 24 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY NON REFLECTING 2D Purpose Define a non reflecting boundary This option applies to continuum domains modeled with two dimensional solid elements in the xy plane as indefinite domains are usually not modeled For geomechanical problems this option is important for limiting the size of the models Card Format Remarks VARIABLE DESCRIPTION NSID Node set ID see SSET NODE See Figure 3 7 Remarks 1 Non reflecting boundaries defined with this keyword are only used with two dimensional solid elements in either plane strain or axisymmetric geometries Boundaries are defined as a sequential string of nodes moving counterclockwise around the boundary 2 Non reflecting boundaries are used on the exterior boundaries of an analysis model of an infinite domain such as a half space to prevent artificial stress wave reflections generated at the model boundaries form reentering the model and contaminating the results Internally LS DYNA computes an impedance matching function for all non reflecting boundary segments based on an assumption of linear material behavior Thus the finite element mesh should be constructed so that all significant nonlinear behavior in contained within the discrete analysis model LS DYNA Version 960 3 25 BOUNDARY
392. he MASTER surface are DAI FSF Coulomb friction scale factor DA2 VSF Viscous friction scale factor For airbags see AIRBAG a time delay DA1 T1 can be defined before pressure begins to act on a segment along with a time delay DA2 T2 before full pressure is applied to the segment default T2 T1 and for the constraint option 2 To define a triangular segment make n4 equal to n3 3 The default segment attributes can be overridden on these cards otherwise Al DAl etc 24 18 SET LS DYNA Version 960 SET SET SHELL OPTION Available options include LIST COLUMN LIST GENERATE GENERAL The last option will generate a block of shell ID s between a starting shell ID number and an ending ID number An arbitrary number of blocks can be specified to define the shell set Purpose Define a set of shell elements with optional identical or unique attributes Card Format Card 2 3 4 OPTION LIST The next card terminates the input 1 2 3 4 5 6 7 8 EID1 EID2 EID3 EID4 EID5 EID6 EID7 EID8 LS DYNA Version 960 24 19 SET SET Card 2 3 4 OPTIONZCOLUMN The next card terminates the input 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION LIST_GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIBEG BIEND B2BEG B2END B3BEG B3END B4BEG B4END Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a
393. he control volume If holes are detected they are assumed to be covered by planar surfaces Vsca and Psca allow for unit system changes from the inflator to the finite element model There are two sets of volume and pressure used for each control volume First the finite element model computes a volume Vfemodel and applies a pressure The thermodynamics of a control volume may be computed in a different unit system thus there is a separate volume Vevolume and pressure Pcyolume which are used for integrating the differential equations for the control volume The conversion is as follows 22 V remodel 71 Voi P PaP fe model cvolume Damping can be applied to the structure enclosing a control volume by using a mass weighted damping formula d m D v Ve where F is the damping force m is the nodal mass v is the velocity for a node is the mass weighted average velocity of the structure enclosing the control volume and D is the damping factor An alternative separate damping is based on the stagnation pressure concept The stagnation pressure is roughly the maximum pressure on a flat plate oriented normal to a steady state flow field The stagnation pressure is defined as p where V is the normal velocity of the control volume relative to the ambient velocity p is the ambient air density and y is a factor which varies from 0 to 1 and has to be chosen by the user Small value
394. he following definition makes this happen Additionally vid 7 must be specified in the ELEMENT DISCRETE keyword for this spring DEFINE SD ORIENTATION 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 10 32 DEFINE LS DYNA Version 960 DEFINE 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 DEFINE VECTOR 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Define vector number 5 from 0 0 0 to 0 1 1 As an example this vector can be used to define the direction of the prescribed velocity of a node using the BOUNDARY PRESCRIBED MOTION NODE keyword DEFINE VECIOR vo eren Den Be ee Den en Gee es men 5 vid xt yt zt xh yh zh 3 0 0 0 0 0 0 0 0 1 0 1 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 10 33 DEFINE DEFINE 10 34 DEFINE LS DYNA Version 960 DEFORMABLE TO RIGID DEFORMABLE TO RIGID The cards in this section are defined in alphabetical order and are as follows DEFORMABLE TO RIGID DEFORMABLE TO RIGID AUTOMATIC DEFORMABLE TO RIGID INERTIA If one of these cards is defined then any deformable part defined in the model may be switched to rigid during the calculation Parts that are defined as rigid RIGID in the input are permanently rigid and canno
395. he same order that the integration points are defined The data at each integration point consists of the following five values for elastic plastic Hughes Liu beams the normal stress Orr the transverse shear stresses Ors and the effective plastic strain and the axial strain which is logarithmic For beams that are not elastic plastic the first history variable if any is output instead of the plastic strain For the beam elements of Belytschko and his co workers the transverse shear stress components are not used in the formulation No data is output for the Belytschko Schwer resultant beam If mass scaling 1s active the output of the time step size reveals little information about the calculation If global mass scaling is used for a constant time step the total element mass is output however if the mass is increased so that a minimum time step size is maintained the added mass is output Also see the control card CONTROL TIMESTEP LS DYNA Version 960 9 19 DATABASE DATABASE For the SSSTAT option the following card s apply Define as many cards as necessary Card Format Define one part set ID for each subsystem Use as many cards as necessary PSID1 PSID2 PSID3 PSID4 PSID5 PSID6 PSID7 PSID8 VARIABLE DESCRIPTION PSIDn Part set ID for subsystem n see SET PART 9 20 DATABASE LS DYNA Version 960 DATABASE DATABASE FORMAT Purpose Define the output format for binary files Card Format 1 2
396. he velocities are initialized in the order the VELOCITY GENERATION input is defined Later input via the INITIAL VELOCITY GENERATION keyword overwrite the velocities previously set 3 For rigid bodies initial velocities given in PART_INERTIA will overwrite generated initial velocities 4 Nodes which belong to rigid bodies must have motion consistent with the translational and rotational velocity of the rigid body During initialization the rigid body translational and rotational rigid body momentum s are computed based on the prescribed nodal velocities From this rigid body motion the velocities of the nodal points are computed and reset to the new values These new values may or may not be the same as the values prescribed for the node 16 24 INITIAL LS DYNA Version 960 INITIAL INITIAL_VOID_OPTION Available options are PART SET Purpose Define initial voided part set ID s or part numbers Void materials cannot be created during the calculation Fluid elements which are evacuated e g by a projectile moving through the fluid during the calculation are approximated as fluid elements with very low densities The constitutive properties of fluid materials used as voids must be identical to those of the materials which will fill the voided elements during the calculation Mixing of two fluids with different properties is not permitted with this option Card Format Card 1 1 2 3 4 5 6 7 8
397. head of vector YH Y coordinate of head of vector ZH Z coordinate of head of vector Remark 1 The coordinates should differ by a certain margin to avoid numerical inaccuracies LS DYNA Version 960 10 29 DEFINE DEFINE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 DEFINE BOX 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Define box number eight which encloses a volume defined by two corner points 20 0 39 0 0 0 and 20 0 39 0 51 0 As an example this 5 box can be used as an input for the INITIAL VELOCITY keyword in which 6 all nodes within this box are given a specific initial velocity DEFINE BOX 5 DD BZ Din REN 5 boxid xmm xmx ym ymx zm 2 8 20 0 20 0 39 0 39 0 0 0 51 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 955 DEFINE COORDINATE NODES 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Define local coordinate system number 5 using three nodes 10 11 and 20 Nodes 10 and 11 define the local x direction Nodes 10 and 20 define the local x y plane For example this coordinate system or any coordinate system defined using a DEFINE COORDINATE option keyword can be used to define the local coordinate system of a
398. her constraint set that constrain the same degrees of freedom a tied interface or a rigid body i e nodes cannot be subjected to multiple independent and possibly conflicting constraints Also care must be taken to ensure that single point constraints applied to nodes in a constraint set do not conflict with the constraint sets constrained degrees of freedom 2 When the failure time is reached the rivet becomes inactive and the constrained nodes may move freely 5 64 CONSTRAINED LS DYNA Version 960 CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONSTRAINED RIVET 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Connect node 382 to node 88471 with massless rivet CONSTRAINED RIVET Se De Le De Da an Dan din Ebner Tees Dane 5 ni n2 tf 382 88471 0 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 5 65 CONSTRAINED CONSTRAINED CONSTRAINED SHELL TO SOLID Purpose Define a tie between a shell edge and solid elements Nodal rigid bodies can perform the same function and may also be used Card Format VARIABLE DESCRIPTION NID Shell node ID NSID Solid nodal set ID see SET NODE OPTION Remarks The shell brick interface an extension of the tied surface capability ties regions of hexahedron elements to regions of shell elements A
399. here it has been observed that sometimes rather large nonphysical thicknesses are specified to achieve high stiffness values Since the global searching algorithm includes the effects of shell thicknesses it is possible to slow the searches down considerably by using such nonphysical thickness dimensions 3 initial penetration check option is always performed in v 950 irregardless of the value of ISLCHK If you do not want to remove initial penetrations then set the contact birth time see so that the contact is not active at time 0 4 Automatic reorientation requires offsets between the master and slave surface segments The reorientation is based on segment connectivity and once all segments are oriented consistently based on connectivity a check is made to see if the master and slave surfaces face each other based on the right hand rule If not all segments in a given surface are reoriented This procedure works well for non disjoint surfaces If the surfaces are disjoint the AUTOMATIC contact options which do not require orientation are recommended In the FORMING contact options automatic reorientation works for disjoint surfaces LS DYNA Version 960 7 33 CONTROL CONTROL CONTROL_COUPLING Purpose Change defaults for MADYMO3D CAL3D coupling see Appendix F Card Format Card 1 1 2 3 4 5 6 7 8 UNLENG UNTIME UNFORC TIMIDL FLIPX FLIPY FLIPZ SUBCYL VARIABLE DESCRIPTION UNLENG Unit conve
400. hich belong to rigid parts are not in general checked for contact with only one exception The RIGIDWALL PLANAR option may be used with nodal points of rigid bodies if the planar wall defined by this option is fixed in space and the RWPNAL parameter is set to a positive nonzero value on the control card CONTROL CONTACT When the rigid wall defined in this section moves with a prescribed motion the equations of rigid body mechanics are not involved For a general rigid body treatment with arbitrary surfaces and motion refer to the CONTACT ENTITY definition The CONTACT ENTITY option is for treating contact between rigid and deformable surfaces only LS DYNA Version 960 22 1 RIGIDWALL RIGIDWALL RIGIDWALL GEOMETRIC OPTION OPTION Available forms include one is mandatory RIGIDWALL GEOMETRIC FLAT RIGIDWALL GEOMETRIC PRISM RIGIDWALL GEOMETRIC CYLINDER RIGIDWALL GEOMETRIC SPHERE If prescribed motion is desired an additional option is available MOTION One of the shape types FLAT PRISM CYLINDER SPHERE must be specified followed by the optional definition of MOTION both on the same line with RIGIDWALL GEOMETRIC Purpose Define a rigid wall with an analytically described form Four forms are possible A prescribed motion is optional For general rigid bodies with arbitrary surfaces and motion refer to the CONTACT ENTITY definition This option is for treating contact between rigid and deformable surfaces only Card Form
401. hould be used here LS DYNA Version 960 21 11 PART PART VARIABLE DESCRIPTION SIGREC Stress recovery flag If active attachment nodes should not be used 0 no stress recovery EQ 1 recover stresses FILENAME The path and name of a file which containes the modes for this rigid body MODEn Keep normal mode MODEn MSTART First mode for damping 1 MSTART lt MSTOP Last mode for damping MSTOP 1 lt MSTOP NMFB All modes between MSTART and MSTOP inclusive are subject to the same modal damping coefficient DAMPF DAMPF Modal damping coefficient 6 Remarks l The format of the file which contains the normal modes follows the file formats of NASTRAN output for modal information The mode set typically combines both normal modes and attachment modes The eigenvalues for the attachment modes are computed from the stiffness and mass matrices The part ID specified must be either a single rigid body or a master rigid body see CONSTRAINED RIGID BODIES which can be made up of many rigid parts The modal damping is defined by the modal damping coefficient where a value of 1 0 equals critical damping For a one degree of freedom model system the relationship between the damping and the damping coefficient is c 260 m where c is the damping m is the mass and c is the natural frequency k m There are two formulation options The first is a formulation that contains all the
402. i Figure 17 2 Definition of integration points for user defined integration rule Remarks The input for standard beam section types is defined below In Figures 17 3a and 17 3b the dimensions are shown on the left and the location of the integration points are shown on the right If a quantity is not defined in the sketch then it should be set to zero in the input The input quantities include LS DYNA Version 960 17 3 INTEGRATION INTEGRATION w flange width te flange thickness d depth web thickness Sref location of reference surface normal to s Hughes Liu beam only tef location of reference surface normal to t Hughes Liu beam only Type 1 W section Type 2 C section n ty S d s Type 3 Angle section Type 4 T section Figure 17 3a Standard beam cross sections 17 4 INTEGRATION LS DYNA Version 960 INTEGRATION Type 5 Rectangular tubin Type 7 Trapezoidal section FEN FERN d Ev Figure 17 3b Standard beam cross sections W LS DYNA Version 960 17 5 INTEGRATION INTEGRATION INTEGRATION_SHELL Purpose Define user defined through the thickness integration rules for the shell element This option applies to three dimensional shell elements with three or four nodes ELEMENT_SHELL types 1 11 and 16 and to the eight nodel thick shell ELEMENT_TSHELL Card Format Card 1 1 2 3 4 5 6 7 8 Define NIP cards below if ESOP 0
403. ian calculations See also ALE MULTI MATERIAL GROUP ALE SMOOTHING INITIAL_ VOID OPTION and SECTION SOLID ALE Card Format Card 1 1 2 3 4 5 6 7 8 A ERENER Card 2 1 2 3 4 5 6 7 8 I VARIABLE DESCRIPTION DCT Default continuum treatment EQ 1 Lagrangian default EQ 2 Eulerian EQ 3 Arbitrary Lagrangian Eulerian EQ 4 Eulerian Ambient NADV Number of cycles between advections METH Advection method EQ 1 donor cell HIS first order accuracte EQ 2 Van Leer HIS second order 7 10 CONTROL LS DYNA Version 960 VARIABLE AFAC BFAC CFAC DFAC EFAC START END AAFAC VFACT VLIMIT EBC LS DYNA Version 960 CONTROL DESCRIPTION ALE smoothing weight factor Simple average EQ 1 turn smoothing off ALE smoothing weight factor Volume weighting ALE smoothing weight factor Isoparametric ALE smoothing weight factor Equipotential ALE smoothing weight factor Equilibrium Start time for ALE smoothing End time for ALE smoothing ALE advection factor donor cell options default 1 0 Volume fraction limit for stresses in single material and void formulation All stresses are set to zero for elements with lower volume fraction than VFACT EQ 0 0 set to default 1 0E 06 Velocity limit The time step is scaled down if the velocitiy exceed this limit Automatic Euler boundary condition 0 off EQ 1 On with stick condition
404. icanly This must be done manually by reducing the time step scale factor on the CONTROL_TIMESTEP control card Since a good value of is not easily identified the coefficient COEF is defined such that a value of 10 roughly corresponds to 10 damping in the high frequency domain LS DYNA Version 960 8 5 DAMPING DAMPING Energy dissipated by Rayleigh damping is computed if and only if the flag RYLEN on the control card CONTROL ENERGY is set to 2 This energy is acummulated as element internal energy and is included in the energy balance In the GLSTAT file this energy will be lumped in with the internal energy 8 6 DAMPING LS DYNA Version 960 DAMPING DAMPING RELATIVE Purpose Apply damping relative to the motion of a rigid body Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION CDAMP Fraction of critical damping FREQ Frequency at which CDAMP is to apply cycles per unit time e g Hz if time unit is seconds PIDRB Part ID of rigid body see PART Motion relative to this rigid body will be damped PSID Part set ID The requested damping is applied only to the parts in the set Remarks 1 This feature provides damping of vibrations for objects that are moving through space The vibrations are damped but not the rigid body motion This is achieved by calculating the velocity of each node relative to that of a rigid body and applying a damping force proportional to that velocity The forces are reacted o
405. ich a detonation wave passes is given as t P t where and the time constant below are functions of the type and weight W of the explosive charge and the distance Q from the charge 131 Po 0 0 E K wm Q where o y and are constants for the explosive being used Element covering surface must have outward facing normal vectors Figure 19 4 The shell elements interacting with the fluid must be numbered such that their outward normal vector points into the fluid media 19 32 LOAD LS DYNA Version 960 LOAD LOAD_SUPERPLASTIC_FORMING Purpose Perform superplastic forming SPF analyses This option can be applied to both solid and shell elements The pressure loading controlled by the load curve ID given below is scaled to maintain a constant maximum strain rate This option must be used with material model 64 MAT RATE SENSITIVE POWERLAW PLASTICITY for strain rate sensitive powerlaw plasticity For the output of data see DATA BASE_SUPERPLASTIC_FORMING Mass scaling is recommended in SPF applications Card Format 1 2 3 4 5 6 7 8 I LI 1 1 2 3 4 5 6 7 8 LS DYNA Version 960 19 33 LOAD LOAD VARIABLE DESCRIPTION LCP1 Load curve number for Phase I pressure loading see DEFINE CURVE CSP1 Contact surface number to determine completion of Phase 1 Percent of nodes in contact to terminate Phas
406. icit mode selects time step size CONTROL_IMPLICIT_SOLVER Selects parameters for solving system of linear equations K x f CONTROL_IMPLICIT_SOLUTION Selects linear or nonlinear solution method convergence tolerances CONTROL_IMPLICIT_AUTO Activates automatic time step control CONTROL_IMPLICIT_DYNAMICS Activates and controls dynamic implicit solution using Newmark method CONTROL IMPLICIT EIGENVALUE Activates and controls eigenvalue analysis CONTROL IMPLICIT STABILIZATION Activates and controls artificial stabilization for multi step springback 7 2 CONTROL LS DYNA Version 960 CONTROL CONTROL ACCURACY Purpose Define control parameters that can improve the accuracy of the calculation Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION OSU Global flag for objective stress updates See Remark below Generally for explicit calculations only those parts undergoing large rotations such as rolling tires need this options Objective stress updates can be activated for a subset of part IDs by defining the part set in columns 21 30 EQ 0 Off default EQ 1 On INN Invarient node numbering for shell element See Remark 2 below EQ 1 Off default EQ 2 On PIDOSU Part set ID for objective stress updates If this part set ID is given only those part IDs listed will use the objective stress update therefore OSU is ignored Remarks 1 Objective stress updates are occasionally neces
407. ided by yield 3 origin space time see DEFINE_ CURVE and remark below CFL Conversion factor kft to LS DYNA length units CFT Conversion factor milliseconds to LS DYNA time units CFP Conversion factor psi to LS DYNA pressure units Remark If these curves are defined a variable yield is assumed Both load curves must be specified for the variable yield option If this option is used the shock time of arrival is found from the time of arrival curve The yield used in the Brode formulas is computed by taking the value from the yield scaling curve at the current time 1 13 and multiplying that value by yield LS DYNA Version 960 19 13 LOAD LOAD LOAD_DENSITY_DEPTH Purpose Define density versus depth for gravity loading This option has been occasionally used for analyzing underground and submerged structures where the gravitational preload is important The purpose of this option is to initialize the hydrostatic pressure field at the integration points in the element This card should be only defined once in the input deck Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PSID Part set ID see SET_PART If a PSID of zero is defined then all parts are initialized GC Gravitational acceleration value DIR Direction of loading EQ 1 global x EQ 2 global y EQ 3 global z LCID Load curve ID defining density versus depth see D
408. in the same format as the WANG_NEFSKE_JETTING options 1 34 AIRBAG LS DYNA Version 960 AIRBAG Additional cards required for HYBRID_CHEMKIN model The HYBRID_CHEMKIN model includes 3 control cards For each gas species an additional set of cards must follow consisting of a control card and several thermodynamic property data cards Card 1 1 2 3 4 5 6 7 8 LCIDM LCIDT NGAS DATA ATMT ATMP w foe fe fe BGE fe wl Card 2 1 2 3 4 5 6 7 8 Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCIDM Load curve specifying input mass flow rate versus time GT 0 piece wise linear interpolation LT 0 cubic spline interpolation LCIDT Load curve specifying input gas temperature versus time GT 0 piece wise linear interpolation LT 0 cubic spline interpolation LS DYNA Version 960 1 35 AIRBAG AIRBAG VARIABLE DESCRIPTION NGAS Number of gas inputs to be defined below Including initial air DATA Thermodynamic database EQ 1 NIST database 3 additional property cards are required below EQ 2 CHEMKIN database no additional property cards are required EQ 3 Polynomial data 1 additional property card is required below NGAS Number of gas inputs to be defined below Including initial air ATMT Atmospheric temperature ATMP Atmospheric pressure RG Universal gas constant HCONV Convection heat transfer coefficient C23 Vent orifice coefficient A23 Vent orifice area For each gas species include a set of card
409. ined by the following two nodes LS DYNA Version 960 10 21 DEFINE DEFINE VARIABLE XT YT ZT NID1 NID2 Remarks DESCRIPTION x value of orientation vector Define if IOP 0 1 y value of orientation vector Define if IOP 0 1 z value of orientation vector Define if IOP 0 1 Node 1 ID Define if IOP 2 3 Node 2 ID Define if IOP 2 3 1 orientation vectors defined by options 0 and 1 are fixed in space for the duration of the simulation Options 2 and 3 allow the orientation vector to change with the motion of the nodes Generally the nodes should be members of rigid bodies but this is not mandatory When using nodes of deformable parts to define the orientation vector care must be taken to ensure that these nodes will not move past each other If this happens the direction of the orientation vector will immediately change with the result that initiate severe instabilities can develop 10 22 DEFINE LS DYNA Version 960 DEFINE DEFINE TABLE Purpose Define a table This input section is somewhat unique in that another keyword DEFINE CURVE is used as part of the input in this section A table consists of a DEFINE TABLE card followed by n lines of input Each of the n additional lines define a numerical value in ascending order corresponding to a DEFINE CURVE input which follows the DEFINE TABLE keyword and the related input For example to define strain rate dependency where it is desi
410. ing and orientation of the local coordinate system is important for determining spotweld failure 5 8 CONSTRAINED LS DYNA Version 960 CONSTRAINED Additional Card required for the FILLET option Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TFAIL Failure time for constraint set default 1 E 20 EPSF Effective plastic strain at failure defines ductile failure SIGY Of stress at failure for brittle failure BETA B failure parameter for brittle failure L L length of fillet butt weld see Figure 5 2 and 5 3 W w width of flange see Figure 5 2 A a width of fillet weld see Figure 5 2 ALPHA a weld angle see Figure 5 2 in degrees Remarks Ductile fillet weld failure due to plastic straining is treated identically to spotweld failure Brittle failure of the fillet welds occurs when 3 72 eu 20r where On normal stress shear stress in direction of weld local y Tt shear stress normal to weld local x Of failure stress B failure parameter Component On is nonzero for tensile values only When the failure time ty is reached the nodal rigid body becomes inactive and the constrained nodes may move freely In Figure 5 2 the ordering of the nodes is shown for the 2 node and 3 node fillet welds This order is with respect to the local coordinate system where the local z axis determines the tensile direction The nodes in the fillet weld may coincide The failure of the 3 node fille
411. ing symmetry plane This option applies to continuum domains modeled with solid elements Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Nodal set ID see SET NODE VX x component of vector defining normal or vector VY y component of vector defining normal or vector VZ z component of vector defining normal or vector COPT Option EQ 0 node moves on normal plane EQ 1 node moves only in vector direction Remarks Any node may be constrained to move on an arbitrarily oriented plane or line depending on the choice of COPT Each boundary condition card defines a vector originating at 0 0 0 and terminating at the coordinates defined above Since an arbitrary magnitude is assumed for this vector the specified coordinates are non unique and define only a direction Use of BOUNDARY SPC is preferred over BOUNDARY SLIDING PLANE as the boundary conditions imposed via the latter have been seen to break down somewhat in lengthy simulations owing to numerical roundoff LS DYNA Version 960 3 43 BOUNDARY BOUNDARY BOUNDARY SPC OPTION Available options include NODE SET Purpose Define nodal single point constraints Do not use this option in r adaptive problems since the nodal point ID s change during the adaptive step If possible use CONSTRAINED GLOBAL instead Card Format 1 2 3 4 5 6 7 8 NID NSID DOFX DOFY DOFZ DOFRX DOFRY DOFRZ VARIABLE DESCRIPTION NID NSID Node ID or nodal set ID see SET NODE CID
412. ingback This section is terminated by an indicating the next input section Card Format VARIABLE DESCRIPTION NID Node ID 29 26 RESTART LS DYNA Version 960 VARIABLE TC RC LS DYNA Version 960 RESTART DESCRIPTION Tranlational constraint EQ 0 EQ 1 EQ 2 EQ 3 EQ 4 5 6 7 no constraints constrained x displacement constrained y displacement constrained z displacement constrained x and y displacements constrained y and z displacements constrained z and x displacements constrained x y and z displacements Rotational constraint EQ 0 EQ 1 2 3 EQ 4 EQ 5 EQ 6 EQ 7 no constraints constrained x rotation constrained y rotation constrained z rotation constrained x and y rotations constrained y and z rotations constrained z and x rotations constrained x y and z rotations 29 27 RESTART RESTART RIGID DEFORMABLE OPTION The OPTIONS available are CONTROL D2R Deformable to rigid part switch R2D Rigid to deformable part switch Purpose Define parts to be switched from rigid to deformable and deformable to rigid in a restart It is only possible to switch parts on a restart 1f part switching was activated in the time zero analysis See DEFORMABLE TO RIGID for details of part switching 29 28 RESTART LS DYNA Version 960 RESTART For the CONTROL option define the following card Card Format 1
413. input is read so that gaps in the element numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not element ID s OPTION Option for GENERAL See table below Specified entity Each card must have the option specified See table below 24 6 SET LS DYNA Version 960 SET OPTION ENTITY define up to 7 FUNCTION All discrete elements will be included in the set el e2 e3 e4 e5 e7 Elements e1 e2 e3 will be included DELEM el e2 e3 e4 e5 e6 e7 Elements el e2 e3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Elements of parts p1 p2 p3 will be included DPART pl p2 p3 p4 p5 p6 p7 Elements of parts p1 p2 p3 previously added will be excluded b1 b2 b3 b4 b5 b6 b7 Elements inside boxes bl b2 will be included DBOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes b1 b2 previously added will be excluded LS DYNA Version 960 24 7 SET SET SET NODE OPTION Available options include LIST COLUMN LIST GENERATE GENERAL The option LIST GENERATE will generate a block of node ID s between a starting nodal ID number and an ending nodal ID number An arbitrary number of blocks can be specified to define the set Purpose Define a nodal set with some identical or unique attributes Card Format Cards 2 3 4 OPTION LIST The next card terminates the input 1 2 3 4 5 6 7 8 NIDI NID
414. integration EQ 4 4x4 integration EQ 5 5x5 integration This option allows a check of the penetration of the rigid body into the deformable slaved material Then virtual nodes at the location of the integration points are checked The optional load curves that are defined for damping versus relative normal velocity and for force versus normal penetration should be defined in the positive quadrant The sign for the damping force depends on the direction of the relative velocity and the treatment is symmetric if the damping curve is in the positive quadrant If the damping force is defined in the negative and positive quadrants the sign of the relative velocity is used in the table look up 6 39 CONTACT CONTACT Card 2 Format Card 2 1 2 3 4 5 6 7 8 Variable Type Default VARIABLE DESCRIPTION BT Birth time DT Death time SO Flag to use penalty stiffness as in surface to surface contact 0 contact entity stiffness formulation EQ 1 surface to surface contact method EQ n Inl is the load curve ID giving the force versus the normal penetration GO Flag for mesh generation of the contact entity for entity types 1 5 and 10 11 This is used for visualization in post processing only 0 mesh is not generated EQ 1 mesh is generated 6 40 CONTACT LS DYNA Version 960 CONTACT Cards 3 and 4 Format Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XC x center xc see remarks below
415. ion 960 1 17 AIRBAG AIRBAG where p is the pressure in the control volume The mass flow into the control volume is governed by the equation 2 ue o O y 1 m CoAo 4 2P1P where Co A and p are the inflator orifice coefficient area and gas density respectively If OPT is defined then for OPT set to 1 or 2 the mass flow rate out of the bag m is given out by nairmats Moy FAC p Area aoo n l where p is the density of airbag gas nairmats is the number of fabrics used in the airbag and Areag is the current unblocked area of fabric number n If OPT set to 3 or 4 then d FAC p re 2 p n 1 and for OPT set to 5 or 6 nairmats Y FLC 0 Are P Deu 1 Multiple airbags may share same part ID since the area summation is over airbag segments whose corresponding part ID s are known Currently we assume that no more than ten materials are used per bag for purposes of the output This constraint can be eliminated if necessary The total mass flow out will include the portion due to venting i e constants C23 and A23 or their load curves above If CV 0 then the constant pressure specific heat is given by a bT C MW and the constant volume specific heat is then found from 1 18 AIRBAG LS DYNA Version 960 AIRBAG Further additional 2 cards are required for JETTING models The following additi
416. ion 960 19 39 LOAD LOAD LOAD_THERMAL_VARIABLE Purpose Define nodal sets giving the temperature that is variable in the duration of the calculation The reference temperature state is assumed to be a null state with this option A nodal temperature state read in above and varied according to the load curve dynamically loads the structure Thus the defined temperatures are relative temperatures to an initial reference temperature Card Format Card 1 1 2 3 4 5 6 7 8 1 1 HK 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Nodal set ID containing nodes see SET NODE OPTION EQ 0 all nodes are included NSIDEX Nodal set ID containing nodes that are exempted optional see SET_ NODE OPTION BOXID All nodes in box which belong to NSID are initialized Others are excluded TS Scaled temperature 19 40 LOAD LS DYNA Version 960 VARIABLE TB LCID TSE TBE LCIDE Remark LOAD DESCRIPTION Base temperature Load curve ID that multiplies the scaled temperature see DEFINE_ CURVE Scaled temperature of the exempted nodes optional Base temperature of the exempted nodes optional Load curve ID that multiplies the scaled temperature of the exempted nodes optional see DEFINE CURVE l temperature is defined as T Tbase Tscale f t where f t is the current value of the load curve Tscale is the sca
417. ion force to a maximum A limiting force is computed VC A Acont being cont the area of the segment contacted by the node in contact The suggested o 48 value for VC is to use the yield stress in shear VC where is the yield stress of the contacted material Load curve ID defining x direction motion If zero there is no motion in the x coordinate system Load curve ID defining y direction motion If zero there is no motion in the y coordinate system Load curve ID defining z direction motion If zero there is no motion in the z coordinate system Load curve ID defining the static coefficient of friction as a function of interface pressure This option applies to shell segments only Load curve ID defining the dynamic coefficient of friction as a function of interface pressure This option applies to shell segments only Scale factor on default slave penalty stiffness see also CONTROL CONTACT 6 53 CONTACT CONTACT VARIABLE DESCRIPTION STTHK Optional thickness for slave surface overrides true thickness This option applies to contact with shell solid and beam elements True thickness is the element thickness of the shell elements Thickness offsets are not used for solid element unless this option is specified SFTHK Scale factor for slave surface thickness scales true thickness This option applies only to contact with shell elements True thickness is the element thickness of
418. ion is reduced below ECTOL this condition is satisfied Smaller numbers lead to more strict determination of equilibrium and on the negative side result in more iterations and higher costs A line search is sometimes performed to this tolerance to guard against divergence The search is done in the event that the system is stiffening which can often lead to a failure to converge during the equilibrium iterations When computing the displacement ratio the norm of the incremental displacement vector is divided by the norm of total displacement This total displacement may be either the total over the current step or the total over the entire simulation The latter tends to be more lax and can be poor at the end of simulations where large motions develop For these problems an effective combination is DNORM 1 and DCTOL 0 01 or larger By default a new stiffness matrix is formed whenever divergence growing out of balance force is detected This flag can be used to supress this stiffness reformation By default a new stiffness matrix is formed at the start of every time step Supressing this stiffness reformation can decrease the cost of simulations which have many tiny steps that are mostly linear This flag controls printing of displacement and energy convergence measures during the nonlinear equilibrium search If convergence difficulty occurs this information is helpful in determining the problem See also the section on i
419. ion point 2D solid element type Defined for ELFORM 13 14 and 15 EQ 1 Lagrangian EQ 2 Eulerian single material with voids EQ 3 ALE Shell thickness at node unless the thickness is defined on the ELEMENT SHELL OPTION card Shell thickness at node 2 see comment for T1 above Shell thickness at node n3 see comment for T1 above Shell thickness at node n4 see comment for T1 above Location of reference surface Hughes Liu shell only EQ 1 0 top surface EQ 0 0 mid surface default EQ 1 0 bottom surface Non structural mass per unit area This is additional mass which comes from materials such as carpeting This mass is not directly included in the time step calculation B1 material angle at first integration point B material angle at second integration point material angle at third integration point Bg material angle at eigth integration point material angle at nipth integration point 23 15 SECTION SECTION VARIABLE DESCRIPTION AFAC Smoothing weight factor Simple average EQ 1 turn smoothing off BFAC Smoothing weight factor Volume weighting CFAC Smoothing weight factor Isoparametric DFAC Smoothing weight factor Equipotential EFAC Smoothing weight factor Equilibrium START Start time for smoothing END End time for smoothing AAFAC ALE advection factor GAUSS INTEGRATION RULE 5773503 8611363 5773503 7745967 3399810 9061798 7745967 3
420. iplier for weld energy input rate energy time e g Watt forward distribution function reward distribution function Note F f F 2 0 weld beam direction vector in global coordinates N2ID 1 only This boundary condition allows simulation of a moving weld heat source following the work of Goldak J Goldak A New Finite Element Model for Welding Heat Sources Metallurgical Transactions B Volume 15B June 1984 pp 299 305 Heat is generated in a ellipsoidal region centered at the weld source and decaying exponentially with distance according to LS DYNA Version 960 3 49 BOUNDARY BOUNDARY ax 3y 342 E 6N3FQ _ Fee 4 z4zabc where 4 weld source power density x y z coordinates of point p in weld material Fr if point p is in front of beam R if point p is behind beam Cr if point p is in front of beam c if point p is behind beam A local coordinate system is constructed which is centered at the heat source The relative velocity vector of the heat source defines the forward direction so material points that are approaching the heat source are in front of the beam The beam aiming direction is used to compute the weld pool depth The weld pool width is measured normal to the relative velocity aiming direction plane 3 50 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY USA SURFACE Purpose Define a surface for coupling with the USA boundary element code DeRuntz 1993 The out
421. is active then nodes whose penetration then exceeds the product of XPENE and the element thickness are set free see CONTROL_OPTION_ EQ 0 default is set to 4 0 Flag for using actual shell thickness in single surface contact logic types 4 13 15 and 26 See remarks 1 and 2 below EQ 0 Actual shell thickness is not used in the contacts default EQ 1 Actual shell thickness is used in the contacts sometimes recommended for metal forming calculations Time step size override for eroding contact EQ 0 contact time size may control Dt EQ 1 contact is not considered in Dt determination Bypass projection of slave nodes to master surface in types CONTACT_ TIED_NODES_TO_SURFACE CONTACT_TIED_SHELL_EDGE_TO_ SURFACE and CONTACT TIED SURFACE TO SURFACE tied interface options EQ 0 eliminate gaps by projection nodes EQ 1 bypass projection Gaps create rotational constraints which can substantially affect results Default static coefficient of friction see PART CONTACT Default dynamic coefficient of friction see PART CONTACT Default exponential decay coefficient see PART CONTACT Default viscous friction coefficient see PART CONTACT Default contact thickness see PART CONTACT Default thickness scale factor see PART CONTACT Default local penalty scale factor see PART CONTACT Ignore initial penetrations in the CONTACT AUTOMATIC options This option can also be specified for each interface on the third optional c
422. is now possible Generalized set definitions 1 SET_SHELL_GENERAL etc provide much flexibility in the set definitions The command sw4 will write a state into the dynamic relaxation file D3DRLF during the dynamic relaxation phase if the D3DRLF file is requested in the input Added mass by PART ID is written into the MATSUM file when mass scaling is used to maintain the time step size SMP version only Upon termination due to a large mass increase during a mass scaled calculation a print summary of 20 nodes with the maximum added mass is printed Eigenvalue analysis of models containing rigid bodies is now available using BCSLIB EXT solvers from Boeing SMP version only Second order stress updates can be activated by part ID instead of globally on the CONTROL_ACCURACY input Interface frictional energy is optionally computed for heat generation and is output into the interface force file SMP version only The interface force binary database now includes the distance from the contact surface for the FORMING contact options This distance is given after the nodes are detected as possible contact candidates SMP version only Type 14 acoustic brick element is implemented This element is a fully integrated version of type 8 the acoustic element SMP version only A flooded surface option for acoustic applications is available SMP version only Attachment nodes can be defined for rigid bodies This option is useful for NVH
423. is useful for simple modifications EQ 0 0 default set to 1 0 OFFA Offset for abcissa values see explanation below OFFO Offset for ordinate values function see explanation below DATTYP Data type Usually 0 set to 1 only for general xy data This affects how offsets are applied General xy data curves refer to curves whose abcissa values do not increase monotonically Generally DATTYP 0 for time dependent curves force versus displacement curves and stress strain curves Al A2 Abcissa values Only pairs have to be defined see remarks below Ol O2 Ordinate function values Only pairs have to be defined see remarks below Remarks 1 Warning In the definition of Load Curves used in the constitutive models reasonable spacing of the points should always be observed i e never set a single point off to a value approaching infinity LS DYNA uses internally discretized curves to improve efficiency in the constitutive models Also since the constitutive models extrapolate the curves it is important to ensure that extrapolation does not lead to physically meaningless values such as a negative flow stress The load curve values are scaled after the offsets are applied i e Abcissa value SFA Defined value OFFA Ordinate value SFO Defined value OFFO Positive offsets for the load curves DATTYP 0 are intended for time versus function curves since two additional points are generated automatically at time
424. isena ni asus den POUR PESE ne Eee us ha 64 MAT ORIENTED CRACK nen er ee We tases leere 72 MAT_POWER LAW PLASTICITY zusehen 74 MAT STRAIN RATE DEPENDENT 5 2220201 76 MAT RIGID tet te ta ena ta Eoi ir 79 MAT ORTHOTROPIC 83 MAT COMPOSITE DAMAQGE a tren E eel RM a Reate 87 MAT TEMPERATURE DEPENDENT ORTHOTROPIC eee 91 MAT PIECEWISE LINEAR PLASTICITY 96 MAT GEOEOGICCCAP ERRBBRREEBHEBR tte e 100 HONEY COMB ei tide peo re rese De E edebat dee dte 106 MAT MOONEY RIVIJN RUBBER dessen ed e OT epe te ye neun 113 MAT RESUETANT PLASTICITY nee 820282 ee ai nee 116 MAT FORCE LIMITED ee 117 MAT SHAPE MEMORY 22 32 20 iii in 123 MAT FRAZER NASH RUBBER 127 MAT LAMINATED GLASS u eben then ig be kde sense 130 MAT BARLAT ANISOTROPIC PLASTICITY eene 132 MAT BARLA T YIDO06 222 222 ee nee ab Didier 135 BABRIG zo a na ONU OE MEI 139 MAT PLASTIC GREEN NAGHDI 04 144 MAT3 PARAMETER BARLA To unser do ee eoe hood Hi eere o odo e EROR Qe Tee test 145 MAT TRANSVERSELY ANISOTROPIC ELASTIC 149 MAT BLATZ KO FOAM ei RR te ni 152 MAT
425. ith THICKNESS option for each element and the NOTHICKNESS option is not available for NIKE3D The file name for the NIKE3D option is nikin The adaptive constraint option is not available for this option 2 The NOTHICKNESS option is available for DYNA3D and NASTRAN in which case the shell element thickness is not an output The file name for LS DYNA is dynain and for NASTRAN is nastin The CONTROL ADAPTIVITY is available for LS DYNA 3 Trimming is available for the adaptive mesh but it requires some steps To trim an adaptive mesh use the following procedure 1 Generate the file dynain using the keyword INTERFACE SPRINGBACK DYNA3D 2 Prepare a new input deck including the file dynain 3 Add the keyword ELEMENT_TRIM to this new deck 4 Add the keyword DEFINE CURVE TRIM to this new deck 5 Run this new input deck with file name The adaptive constraints eliminated by remeshing and the trimming is performed 6 In case this new trimmed mesh is needed run a zero termination time job and output the file generated via the keyword INTERFACE SPRINGBACK DYNA3D Remarks for Seamless Springback Seamless springback avoids the use of LS NIKE3D for static springback analysis Instead LS DYNA automatically and seamlessly switches from explicit dynamic to implicit static mode at the end of a forming simulation and continues to run the static springback analysis Seamless spri
426. ith limited capabilities Built in least squares fit for rubber model constitutive constants Large hystersis in hyperelastic foam Bilhkw Dubois foam model Generalized rubber model s added in 1995 Belytschko Leviathan Shell Automatic switching between rigid and deformable bodies Accuracy on SMP machines to give identical answers on one two or more processors Local coordinate systems for cross section output can be specified Null material for shell elements Global body force loads now may be applied to a subset of materials User defined loading subroutine Improved interactive graphics New initial velocity options for specifying rotational velocities Geometry changes after dynamic relaxation can be considered for initial velocities Velocities may also be specified by using material or part ID s Improved speed of brick element hourglass force and energy calculations Pressure outflow boundary conditions have been added for the ALE options More user control for hourglass control constants for shell elements Full vectorization in constitutive models for foam models 57 and 63 Damage mechanics plasticity model material 81 General linear viscoelasticity with 6 term prony series Least squares fit for viscoelastic material constants Table definitions for strain rate effects in material type 24 Improved treatment of free flying nodes after element failure Automatic projection of nodes in CONTACT_TIED to elimi
427. ithm As currently implemented one surface of the interface is identified as a master surface and the other as a slave Each surface is defined by a set of three or four node quadrilateral segments called master and slave segments on which the nodes of the slave and master surfaces respectively must slide In general an input for the contact impact algorithm requires that a list of master and slave segments be defined For the single surface algorithm only the slave surface is defined and each node in the surface is checked each time step to ensure that it does not penetrate through the surface Internal logic Hallquist 1977 Hallquist et al 1985 identifies a master segment for each slave node and a slave segment for each master node and updates this information every time step as the slave and master nodes slide along their respective surfaces It must be noted that for general automatic definitions only parts materials or three dimensional boxes have to be given Then the possible contacting outer surfaces are identified by the internal logic in LS DYNA More than 20 types of interfaces can presently be defined including sliding only for fluid structure or gas structure interfaces tied sliding impact friction single surface contact discrete nodes impacting surface discrete nodes tied to surface shell edge tied to shell surface nodes spot welded to surface tiebreak interface one way treatment of sliding impact friction
428. itially in contact Until failure tangential motion is inhibited EQ 3 as 1 above but with failure after sticking EQ 4 tiebreak is active for nodes which are initially in contact but tangential motion with frictional sliding is permitted EQ 5 tiebreak is active for nodes which are initially in contact Damage is a nonlinear function of the crack width opening and is defined by a load curve which starts at unity for a crack width of zero and decays in some way to zero at a given value of the crack opening This interface can be used to represent deformable glue bonds EQ 6 This option is for use with solids and thick shells only Tiebreak is active for nodes which are initially in comtact Damage is a linear function of the maximum over time distanc C between points initially in contact When the distance is equal to CCRIT damage is fully developed and interface failure occurs After failure this contact olption behaves as a surface to surface contact Assuming no load reversals the energy released due to the failure of the interface is 6 12 CONTACT LS DYNA Version 960 VARIABLE NFLS SFLS CCRIT Remarks CONTACT DESCRIPTION approximately 0 5 S CCRIT wher S is equal to 4 max o 0 at initiation of damage This interface may be used for simulating crack propagation For the energy release to be correct the contact penalty MIN NFLF SFLS stiffness must be much larger than CCRIT Normal failure st
429. ities and displacements can be imposed on rigid bodies If the local option is active the motion is prescribed with respect to the local coordinate system for the rigid body See variable LCO for keyword MAT RIGID Translational nodal velocity and acceleration specifications for rigid body nodes are allowed and are applied as described at the end of this section For nodes on rigid bodies use the NODE option Do not use the NODE option in r adaptive problems since the node ID s may change during the adaptive step Card Format Card 1 1 2 3 4 5 6 7 8 I b EP Card is required if DOF 9 10 11 on the first card or VAD 4 If DOF lt 9 and VAD lt 4 skip this card Card 2 1 2 3 4 5 6 7 8 LS DYNA Version 960 3 31 BOUNDARY BOUNDARY VARIABLE DESCRIPTION NID NSID PID Node ID NID nodal set ID NSID SEE SET or part ID PID see PART for a rigid body DOF Applicable degrees of freedom EQ 1 x translational degree of freedom EQ 2 y translational degree of freedom EQ 3 z translational degree of freedom EQ 4 translational motion in direction given by the VID Movement on plane normal to the vector is permitted EQ 4 translational motion in direction given by the VID Movement on plane normal to the vector is not permitted This option does not apply to rigid bodies EQ 5 x rotational degree of freedom EQ 6 y rotational degree of freedom EQ 7 z rotational degree of freedom EQ 8 rotational
430. ives greater clarity to input decks LS DYNA Version 960 23 1 SECTION SECTION SECTION_BEAM Purpose Define cross sectional properties for beam truss discrete beam and cable elements Card Format Card 1 1 2 3 4 2 6 7 8 me HE RE tet et ete Define the appropriate card format depending on the value of ELFORM 1 9 above Card 2 Integrated spotweld TS1 TS2 TT2 NSLOC NTLOC 1 4 5 7 8 9 Resultant 2 3 A ISS ITT IRR SA Discrete 6 VOL INER CID CA OFFSET RRCON SRCON TRCON VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique ELFORM Element formulation options EQ 1 Hughes Liu with cross section integration default EQ 2 Belytschko Schwer resultant beam resultant EQ 3 truss resultant see remark 2 EQ 4 Belytschko Schwer full cross section integration EQ 5 Belytschko Schwer tubular beam with cross section integration EQ 6 discrete beam cable EQ 7 2D plane strain shell element xy plane EQ 8 2D axisymmetric volume weighted shell element xy plane EQ 9 spotweld beam see MAT SPOTWELD 23 2 SECTION LS DYNA Version 960 SECTION VARIABLE DESCRIPTION Note that the 2D and 3D element types must not be mixed and different types of 2D elements must not be used together For example the plane strain element type must not be used with the axisymmetric element type In 3D the different beam elements types i e 1 6 and 9 can
431. ks 1 coefficients of friction are defined in terms of the static dynamic and decay coefficients and the relative velocities in the local a and b directions as AyaVrelative a Ua Je dui dy Vos ive b Uy Lye 2 Orthotropic rigid walls can be used to model rolling objects on rigid walls where the frictional forces are substantially higher in a direction transverse to the rolling direction To use this option define a vector d to determine the local frictional directions via b nxd and that a bx n where n is the normal vector to the rigid wall If d is in the plane of the rigid wall then a is identical to d 22 16 RIGIDWALL LS DYNA Version 960 RIGIDWALL Optional Card C Required if FINITE is specified after the keyword See Figure 23 3 The m vector is computed as the vector cross product X The origin the tail of the normal vector is taken as the corner point of the finite size plane Optional 1 Card C 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XHEV x coordinate of head of edge vector I see Figure 22 3 YHEV y coordinate of head of edge vector 1 ZHEV z coordinate of head of edge vector 1 LENL Length of l edge LENM Length of m edge LS DYNA Version 960 22 17 RIGIDWALL RIGIDWALL Optional Card D Required if MOVING is specified after keyword Note The MOVING option is not compatible with the ORTHO option Optional 1 Card D 2 3 4 5 6 7 8 VARIABLE DESCRI
432. ks Remarks 1 through 9 pertain to 20 AUTOMATIC contact 1 For AUTOMATIC_SURFACE_TO_SURFACE AUTOMATIC_SINGLE_SURFACE contact and AUTOMATIC_NODE_TO_SURFACE contact penetration of 2D shell elements and external faces of 2D continuum elements is prevented by penalty forces Parts in the slave part set are checked for contact with parts in the master part set Self contact is checked for any part in both sets If the slave part set is omitted all parts are checked for contact If the master part set is omitted it is assumed to be identical to the slave part set For AUTOMATIC_SURFACE_IN_CONTINUUM contact penalty forces prevent the flow of slave element material the continuum through the master surfaces Flow of the continuum tangent to the surface is permitted Only 2D solid parts are permitted in the slave part set Both 2D 2D solid and 2D shell parts are permitted in the master part set Neither the slave part set ID nor the master part set ID may be omitted By default the true thickness of 2D shell elements is taken into account for AUTOMATIC_ SURFACE SURFACE and AUTOMATIC NODE TO SURFACE contact The user can override the true thickness by using SOS and SOM If the surface offset is reduced to a small value the automatic normal direction algorithm may fail so it is best to specify the normal direction using NDS or NDM Thickness of 2D shell elements is not considered for AUTOMATIC SURFACE IN CONTINUUM contact By default the
433. l energy balance this energy is included with the energy of the discrete elements i e the springs and dampers Card Format Card 1 is common to all joint stiffness types Cards 2 to 4 are unique for each stiffness type Card 1 Required for all joint stiffness types Card 1 1 2 3 4 5 VARIABLE DESCRIPTION JSID Joint stiffness ID PIDA Part ID for rigid body A see PART PIDB Part ID for rigid body B see PART CIDA Coordinate ID for rigid body A see DEFINE_COORDINATE_OPTION CIDB Coordinate ID for rigid body B If zero the coordinate ID for rigid body A is used see DEFINE COORDINATE OPTION 5 34 CONSTRAINED LS DYNA Version 960 CONSTRAINED Card 2 of 4 Required for GENERALIZED stiffness Card 2 1 2 3 4 5 6 LCIDPH LCIDT LCIDPS DLCIDPH DLCIDT DLCIDPS Be d Default none none none none none none VARIABLE DESCRIPTION LCIDPH Load curve ID for moment versus rotation in radians See Figure 5 15 If zero the applied moment is set to 0 0 See DEFINE_CURVE LCIDT Load curve ID for 0 moment versus rotation in radians If zero the applied moment is set to 0 0 See DEFINE_CURVE LCIDPS Load curve ID for y moment versus rotation in radians If zero the applied moment is set to 0 0 See DEFINE_CURVE DLCIDPH Load curve ID for d damping moment versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE_CURVE DLCIDT Lo
434. l load curve ID giving mass flow out versus gauge pressure in bag See DEFINE CURVE TEXT Ambient temperature Define if and only if CV 0 A First heat capacity coefficient of inflator gas e g Joules mole K Define if and only if CV 0 B Second heat capacity coefficient of inflator gas e g Joules mole K2 Define if and only if CV 0 MW Molecular weight of inflator gas e g Kg mole Define if and only if CV 0 GASC Universal gas constant of inflator gas e g 8 314 Joules mole K Define if and only if CV 0 Remarks The gamma law equation of state used to determine the pressure in the airbag p Y 1 pe where is the pressure p is the density e is the specific internal energy of the gas and y is the ratio of the specific heats yo v From conservation of mass the time rate of change of mass flowing into the bag is given as dM out dt dt dt The inflow mass flow rate is given by the load curve ID LCID Leakage the mass flow rate out of the bag can be modeled in two alternative ways One is to give an exit area with the corresponding shape factor then the load curve ID LOU must be set to zero The other is to define a mass flow out by a load curve then u and A have to both be set to zero If CV 0 then the constant pressure specific heat is given by a bT i MW and the constant volume specific heat is then found from R LS DYNA Version 960
435. lational velocity in global coordinate system VTY y rigid body initial translational velocity in global coordinate system VTZ z rigid body initial translational velocity in global coordinate system VRX x rigid body initial rotational velocity in global coordinate system VRY y rigid body initial rotational velocity in global coordinate system VRZ z rigid body initial rotational velocity in global coordinate system Optional card required for IRCS 1 Define two local vectors or a local coordinate system ID Card 5 1 2 3 4 5 6 7 8 mm fe Default none none none none none none none VARIABLE DESCRIPTION XL x coordinate of local x axis Origin lies at 0 0 0 y coordinate of local x axis ZL z coordinate of local x axis XLIP x coordinate of local in plane vector YLIP y coordinate of local in plane vector ZLIP z coordinate of local in plane vector CID Local coordinate system ID see DEFINE COORDINATE With this option leave fields 1 6 blank Remark The local coordinate system is set up in the following way After the local x axis is defined the local z axis is computed from the cross product of the local x axis vector with the given in plane vector Finally the local y axis is determined from the cross product of the local z axis with the local x axis The local coordinate system defined by CID has the advantage that the local system can be defined by nodes in the rigid body which makes repositioning of
436. le for time histories of selected data default D3THDT xtf binary plot file for time extra data default XTFILE tpf optional temperature file TOPAZ3D plotfile rrd running restart dump file defaultZRUNRSF sif stress initialization file user specified jif optional JOY interface file iff interface force file user specified isfl interface segment save file to be created user specified isf2 existing interface segment save file to be used user specified rlf binary plot file for dynamic relaxation defaultZD3DRFL efl echo file containing optional input echo with or without node element data root root file name for general print option scl scale factor for binary file sizes default 7 cpu cpu limit in seconds applies to total calculation not just cpu from a restart kill if LS DYNA encounters this file name it will terminate with a restart file default D3 KIL vda VDA IGES database for geometrical surfaces c3d CAL3D input file nwds Number of words to be allocated On engineering workstations a word is usually 32bits This number is ignored if memory is specified on the KEYWORD card at the beginning of the input deck ncpu Overrides NCPU and CONST defined in CONTROL PARALLEL A positive value sets CONST 2 and a negative values sets CONST 1 See CONTROL_PARALLEL for an explanation of these parameters npara Overrides PARA defined in CONTROL_PARALLEL time Overrides ENDTIM defined in CONTROL_TERM
437. le printing of linear equation solver memory cpu summary nlprint Enable Disable printing of nonlinear equilibrium iteration information iter Enable Disable output of binary plot database d3iter showing mesh after each equilibrium iteration Useful for debugging convergence problems conv Temporarily override nonlinear convergence tolerances stop Halt execution immediately closing open files On UNIX systems the sense switches can still be used if the job is running in the background or in batch mode To interrupt LS DYNA simply create a file call D3KIL containing the desired sense switch e g sw1 LS DYNA periodically looks for this file and if found the sense switch contained therein is invoked and the D3KIL file is deleted A null D3KIL file is equivalent to a swl When LS DYNA terminates all scratch files are destroyed the restart file plot files and high speed printer files remain on disk Of these only the restart file is needed to continue the interrupted analysis PRECISION The explicit time integration algorithms used in LS DYNA are in general much less sensitive to machine precision than other finite element solution methods Consequently double precision is not used The benefits of this are greatly improved utilization of memory and disk When problems have been found we have usually been able to overcome them by reorganizing the algorithm or by converting to double precision locally in the subroutine where the
438. le values as low as 2 will provide slightly reduced accuracy with a 5096 reduction in the time required to compute the matrix of influence coefficients 3 10 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY ELEMENT METHOD FLOW Purpose Turn on the boundary element method calculation specify the set of shells which define the surface of the bodies of interest and specify the onset flow The BOUNDARY ELEMENT METHOD FLOW card turns on the BEM calculation This card also identifies the shell elements which define the surfaces of the bodies of interest and the properties of the onset fluid flow The onset flow can be zero for bodies which move through a fluid which is initially at rest Define one card 1 2 3 4 5 6 7 8 me fete tet ete VARIABLE DESCRIPTION SSID Shell set ID for the set of shell elements which define the surface of the bodies of interest see SET_SHELL The nodes of these shells should be ordered so that the shell normals point into the fluid VX VY VZ x y and z components of the free stream fluid velocity RO Fluid density PSTATIC Fluid static pressure MACH Free stream Mach number LS DYNA Version 960 3 11 BOUNDARY BOUNDARY Remarks l t is recommended that the shell segments in the SSID set use the NULL material see MAT NULL This will provide for the display of fluid pressures in the post processor For triangular shells the 4th node number should be the same as the 3rd nod
439. led temperature and Tbase is the base temperature LS DYNA Version 960 19 41 LOAD LOAD LOAD_THERMAL_VARIABLE_NODE Purpose Define nodal temperature that are variable during the calculation The reference temper ature state is assumed to be a null state with this option A nodal temperature state read in and varied according to the load curve dynamically loads the structure Thus the defined temperatures are relative temperatures to an initial reference temperature Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Node ID TS Scaled temperature TB Base temperature LCID Load curve ID that multiplies the scaled temperature see DEFINE_ CURVE Remarks The temperature is defined as T Tbase Tscale f t where f t is the current value of the load curve Tscale is the scaled temperature Tbase is the base temperature 19 42 LOAD LS DYNA Version 960 NODE NODE Two keywords are defined in this section NODE NODE RIGID SURFACE LS DYNA Version 960 20 1 NODE NODE Purpose Define a node and its coordinates in the global coordinate system Also the boundary conditions in global directions can be specified Generally nodes are assigned to elements however exceptions are possible see remark 2 below Card Format 18 3E16 0 2F8 0 Card 1 1 2 3 4 3 6 7 8 9 10 TI VARIABLE DESCRIPTION NID Node numb
440. lid element ID see SET SOLID or ELEMENT_SOLID respectively LCID Load curve ID for volumetric heat generation rate 4 0 function versus time EQ 0 use multiplier value CMULT only LT 0 function versus temperature CMULT Curve multiplier for 4 Depending on the definition of LCID this value is either used for scaling or for constant heat generation 19 16 LOAD LS DYNA Version 960 LOAD LOAD_MASK Purpose Apply a distributed pressure load over a three dimensional shell part The pressure is applied to a subset of elements that are within a fixed global box and lie either outside or inside of a closed curve in space which is projected onto the surface Card Format 1 2 3 4 5 6 7 8 EPEC EE 1 2 3 4 gt 6 7 8 VARIABLE DESCRIPTION PID Part ID PID This part must consist of 3D shell elements To use this option with solid element the surface of the solid elements must be covered with null shells See MAT_NULL LCID Curve ID defining the pressure time history see DEFINE CURVE LS DYNA Version 960 19 17 LOAD LOAD VARIABLE VIDI OFF BOXID LCIDM VID2 INOUT ICYCLE Remarks DESCRIPTION Vector ID normal to the suface on which the applied pressure acts Positive pressure acts in a direction that is in the opposite direction This vector may be used if the surface on which the pressure acts is relatively flat If zero the pressure load d
441. locity change is used EQ 0 inactive Velocity change magnitude required to activate the inflator EQ 0 inactive Displacement increment in local x direction to activate the inflator The absolute value of the x displacement is used EQ 0 inactive Displacement increment in local y direction to activate the inflator The absolute value of the y displacement is used EQ 0 inactive Displacement increment in local z direction to activate the inflator The absolute value of the z displacement is used EQ 0 inactive Displacement magnitude required to activate the inflator EQ 0 inactive LS DYNA Version 960 AIRBAG Additional card required for SIMPLE_PRESSURE_VOLUME option 1 2 3 4 5 6 7 8 PE i ES m a mE VARIABLE DESCRIPTION CN Coefficient Define if the load curve ID LCID is unspecified LT 0 0 ICNI is the load curve ID which defines the coefficient as a function of time BETA Scale factor B Define if a load curve ID is not specified LCID Optional load curve ID defining pressure versus relative volume LCIDDR Optional load curve ID defining the coefficient CN as a function of time during the dynamic relaxation phase Remarks The relationship is the following CN Relative Volume Pressure D Current Volume Relative Volume Initial Volume The pressure is then a function of the ratio of current volume to the initial volume The constant CN is used to es
442. low high High temperature range NIST polynomial curve fit coefficients see below If DATA 3 include the following card for the polynomial curve fit card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION a Coefficient see below b Coefficient see below Coefficient see below d Coefficient see below e Coefficient see below Heat capacity curve fits 1 NIST c 2 t dr 5 CHEMKIN ge a t DT e cT dT eT 1 38 AIRBAG LS DYNA Version 960 AIRBAG R universal gas constant 8 314 Nm mole K M gas molecular weight Polynomial C a bT cT dT LS DYNA Version 960 1 39 AIRBAG AIRBAG AIRBAG INTERACTION Purpose To define two connected airbags which vent into each other Define one card for each airbag interaction definition 1 2 3 4 5 6 7 8 jin EN dui idi iat VARIABLE DESCRIPTION ABI First airbag ID as defined on AIRBAG card AB2 Second airbag ID as defined on AIRBAG card AREA Orifice area between connected bags LT 0 0 IAREAI is the load curve ID defining the orifice area as a function of absolute pressure EQ 0 0 AREA is taken as the surface area of the part ID defined below SF Shape factor LT 0 0 ISFI is the load curve ID defining vent orifice coefficient as a function of relative time PID Optional part ID of the partition between the interacting control volumes AREA is based on this part ID LCI
443. lt when IADVEC 40 Set the maximum number of iterations for the iterative equation solver EQ 0 MAXIT 100 default Set the interval to check the convergence criteria for the iterative equation solver EQ 0 ICHKIT 2 default Activate the output of diagnostic information from the equation solver EQ 0 Diagnostic information is off default EQ 1 Diagnostic information is on Activate the generation of a convergence history file from the equation solver The ASCII history files are velx his vely his and velz his EQ 0 Convergence history is off default EQ 1 Convergence history is on LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION EPS Set the convergence criteria for the iterative equation solver EQ 0 EPS 1 0e 5 default IHG Set the type of hourglass stabilization to be used with the momentum equations This only applies to the explicit treatment of the momentum equations INSOL 1 EQ 0 IHG 1 default EQ 1 LS DYNA CFD viscous hourglass stabilization EQ 2 y hourglass stabilization viscous form EHG Set the hourglass stabilization multiplier see IHG above EQ 0 EHG 1 0 default Remarks 1 The IMASS variable is only active when INSOL gt 2 on the CONTROL_CFD_GENERAL keyword 2 balancing tensor diffusivity should always be used with the explicit forward Euler treatment of the advection terms This is the default 3 use of the flux limiting procedures
444. ment nodal pairs n3 amp n4 and n7 amp n8 are repeated The ordering is then n1 n2 n3 n3 n4 n5 n6 n6 where nodes n1 n2 n3 form the lower triangular face and nodes n4 n5 n6 for the upper triangular face of the wedge Figure 12 10 Solid 8 node Shell Element 12 42 ELEMENT LS DYNA Version 960 EOS EOS LS DYNA has historically referenced equations of state by type identifiers Below these identifiers are given with the corresponding keyword name in the order that they appear in the manual The equations of state can be used with a subset of the materials that are available for solid elements TYPE 1 TYPE 2 TYPE 3 TYPE 4 TYPE 5 TYPE 6 TYPE 7 TYPE 8 TYPE 9 TYPE 10 TYPE 11 TYPE 14 EOS_LINEAR_POLYNOMIAL EOS JWL EOS SACK TUESDAY EOS GRUNEISEN EOS RATIO OF POLYNOMIALS EOS LINEAR POLYNOMIAL WITH ENERGY LEAK EOS IGNITION AND GROWTH OF REACTION IN HE EOS TABULATED COMPACTION EOS TABULATED EOS PROPELLANT DEFLAGRATION EOS TENSOR PORE COLLAPSE EOS JWLB An additional option TITLE may be appended to all the EOS keywords If this option is used then an addition line is read for each section in 80a format which can be used to describe the equation of state At present LS DYNA does make use of the title Inclusion of titles gives greater clarity to input decks LS DYNA Version 960 13 1 EOS EOS EOS_LINEAR_POLYNOMIAL Purpose Define coefficients for linear polynomial
445. ment should have a node coincident with the retractor but should not be inside the retractor The fed length would typically be set either to a typical element initial length for the distance between painted marks on a real belt for comparisons with high speed film The fed length should be at least three times the minimum length If there are elements initially inside the retractor e2 e3 and e4 in the Figure they should not be referred to on the retractor input but the retractor should be identified on the element input for these elements Their nodes should all be coincident with the retractor node and should not be restrained or constrained Initial slack will automatically be set to 1 1 x minimum length for these elements this overrides any user defined value Weblockers can be included within the retractor representation simply by entering a locking up characteristic in the force pullout curve see Figure 12 3 The final section can be very steep but must have a finite slope LS DYNA Version 960 12 21 ELEMENT ELEMENT Element 1 Before Element es Element 3 x Element 1 Element 2 After Element I Element 4 SS All nodes within this area are coincident Figure 12 2 Elements in a retractor 12 22 ELEMENT LS DYNA Version 960 ELEMENT with weblockers without weblockers aaro PULLOUT Figure 12 3 Retractor force pull characteristics LS DYNA Versio
446. mes Failures can include both the plastic and brittle failures 5 70 CONSTRAINED LS DYNA Version 960 CONSTRAINED 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONSTRAINED SPOTWELD 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Spotweld two nodes 34574 34383 with the approximate strength of a 3 8 SAE Grade No 3 bolt CONSTRAINED SPOTWELD Po PUE M we Se ga SD p ER ora ts MN EE oe ee a a eee nl n2 sn sf n m tf ps 34574 34383 36 0 18 0 2 0 220 10 1 0 sn 36 0 normal failure force is 36 kN Sf 18 0 shear failure force is 18 kN 2 0 normal failure criteria is raised to the power of 2 2 0 shear failure criteria is raised to the power of 2 tf 10 0 failure occurs at time 10 unless strain failure occurs ps 2 0 plastic strain at failure Ur Ur Ur WU Ur UY UY UW Ur UW 5555555555555555555555555555555555555555555555555555555555555555555555555555555 LS DYNA Version 960 5 71 CONSTRAINED CONSTRAINED CONSTRAINED TIE BREAK Purpose Define a tied shell edge to shell edge interface that can release locally as a function of plastic strain of the shells surrounding the interface nodes A rather ductile failure is achieved Card Format VARIABLE DESCRIPTION SNSID Slave node set ID see SET NODE OPTION MNSID Master node set ID see SET NODE OPTION EPPF Plastic str
447. mmy k and rotates it 45 degrees about z axis at the point 0 0 0 0 0 0 2 Transformation id 2000 imports the same dummy model dummy k and translates 1000 units in the x direction 3 Transformation id 3000 imports the same dummy model dummy k and translates 2000 units in the x direction For each DEFINE TRANSFORMATION the commands TRANSL SCALE and ROTATE are available The transformations are applied in the order in which they are defined in the file e g transformation id 1000 in this example would translate scale and then rotate the model INCLUDE TRANSFORM uses a transformation id defined by a DEFINE TRANSFORMATION command to import a model and perform the associated transformations It also allows the user upon importing the model to apply offsets to the various entity ids and perform unit conversion of the imported model 10 26 DEFINE LS DYNA Version 960 KEYWORD DEFINE TRANSFORMATION 1000 option amp TRANSL 5 option amp SCALE 5 option amp ROTATE DEFINE TRANSFORMATION 2000 5 option amp TRANSL DEFINE TRANSFORMATION tranid amp 3000 5 option amp TRANSL dx amp 0000 0 dx amp dx amp 0 00 dx amp 1000 0 dx amp 2000 0 INCLUDE TRANSFORM dummy k Sidnoff amp 0 idroff amp 0 fctmas amp 1 0000 tranid amp 1000 ideoff amp 0 ilctmf amp 0 fcttim amp 1 0000 INCLUDE TRANSFORM dummy k Sidnoff amp 1000000 idro
448. mory specified at execution time Caution is necessary since memory usage is checked after each adaptive step and if the memory usage increases by more than the residual percentage 100 PERCENT the calculation will terminate If the memory environmental variable is set then when the number of words of memory allocated reaches or exceeds this value MEMORY further adaptivity is stopped This option applies to the FORMING contact option only If this flag is set to one 1 the user orientation for the contact interface is used If this flag is set to zero 0 LS DYNA sets the global orientation of the contact surface the first time a potential contact is observed after the birth time If slave nodes are found on both sides of the contact surface the orientation is set based on the principle of majority rules Experience has shown that this principle is not always reliable Adaptivity is stopped if this number of elements is exceeded 1 D3DUMP and RUNRSF files contain all information necessary to restart an adaptive run This did not work in version 936 of LS DYNA 2 Card 2 input is optional and is not required 3 In order for this control card to work the flag ADPOPT 1 must be set in the PART definition Otherwise adaptivity will not function 7 8 CONTROL LS DYNA Version 960 CONTROL 4 In order for adaptivity to work optimally the parameter SNLOG 1 must be set on Optional Control Card B in the CONTACT Section On
449. mputed from the cross product of x and y see Figure 10 1 x X y then the y axis is computed via y2 z Xx Card Format VARIABLE DESCRIPTION CID Coordinate system ID A unique number has to be defined N1 Number of node located at local origin N2 Number of node located along local x axis N3 Number of node located in local x y plane FLAG Set to unity 1 if the local system is to be updated each time step for the BOUNDARY SPC nodal constraints and ELEMENT BEAM type 6 the discrete beam element Generally this option when used with nodal SPC s is not recommended since it can cause excursions in the energy balance because the constraint forces at the node may go through a displacement if the node is partially constrained Remark 1 The nodes N2 and N3 must be separated by a reasonable distance and not colinear to avoid numerical inaccuracies Z N 1 Figure 10 1 Definition of local coordinate system using three nodes LS DYNA Version 960 10 7 DEFINE DEFINE DEFINE COORDINATE SYSTEM Purpose Define a local coordinate system with three points The same procedure as described in Figure 10 1 see DEFINE COORDINATE NODES is used The coordinates of the nodes are given instead Nj is defined by Yo Zo is defined by YL ZL by Xp Yp Zp Card 1 of 2 Required 1 2 3 4 5 6 7 8 e p EHEN EHEN EN e e ELT II Card 2 of 2 Require
450. n Young s Modulus of Steel 210 0E 09 210 0E 03 210 0 Density of Steel 7 85E 03 7 85 09 7 85 06 Yield stress of Mild Steel 200 0E 06 200 0 0 200 Acceleration due to gravity 9 81 9 81E 03 9 81E 03 Velocity equivalent to 30 mph 13 4 13 4E 03 13 4 GENERAL CARD FORMAT The following sections specify for each keyword the cards that have to be defined Each card is defined in its rigid format form and is shown as a number of fields in an 80 character string Most cards are 8 fields with a length of 10 and a sample card is shown below Card Format 1 2 3 4 5 6 7 8 Ree eee ee pur The type is the variable type and is either F for floating point or I for an integer The default gives the value set 1f zero is specified the field is left blank or the card is not defined The remarks refer to comments at the end of the section The card format is given above the card if it is other than eight fields of 10 Free formats may be used with the data separated by commas When using comma format the number of characters used to specify a number must not exceed the number which would fit into the equivalent rigid format field An I8 number is limited to a number of 99999999 and larger numbers with more than eight characters are unacceptable Rigid and free formats can be mixed throughout the deck but not within a card 1 36 INTRODUCTION LS DYNA Versi
451. n 960 VARIABLE VS DS REFL ZSURF FPSID PSID ALPHA GAMMA KTHETA KAPPA XS YS ZS LS DYNA Version 960 LOAD DESCRIPTION Sound speed in fluid Density of fluid Consider reflections from sea floor EQ 0 off EQ 1 on Z coordinate of sea floor if REFL 1 otherwise not used Z coordinate of sea surface Part set ID of parts subject to flood control Use the PART SET COLUMN option where the parameters Al and A2 must be defined as follows Parameter A1 Flooding status EQ 1 0 Fluid on both sides EQ 2 0 Fluid outside air inside EQ 3 0 Air outside fluid inside EQ 4 0 Material or part is ignored Parameter A2 Tubular outer diameter of beam elements For shell elements this input must be greater than zero for loading Part IDs of parts defining the wet surface The elements defining these parts must have there outward normals pointing into the fluid See Figure 19 4 EQ 0 all parts are included GT 0 define NPIDS part ID s below Shock pressure parameter a shock pressure parameter y time constant parameter K time constant parameter K ratio of specific heat capacities X coordinate of charge Y coordinate of charge Z coordinate of charge Weight of charge 19 31 LOAD LOAD VARIABLE DESCRIPTION TDELY Time delay before charge detonates RAD Charge radius CZ Water depth Remarks The pressure history of the primary shockwave at a point in space through wh
452. n 960 12 23 ELEMENT ELEMENT ELEMENT_SEATBELT_SENSOR Purpose Define seat belt sensor Four types are possible see explanation below Card Format 1 2 3 4 5 6 7 8 1 Second Card if SBSTYP 1 1 2 3 4 5 6 7 8 12 24 ELEMENT LS DYNA Version 960 ELEMENT Second Card if SBSTYP 2 SBRID PULRAT PULTIM fo ows Second Card if SBSTYP 3 2 3 4 5 6 7 8 Second Card if SBSTYP 4 2 3 4 5 6 7 8 PEE on LS DYNA Version 960 12 25 ELEMENT ELEMENT VARIABLE DESCRIPTION SBSID SBSTYP SBSFL DOF ACC ATIME SBRID PULRAT PULTIM TIME NIDI NID2 DMX DMN Remarks Sensor ID A unique number has to be used Sensor type EQ 1 EQ 2 EQ 3 EQ 4 acceleration of node retractor pull out rate time distance between nodes Sensor flag 0 sensor active during dynamic relaxation EQ 1 sensor can be triggered during dynamic relaxation Node ID of sensor Degree of freedom EQ 1 x EQ 2 EQ 3 z Activating acceleration Time over which acceleration must be exceeded Retractor ID see ELEMENT_SEATBELT_RETRACTOR Rate of pull out length time units Time over which rate of pull out must be exceeded Time at which sensor triggers Node 110 Node 2 ID Maximum distance Minimum distance 1 Node should not be on rigid body velocity boundary condition o
453. n by EtA Q7 Co DBuByde QB Et A OW KGt A OF where t is the shell thickness The hourglass coefficients QM QB and QW are generally assigned values between 0 05 and 0 10 Finally the hourglass stresses which are updated using the time step Ar from the stress rates in the usual way 1 LS DYNA Version 960 14 3 HOURGLASS HOURGLASS om Q AtO and the hourglass resultant forces are then fa TO B H v TQ _ W fa TQ where the superscript H emphasizes that these are internal force contributions from the hourglass deformations 14 4 HOURGLASS LS DYNA Version 960 INCLUDE INCLUDE Purpose The keyword INCLUDE provides a means of reading independent input files containing model data The file contents are placed directly at the location of the INCLUDE line INCLUDE_ OPTION Generally the INCLUDE command is used without any options however two options are available INCLUDE_STAMPED_PART INCLUDE_TRANSFORM The STAMPED_PART option allows the plastic strain and thickness distribution of the stamping simulation to be mapped onto a part in the crash model Between the stamped part and the crash part note the following points 1 The the outer boundaries of the parts do not need to match since only the regions of the crash part which overlap the stamped part are initialized 2 Arbitrary mesh patterns are assumed
454. n has been available in the MPP contact for some time This input can be defined on the fourth card of the CONTROL CONTACT input and on each contact definition on the third optional card in the CONTACT definitions e If the average acceleration flag is active the average acceleration for rigid body nodes is now written into the D3THDT and NODOUT files In previous versions of LS DYNA the accelerations on rigid nodes were not averaged e A capability to initialize the thickness and plastic strain in the crash model is available through the option INCLUDE STAMPED PART which takes the results from the LS DYNA stamping simulation and maps the thickness and strain distribution onto the same part with a different mesh pattern e A capability to include finite element data from other models is available through the option INCLUDE_TRANSFORM This option will take the model defined in an INCLUDE file offset all ID s translate rotate and scale the coordinates and transform the constitutive constants to another set of units LS DYNA Version 960 1 11 INTRODUCTION INTRODUCTION DESCRIPTION OF KEYWORD INPUT The keyword input provides a flexible and logically organized database that is simple to understand Similar functions are grouped together under the same keyword For example under the keyword ELEMENT are included solid beam shell elements spring elements discrete dampers seat belts and lumped masses LS DYNA User s Manual is al
455. n option was provided for storing element data on disk thereby doubling the capacity of DYNA3D The 1982 version of DYNA3D Hallquist 1982 accepted DYNA2D Hallquist 1980 material input directly The new organization was such that equations of state and constitutive models of any complexity could be easily added Complete vectorization of the material models had been nearly achieved with about a 10 percent increase in execution speed over the 1981 version In the 1986 version of DYNA3D Hallquist and Benson 1986 many new features were added including beams shells rigid bodies single surface contact interface friction discrete springs and dampers optional hourglass treatments optional exact volume integration and VA X VMS IBM UNIX COS operating systems compatibility that greatly expanded its range of applications DYNA3D thus became the first code to have a general single surface contact algorithm In the 1987 version of DYNA3D Hallquist and Benson 1987 metal forming simulations and composite analysis became a reality This version included shell thickness changes the Belytschko Tsay shell element Belytschko and Tsay 1981 and dynamic relaxation Also included were non LS DYNA Version 960 INTRODUCTION INTRODUCTION reflecting boundaries user specified integration rules for shell and beam elements a layered composite damage model and single point constraints New capabilities added in the 1988 DYNA3D Hallquist 1988
456. n types 3 5 10 13 and 26 contact Force transducers to obtain reaction forces in automatic contact definitions Defined manually via segments or automatically via part ID s Searching depth can be defined as a function of time Bucket sort frequency can be defined as a function of time Interior contact for solid foam elements to prevent negative volumes Locking joint Version 960 1 5 INTRODUCTION INTRODUCTION Temperature dependent heat capacity added to Wang Nefske inflator models Wang Hybrid inflator model Wang 1996 with jetting options and bag to bag venting Aspiration included in Wang s hybrid model Nusholtz Wang Wylie 1996 Extended Wang s hybrid inflator with a quadratic temperature variation for heat capacities Nusholtz 1996 Fabric porosity added as part of the airbag constitutive model Blockage of vent holes and fabric in contact with structure or itself considered in venting with leakage of gas Option to delay airbag liner with using the reference geometry until the reference area is reached Birth time for the reference geometry Multi material Euler ALE fluids 2nd order accurate formulations Automatic coupling to shell brick or beam elements Coupling using LS DYNA contact options Element with fluid void and void material Element with multi materials and pressure equilibrium Nodal inertia tensors 2D plane stress plane strain rigid and axisymmetric elements
457. nal energy Pressure is defined by p C e yT e E in the loading phase The volumetric strain ey is given by the natural logarithm of the relative volume Unloading occurs along the unloading bulk modulus to the pressure cutoff Reloading always follows the unloading path to the point where unloading began and continues on the loading path see Figure 13 1 Up to 10 points and as few as 2 may be used when defining the tabulated functions LS DYNA will extrapolate to find the pressure if necessary pressure The bulk unloading modulus is a function of volumetic strain Volumetric strain i 1 tension cutoff Figure 13 1 Pressure versus volumetric strain curve for Equation of state Form 8 with compaction In the compacted states the bulk unloading modulus depends on the peak volumetric strain LS DYNA Version 960 13 19 EOS EOS EOS_TABULATED This is Equation of state Form 9 Card Format Card 1 3 4 5 6 7 8 Card Format 5E16 0 Card 2 2 3 4 5 Card 3 fe os Repeat Cards 2 and 3 for C T A total of 7 cards must be defined VARIABLE DESCRIPTION EOSID Equation of state label eV1 eV2 eVN In V C1 C2 CN T1 T2 TN 13 20 EOS LS DYNA Version 960 EOS VARIABLE DESCRIPTION GAMA y EO Initial internal energy VO Initial relative volume Remarks The tabulated equation of state model is linear
458. nalty stiffness is too large If instabilities occur the recommended way to eliminate these problems is to decrease the time step or reduce the scale factor on the penalties For cylindrical joints by setting node 3 to zero it is possible to use a cylindrical joint to join a node that is not on a rigid body node 1 to a rigid body nodes 2 and 4 Card 1 Required Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION N1 Node 1 in rigid body A Define for all joint types N2 Node 2 in rigid body B Define for all joint types N3 Node 3 in rigid body A Define for all joint types except SPHERICAL N4 Node 4 in rigid body B Define for all joint types except SPHERICAL N5 Node 5 in rigid body A Define for joint types TRANSLATIONAL LOCKING ROTATIONAL_MOTOR CONSTANT_VELOCITY GEARS RACK_AND_PINION PULLEY and SCREW N6 Node 6 in rigid body B Define for joint types TRANSLATIONAL LOCKING ROTATIONAL_MOTOR CONSTANT_VELOCITY GEARS RACK_AND_PINION PULLEY and SCREW RPS Relative penalty stiffness default 1 0 DAMP Damping scale factor on default damping value Revolute and Spherical Joints EQ 0 0 default is set to 1 0 LE 0 01 and GT 0 0 no damping is used LS DYNA Version 960 5 25 CONSTRAINED CONSTRAINED Card 2 Required for joint types MOTOR GEARS RACK AND PINION PULLEY and SCREW only Card 1 1 VARIABLE DESCRIPTION PARM Parameter which a function of joint type Leave blank for MOT
459. nate gaps in the surface More user control over contact defaults Improved interpenetration warnings printed in automatic contact Flag for using actual shell thickness in single surface contact logic rather than the default Definition by exempted part ID s Airbag to Airbag venting segmented airbags are now supported 1 4 INTRODUCTION LS DYNA Version 960 INTRODUCTION Airbag reference geometry speed improvements by using the reference geometry for the time step size calculation Isotropic airbag material may now be directly for cost efficiency Airbag fabric material damping is specified as the ratio of critical damping Ability to attach jets to the structure so the airbag jets and structure to move together PVM 5 1 Madymo coupling is available Meshes are generated within LS DYNA3D for all standard contact entities Joint damping for translational motion Angular displacements rates of displacements damping forces etc in JNTFORC file Link between LS NIKE3D to LS DYNA3D via INITIAL_STRESS keywords Trim curves for metal forming springback Sparse equation solver for springback Improved mesh generation for IGES and VDA provides a mesh that can directly be used to model tooling in metal stamping analyses added in 1996 1997 in Version 940 LS DYNA Part Material ID s may be specified with 8 digits Rigid body motion can be prescribed in a local system fixed to rigid body Nonlinear least squares fit
460. nd correlations according to the level of statistics requested Note that the time averaged Statistics are only available for analyses that solve the time dependent Navier Stokes equations For ISTATS 1 the time averages of the following variables are placed in the database X velocity Y velocity Z velocity Temperature Pressure X vorticity Y vorticity Z vorticity Stream Function Density Species 1 Concentration Species 10 Concentration For ISTATS 2 the database includes the time average quantities specified with ISTATS 1 as well as X velocity Y velocity and Z velocity correlations with the following variables X velocity Y velocity Z velocity Temperature Pressure Species 1 Concentration Species 10 Concentration For ISTATS 3 the database includes the time average quantities specified with ISTATS 1 and ISTATS 2 as well as time average of the following variables ux 053 t LS POST derives the following additional quantities for each level of statistics For ISTATS 1 velocity magnitude enstrophy and helicity are added For ISTATS 2 turbulent kinetic energy Reynolds Stresses and fluctuations of other velocity correlation quantities are added For ISTATS 3 velocity skewness and velocity flatness are added For further details on these mean statistical quantities see Chapter 8 Flow Statistics in LS DYNA s Incompressible Flow Solver User s Manual LS DYNA Version 960
461. ndary jet focal point Gaussian profile Virtual origin Node 2 gt Figure 1 1 Jetting configuration for a driver s side airbag pressure applied only if centroid of surface is in line of sight and b the passenger s side bag 1 22 AIRBAG LS DYNA Version 960 AIRBAG Jet Focal Point Figure 1 2 Multiple jet model for driver s side airbag Relative jet velocity V degrees cutoff angle Figure 1 3 Normalized jet velocity versus angle for multiple jet driver s side airbag LS DYNA Version 960 1 23 AIRBAG AIRBAG Further additional required for CM option The following additional card is defined for the WANG_NEFSKE_JETTING_CM and WANG_ NEFSKE_MULTIPLE_JETTING_CM options Additional card required for _CM option Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NREACT Node for reacting jet force If zero the jet force will not be applied Remarks Compared with the standard LS DYNA jetting formulation the Constant Momentum option has several differences Overall the jetting usually has a more significant effect on airbag deployment than the standard LS DYNA jetting the total force is often greater and does not reduce with distance from the jet The velocity at the jet outlet is assumed to be a choked sonic adiabatic flow of a perfect gas Therefore the velocity at the outlet is given by Voutlet 7 VOR The density in the nozzle is then calculated from conservation of mass flow
462. nectivities for all elements which include shells beams solids thick shells springs dampers seat belts and concentrated masses in LS DYNA EOS This section reads the equations of state parameters The equation of state identifier EOSID points to the equation of state identifier on the PART card HOURGLASS Defines hourglass and bulk viscosity properties The identifier HGID on the HOURGLASS card refers to HGID on PART card INCLUDE To make the input file easy to maintain this keyword allows the input file to be split into subfiles Each subfile can again be split into sub subfiles and so on This option is beneficial when the input data deck is very large INITIAL Initial velocity and initial momentum for the structure can be specified in this section The initial velocity specification can be made by INITIAL_VELOCITY_NODE card or INITIAL_ VELOCITY cards In the case of VELOCITY NODE nodal identifiers are used to specify the velocity components for the node Since all the nodes in the system are initialized to zero only the nodes with non zero velocities need to be specified The INITIAL_VELOCITY card provides the capability of being able to specify velocities using the set concept or boxes INTEGRATION In this section the user defined integration rules for beam and shell elements are specified IRID refers to integration rule number IRID on SECTION_BEAM and SECTION_SHELL cards respectively Quadra
463. ned Angles in the master side of a slideline that approach 90 must be avoided Whenever such angles exist in a master surface two or more slidelines should be defined This procedure is illustrated in Figure 6 5 An exception for the foregoing rule arises if the surfaces are tied In this case only one slideline is needed Whenever two surfaces are in contact the smaller of the two surfaces should be used as the slave surface For example in modeling a missile impacting a wall the contact surface on the missile should be used as the slave surface Care should be used when defining a master surface to prevent the extension from interfering with the solution In Figures 6 6 and 6 7 slideline extensions are shown Version 960 6 63 CONTACT CONTACT Master surface nodes my m5 Slave surface nodes s 524 MG mj ms 6 m7 Mg mi4 1 2 Slaves Masters Slaves Masters Slaves Masters 51 mj 11 m 24 1114 52 m 812 m7 823 1113 mg 4 m14 14 mo 811 mg S24 815 1115 Figure 6 5 Proper definition of illustrated slave master surface requires three slidelines note that slave surface is to the left of the master surface as one moves along master nodes in order of definition 6 64 CONTACT LS DYNA Version 960 CONTACT Better1 This is the extension if node mgis included in the master surface definition Poort This extension may interfere with slave nodes to 52 and le
464. nf and a restart dump named d3dump01 is created A new input file job2 inf is generated and submitted as a restart with R d3dump01 as the dump file The input file job2 inf contains the entire model in its original undeformed state but with more contact surfaces new output databases and so on Since this is a restart job information must be given to tell LS DYNA which parts of the model should be initialized in the full deck restart When the calculation begins the restart database contained in the file d3dump01 is read and a new database is created to initialize the model in the input file job2 inf The data in file job2 inf is read and the LS DYNA proceeds through the entire input deck and initialization At the end of the initialization process all the parts selected are initialized from the data saved from d3dump01 This means that the deformed position and velocities of the nodes on the elements of each part and the LS DYNA Version 960 1 31 INTRODUCTION INTRODUCTION stresses and strains in the elements and if the material of the part is rigid the rigid body properties will be assigned It is assumed during this process that any initialized part has the same elements in the same order with the same topology in jobl and job2 If this is not the case the parts cannot be initialized However the parts may have different identifying numbers For discrete elements and seat belts the choice is all or nothing All discrete and belt el
465. ng is important THEORY Default shell theory EQ 1 Hughes Liu EQ 2 Belytschko Tsay default EQ 3 BCIZ triangular shell not recommended EQ 4 C triangular shell EQ 5 Belytschko Tsay membrane EQ 6 S R Hughes Liu EQ 7 S R co rotational Hughes Liu EQ 8 Belytschko Leviathan shell EQ 9 fully integrated Belytschko Tsay membrane EQ 10 Belytschko Wong Chiang EQ 11 Fast co rotational Hughes Liu EQ 12 Plane stress x y plane EQ 13 Plane strain x y plane EQ 14 Axisymmetric solid y axis of symmetry area weighted EQ 15 Axisymmetric solid y axis of symmetry volume weighted EQ 16 Fully integrated shell element very fast EQ 17 Discrete Kirchhoff triangular shell DKT EQ 18 Discrete Kirchhoff linear shell either quadrilateral or triangular EQ 20 C linear shell element with drilling stiffness For the 2D axisymmetric solid elements high explosive applications work best with the area weighted approach and structural applications work best with the volume weighted approach The volume weighted approach can lead to problems along the axis of symmetry under very large deformations Often the symmetry condition is not obeyed and the elements will kink along the axis The volume weigthed approach must be used if 2D shell elements are used in the mesh Type 14 and 15 elements cannot be mixed in the same calculation BWC Warping stiffness for Belytschko Tsay shells EQ 1 Belytschko Wong Chiang warping stiffness
466. ng the axis of the jet NODE3 Optional node ID located at secondary jet focal point Remarks 1 Itis assumed that the jet direction is defined by the coordinate method XJFP YJFP ZJFP and XJVH YJVH ZJVH unless both NODEI and NODE2 are defined In which case the coordinates of the nodes give by NODEI NODE2 and NODE3 will override XJFP YJFP ZJFP and XJVH YJVH ZJVH The use of nodes is recommended if the airbag system is undergoing rigid body motion The nodes should be attached to the vehicle to allow for the coordinates of the jet to be continuously updated with the motion of the vehicle The jetting option provides a simple model to simulate the real pressure distribution in the airbag during the breakout and early unfolding phase Only the sufaces that are in the line of sight to the virtual origin have an increased pressure applied With the optional load curve LCRJV the pressure distribution with the code can be scaled according to the so called relative jet velocity distribution LS DYNA Version 960 1 33 AIRBAG AIRBAG For passenger side airbags the cone is replaced by a wedge type shape The first and secondary jet focal points define the corners of the wedge and the angle then defines the wedge angle Instead of applying pressure to all surfaces in the line of sight of the virtual origin s a part set can be defined to which the pressure is applied 2 This variable is not used and has been included to mainta
467. ngback can be activated in the original LS DYNA input deck or later using a small restart input deck In this way the user can decide to continue a previous forming analysis by restarting to add the implicit springback phase Another alternative approach to springback simulation is to use the keyword INTERFACE SPRINGBACK DYNAJ3D to generate a dynain file after forming and then perform a second simulation running LS DYNA in fully implicit mode for springback See Appendix M for a description of how to run an implicit analysis using LS DYNA The implict springback phase begins when the forming simulation termination time ENDTIM is reached as specified with the keyword CONTROL TERMINATION Since the springback phase is static its termination time can be chosen arbitrarily unless material rate effects are included The default choice is 2 0 ENDTIM and can be changed using the CONTROL IMPLICIT GENERAL key word 18 8 INTERFACE LS DYNA Version 960 INTERFACE Since the springback analysis is a static simulation a minimum number of essential boundary conditions or Single Point Constraints SPC s are required to prohibit rigid body motion of the part These boundary conditions can be added for the springback phase using the input option on the INTERFACE SPRINGBACK SEAMLESS keyword above Several new CONTROL IMPLICIT keywords have been added to control the implicit springback phase These keywords can also be added to a restart input deck
468. ning cone angle as a function of time LCJRV Load curve ID giving the spatial jet relative velocity distribution see Figures 1 2 and 1 3 The jet velocity is determined from the inflow mass rate and scaled by the load curve function value corresponding to the value of the angle y Typically the values on the load curve vary between 0 and unity See DEFINE CURVE BETA Efficiency factor B which scales the final value of pressure obtained from Bernoulli s equation LT 0 0 IBI is the load curve ID defining the efficiency factor as a function of time 1 20 AIRBAG LS DYNA Version 960 AIRBAG VARIABLE DESCRIPTION XSJFP x coordinate of secondary jet focal point passenger side bag If the coordinates of the secondary point are 0 0 0 then a conical jet driver s side airbag is assumed YSJFP y coordinate of secondary jet focal point ZSJFP z coordinate of secondary jet focal point PSID Optional part set ID see SET PART If zero all elements are included in the airbag ANGLE Cutoff angle in degrees The relative jet velocity is set to zero for angles greater than the cutoff See Figure 1 3 This option applies to the MULTIPLE jet only NODEI Node ID located at the jet focal point i e the virtual origin in Figure 1 1 See Remark 1 below NODE2 Node ID for node along the axis of the jet NODE3 Optional node ID located at secondary jet focal point Remarks 1 Itis assumed that the jet direction is defined by the coor
469. node N3 see Figure 3 2 MLC4 Curve multiplier at node N4 see Figure 3 2 Remarks Three definitions for heat flux are possible Heat flux can be a function of time a function of temperature or constant values that are maintained throughout the calculation With the definition of multipliers at each node of the segment a bilinear spatial variation can be assumed By convention heat flow is negative in the direction of the surface outward normal vector Surface definition is in accordance with the left hand rule The outward normal vector points to the left as one progresses from node N1 ND N3 N4 See Figure 3 6 3 20 BOUNDARY LS DYNA Version 960 LS DYNA Version 960 BOUNDARY q4 92 n2 n4 nl Figure 3 6 Nodal number determines outward normal 3 21 BOUNDARY BOUNDARY BOUNDARY MCOL Purpose Define parameters for MCOL coupling The MCOL Program is a rigid body mechanics program for modeling the dynamics of ships See Remark 1 for more information Card Format 1 2 3 4 5 6 7 8 LT Card 2 must be defined for each ship Card 2 1 2 3 4 5 p VARIABLE DESCRIPTION NMCOL Number of ships in MCOL coupling MXSTEP Maximum of time step in MCOL calculation If the number of MCOL time steps exceeds MXSTEP then LS DYNA will terminate ENDTMCOL Uncoupling termination time see Remark 2 below EQ 0 0 set to LS DYNA termination time 3 22 BOUNDARY LS DY
470. nodes of solid elements are retained and continue to be active in contact EQ 2 the eroding nodes of solid and shell elements are retained and continue to be active in contact USRSTR Storage per contact interface for user supplied interface control subroutine see Appendix D If zero no input data is read and no interface storage is permitted in the user subroutine This storage should be large enough to accommodate input parameters and any history data This input data is available in the user supplied subroutine USRFRC Storage per contact interface for user supplied interface friction subroutine see Appendix E If zero no input data is read and no interface storage is permitted in the user subroutine This storage should be large enough to accommodate input parameters and any history data This input data is available in the user supplied subroutine NSBCS Number of cycles between contact searching using three dimensional bucket searches Defaults recommended INTERM Flag for intermittent searching in old surface to surface contact using the interval specified as NSBCS above EQ 0 off EQ 1 on LS DYNA Version 960 7 31 CONTROL CONTROL VARIABLE XPENE SSTHK ECDT TIEDPRJ SFRIC DFRIC EDC VFC TH TH_SF PEN_SF IGNORE FRCENG 7 32 CONTROL DESCRIPTION Contact surface maximum penetration check multiplier If the small penetration checking option PENCHK on the contact surface control card
471. ns EQ 6 constrained x and z translations EQ 7 constrained x y and z translations RC Rotational Constraint EQ 1 constrained x rotation EQ 2 constrained y rotation EQ 3 constrained z rotation EQ 4 constrained x and y rotations EQ 5 constrained z rotations EQ 6 constrained z and x rotations EQ 7 constrained x y and z rotations DIR Direction of normal EQ 1 global x EQ 2 global y EQ 3 global x X x offset coordinate Y y offset coordinate Z z offset coordinate 5 18 CONSTRAINED LS DYNA Version 960 CONSTRAINED Remarks Nodes within a mesh size dependent tolerance are constrained on a global plane This option is recommended for use with r method adaptive remeshing where nodal constraints are lost during the remeshing phase LS DYNA Version 960 5 19 CONSTRAINED CONSTRAINED CONSTRAINED INTERPOLATION Purpose Define an interpolation constraint With this constraint type the motion of a single dependent node is interpolated from the motion of a set of independent nodes This option is useful for the load redistribution of a load which can be either a translational force or moment applied to the dependent node to the surrounding independent nodes and it can also be used to model shell brick and beam brick interfaces The mass and rotary inertia of the dependent nodal point is also redistributed This constraint is applied in the global coordinate system One CONSTRAINED
472. ns sometimes seen in honeycomb materials In formulation 0 the local coordinate system follows the element rotation whereas in formulation 9 the local coordinate system is based on axes passing through the centroids of the element faces Formulation 0 is preferred for severe shear deformation where the barrier is fixed in space If the barrier is attached to a moving body which can rotate then formulation 9 is usually preferred 5 selective reduced integrated solid element element type 2 assumes that pressure is constant throughout the element to avoid pressure locking during nearly incompressible flow However if the element aspect ratios are poor shear locking will lead to an excessively stiff response A better choice given poor aspect ratios is the one point solid element which work well for implicit and explicit calculations For linear statics the type 18 enhanced strain element works well with poor aspect ratios Please note that highly distorted elements should always be avoided since excessive stiffness will still be observed even in the enhanced strain strain formulations 23 22 SECTION LS DYNA Version 960 SECTION 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 SECTION SOLID 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 A bolt modeled with solids was found to have excessive hourglassing Thus the section sid 116 asso
473. nt 1 219 term EN Pressure Exponent 214 term FMXGR Maximum F for 18 term FMNGR Minimum F for 204 term Remarks A deflagration burn rate reactive flow model requires an unreacted solid equation of state a reaction product equation of state a reaction rate law and a mixture rule for the two or more species The mixture rule for the standard ignition and growth model Lee and Tarver 1980 assumes that both pressures and temperatures are completely equilibrated as the reaction proceeds However the mixture rule can be modified to allow no thermal conduction or partial heating of the solid by the reaction product gases For this relatively slow process of airbag propellant burn the thermal and pressure equilibrium assumptions are valid The equations of state currently used in the burn model are the JWL Gruneisen the van der Waals co volume and the perfect gas law but other equations of state can be easily implemented In this propellant burn the gaseous nitrogen produced by the burning sodium azide obeys the perfect gas law as it fills the airbag but may have to be modelled as a van der Waal s gas at the high pressures and temperatures produced in the propellant chamber The chemical reaction rate law is pressure particle geometry and surface area dependant as are most high pressure burn processes When the temperature profile of the reacting system is well known temperature dependent Arrhenius chemical kinetics can be used Sin
474. nteractive sense switches lt ctrl c gt nlprt and lt ctrl c gt iter The arc length method can be controlled based on the displacement of a single node in the model For example in dome reversal problems the node at the center of the dome can be used By default the generalized arc length method is used where the norm of the global displacement vector controls the solution This includes all nodes In many cases the arc length method has difficulty tracking the load displacement curve through critical regions Using O lt ARCLEN lt I will reduce the step size to assist tracking the load displacement curve with more accuracy Use of ARCLEN lt 1 will cause more steps to be taken Suggested values are 1 0 the defalut 0 5 0 25 and 0 10 Some static problems exhibit oscillatory response near instability points This option numerically supresses these oscillations and may improve the convergence behavior of the post buckling solution 7 54 CONTROL LS DYNA Version 960 CONTROL CONTROL_IMPLICIT_SOLVER Purpose Define control parameters for the implicit analysis linear equation solver The linear equation solver performs the CPU intensive stiffness matrix inversion Card Format 1 2 3 4 5 6 7 8 LSOLVR LPRINT NEGEV ORDER DRCM DRCPRM AUTOSPC AUTOTOL 2 22191 see remarks below VARIABLE DESCRIPTION LSOLVR Linear equation solver method EQ 1 direct sparse incore with automatic out
475. ntion EQ 6 part set ID for exempted parts All non exempted parts are included in the contact MSTYP Master segment set type The type must correlate with the number specified for MSID EQ 0 segment set ID EQ 1 shell element set ID EQ 2 part set ID EQ 3 part ID LS DYNA Version 960 6 7 CONTACT CONTACT Card 1 continued VARIABLE DESCRIPTION SBOXID BOXID Include only slave nodes segments within specified box see DEFINE BOX in contact definition Only applies when SSID is defined by PART or PART SET MBOXID BOXID Include only master segments within specified box see DEFINE BOX in contact Only applies when MSID is defined by PART or PART SET SPR Include the slave side in the DATABASE NCFORC and the DATABASE BINARY INTFOR interface force files EQ 1 slave side forces included MPR Include the master side in the DATABASE NCFORC and the DATABASE BINARY INTFOR interface force files EQ 1 master side forces included Remarks 1 Giving a slave set ID equal to zero is valid only for the single surface contact algorithms i e the options SINGLE SURFACE and the AUTOMATIC AIRBAG and ERODING SINGLE SURFACE options 2 A master set ID is not defined for the single surface contact algorithms including AUTOMATIC GENERAL or FORCE TRANSDUCERS 6 8 CONTACT LS DYNA Version 960 CONTACT Card 2 is mandatory for all contact types Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION
476. nto the rigid body such that overall momentum is conserved It is intended that the rigid body is embedded within the moving object 2 Vibrations at frequencies below FREQ are damped by more than CDAMP while those at frequencies above FREQ are damped by less than CDAMP It is recommended that FREQ be set to the frequency of the lowest mode of vibration LS DYNA Version 960 8 7 DAMPING DAMPING 8 8 DAMPING LS DYNA Version 960 DATABASE DATABASE The database definitions are optional but are necessary to obtain output files containing results information In this section the database keywords are defined in alphabetical order DATABASE OPTION DATABASE BINARY OPTION DATABASE CROSS SECTION OPTION DATABASE EXTENT OPTION DATABASE FORMAT DATABASE HISTORY OPTION DATABASE NODAL FORCE GROUP DATABASE SPRING FORWARD DATABASE SUPERPLASTIC FORMING DATABASE TRACER The ordering of the database definition cards in the input file is competely arbitrary LS DYNA Version 960 9 1 DATABASE DATABASE DATABASE_OPTION Options for ASCII files include if the file is not specified it will not be created ABSTAT Airbag statistics AVSFLT AVS database See DATABASE EXTENT OPTION BNDOUT Boundary condition forces and energy DEFGEO Deformed geometry file Note that to output this file in Chrysler format insert the following line in your cshrc file setenv LSTC_DEFGEO chrysler NASBDF file NASTRAN Bulk Dat
477. o create too many If DATABASE BINARY D3PLOT is not specified in the keyword deck then a complete output state will be written ever timestep The D3PLOT D3PART D3DRLF and the INTFOR files contain plotting information to plot data over the three dimensional geometry of the model These databases can be plotted with LS POST The D3THDT file contains time history data for element subsets as well as global information see DATABASE HISTORY This data can be plotted with LS POST The default names for the D3PLOT D3PART D3DRLF and the D3THDT files are D3PLOT D3PART D3DRLF and D3THDT For INTFOR a unique name must be specified on the execution line with S iff iff file name see the INTRODUCTION EXECUTION SYNTAX The file structure is such that each file contains the full geometry at the beginning followed by the analysis generated output data at the specified time intervals The default file size of 7000000 octal words may be much to small to hold one complete output state when models are very large and an excessive number of files may be created The limit of LS DYNA to create files is 99 family members Therefore it is recommended that the file size be adjusted on the execution line with the X scl scl is a scale factor to enlarge the family member size For the contents of the D3PLOT D3PART and D3THDT files see also the DATABASE EXTENT BINARY definition It is possible to severely restrict the information that is dumped and consequently re
478. o on The constitutive constants are defined in the MAT section where constitutive data is defined for all element types including solids beams shells thick shells seat belts springs and dampers Equations of state which are used only with certain MAT materials for solid elements are defined in the EOS section Since many elements in LS DYNA use uniformly reduced numerical integration zero energy deformation modes may develop These modes are controlled numerically by either an artificial stiffness or viscosity which resists the formation of these undesirable modes The hourglass control can optionally be user specified using the input in the HOURGLASS section During the keyword input phase where data is read only limited checking is performed on the data since the data must first be counted for the array allocations and then reordered Considerably more checking is done during the second phase where the input data is printed out Since LS DYNA has retained the option of reading older non keyword input files we print out the data into the output file D3HSP default name as in previous versions of LS DYNA An attempt is made to complete the input phase before error terminating if errors are encountered in the input Unfortunately this is not always possible and the code may terminate with an error message The user should always check either output file D3HSP or MESSAG for the word Error NID X Y Z b ELEMENT EID PI
479. ode to surface contacts can be used to activate an automatic part switch Contact surface and rigid wall numbers are the order in which they are defined in the deck The first rigid wall and the first contact surface encountered in the input deck will have an entity number of 1 Switch sets may be paired together to allow a pair of switches to be activated more than once Each pair of switches should use consistant values for CODE i e 1 amp 3 or 2 amp 4 Within each pair of switches the related switch RELSW should be set to the ID of the other switch in the pair The Master switch PAIRED 1 will be activated before the Slave switch PAIRED 1 If the delete switch is activated ALL corresponding constraints are deactivated regardless of their relationshiop to a switched part By default constraints which are directly associated with a switched part are deactivated activated as necessary Define a pair or related switches that will be activated by no force on Contact 3 To start with switch set 20 will be activated PAIRED 1 swapping 5 the PARTS to RIGID When the contact force is none zero switch set 10 will be activated swapping the PARTS to DEFORMABLE If the contact force returns to 6 zero switch set 20 will be activated again making the PARTS RIGID DEFORMABLE TO RIGID AUTOMATIC Oe alee ln De de Sean Des ann nn esso 5 swset code time 1 time 2 time 3 entno relsw paired 20 2 3 10 al nrbf ncsf rwf dtmax D2R
480. of Papadrakakis Papadrakakis 1981 EQ 0 not active EQ 1 active EDTTL Convergence tolerance on automatic control of dynamic relaxation LS DYNA Version 960 7 37 CONTROL CONTROL VARIABLE DESCRIPTION IDRFLG Dynamic relaxation flag for stress initialization EQ 999 dynamic relaxation not activated even if specified on a load curve see DEFINE CURVE EQ 1 dynamic relaxation is activated and time history output is produced during dynamic relaxation see Remark 2 below EQ 0 not active EQ 1 dynamic relaxation is activated EQ 2 initialization to a prescribed geometry see Remark 1 below Remarks 1 Stress initialization in LS DYNA for small strains may be accomplished by linking to implicit code option 2 A displacement state is required that gives for each nodal point its label xyz displacements xyz rotations and temperature This data is read from unit 7 m with the format 18 7e15 0 See also INTRODUCTION Execution Syntax 2 If IDRFLG is set to 1 the dynamic relaxation proceeds as normal but time history data is written to the D3THDT file in addition to the normal data being writen to the D3DRLE file At the end of dynamic relaxation the problem time is reset to zero However information is written to the D3THDT file with an increment to the time value The time increment used is reported at the end of dynamic relaxation 7 38 CONTROL LS DYNA Version 960 CONTROL CONTROL_ENERGY Purpos
481. of core EQ 3 direct sparse double precision EQ 4 SMP parallel multi frontal sparse solver 2 default EQ 5 SMP parallel multi frontal sparse solver 2 double precision EQ 6 BCSLIB EXT direct sparse double precision EQ 10 iterative best of currently available iterative methods EQ 11 iterative Conjugate Gradient method EQ 12 iterative CG with Jacobi preconditioner EQ 13 iterative CG with Incomplete Choleski preconditioner EQ 14 iterative Lanczos method EQ 15 iterative Lanczos with Jacobi preconditioner EQ 16 iterative Lanczos with Incomplete Choleski preconditioner LPRINT Linear solver print flag 0 no printing EQ 1 summary statistics on memory cpu time and iteration count EQ 2 more statistics EQ 3 even more statistics and debug checking e g residual of eigenvalues and eigenvectors NOTE during execution sense switch Iprint can also be used to toggle this print flag on and off NEGEV Negative eigenvalue flag Selects procedure when negative eigenvalues are detected during stiffness matrix inversion EQ 1 stop or retry step EQ 2 print warning message try to continue default LS DYNA Version 960 7 55 CONTROL CONTROL VARIABLE DESCRIPTION ORDER DRCM DRCPRM AUTOSPC AUTOTOL Remarks LSOLVR LPRINT Ordering option EQ 0 method set automatically by LS DYNA EQ 1 MMD Multiple Minimum Degree EQ 2 Metis Drilling rotation constraint methoc EQ 1 add stiffnes
482. of time steps between updating the list of active elements default 200 The list update can be quite expensive and should be done at a reasonable interval The default is not be appropiate for all problems 1 The part ID must consist of 3D shell elements 19 18 LOAD LS DYNA Version 960 LOAD LOAD_NODE_OPTION Options include POINT SET Purpose Apply a concentrated nodal force to anode or a set of nodes Card Format VARIABLE DESCRIPTION NODE NSID Node ID or nodal set ID NSID see SET_NODE_OPTION DOF Applicable degrees of freedom EQ 1 x direction of load action EQ 2 y direction of load action EQ 3 z direction of load action EQ 4 follower force see remark 2 on next page EQ 5 moment about the x axis EQ 6 moment about the y axis EQ 7 moment about the z axis EQ 8 follower moment LCID Load curve ID see DEFINE_CURVE SF Load curve scale factor CID Coordinate system ID optional see remark 1 on next page LS DYNA Version 960 19 19 LOAD LOAD VARIABLE DESCRIPTION MI Node 1 ID Only necessary if DOF EQ 4 or 8 see remark 2 below M2 Node 2 ID Only necessary if DOF EQ 4 or 8 see remark 2 below M3 Node 3 ID Only necessary if DOF EQ 4 or 8 see remark 2 below Remarks I The global coordinate system is the default The local coordinate system ID s are defined in the DEFINE COORDINATE SYSTEM section 2 Nodes 2 must be defined for a follower force A positiv
483. older formats Complex surface treatment including NURB surfaces Parametric modeling Capabilities specialized to automotive applications Airbag folding and inspection Occupant positioning Seat belt positioning both beam and shells Merging of occupants airbags and belts with car models LS POST LS POST processes output from LS DYNA LS POST reads the binary plot files generated by LS DYNA and plots contours fringes time histories and deformed shapes Color contours and fringes of a large number of quantities may be interactively plotted on meshes consisting of plate shell and solid type elements LS POST can compute a variety of strain measures reaction forces along constrained boundaries and momenta LS POST is operational on the CRAY SUN DEC IBM RS6000 SGI HP and PC computers LS DYNA generates three binary databases One contains information for complete states at infrequent intervals 50 to 100 states of this sort is typical ina LS DYNA calculation The second contains information for a subset of nodes and elements at frequent intervals 1000 to 10 000 states is typical The third contains interface data for contact surfaces Because of the difficulty in handling one large file an alternative method for obtaining printed output is also available Many ASCII databases are created at the user s option containing such information as cross sectional forces rigidwall forces nodal point data element integration point
484. olid elements EQ 0 the default is set to 8 EQ 1 one point quadrature is used EQHEAT Mechanical equivalent of heat e g 1 J N m eq 0 default set to 1 FWORK Fraction of mechnical work converted into heat eq 0 default set to 1 SBC Stefan Boltzmann constant Value is used with enclosure radiation surfaces see BOUNDARY RADIATION 7 78 CONTROL LS DYNA Version 960 CONTROL Remark 1 Use of a direct solver e g solver 1 is usually less efficient than an iterative solver Solver 1 should be tried if convergence problems occur with an iterative solver LS DYNA Version 960 7 79 CONTROL CONTROL CONTROL_THERMAL_TIMESTEP Purpose Set timestep controls for the thermal solution in a thermal only or coupled structural thermal analysis Also CONTROL_SOLUTION CONTROL_THERMAL_SOLVER needed Card Format 1 2 3 4 5 6 7 8 me fete tet tet ete VARIABLE DESCRIPTION TS Time step control EQ 0 fixed time step EQ 1 variable time step may increase or decrease TIP Time integration parameter EQ 0 0 set to 0 5 Crank Nicholson scheme EQ 1 0 fully implicit ITS Initial thermal time step TMIN Minimum thermal time step EQ 0 0 set to structural explicit timestep TMAX Maximum thermal time step EQ 0 0 set to 100 structural explicit timestep DTEMP Maximum temperature change in each time step above which the thermal timestep will be decreased EQ 0 0 set to a temperature change of
485. olid elements ranged from a one point quadrature eight noded element with hourglass control to a twenty noded element with eight integration points Due to the high cost of the twenty node solid the zero energy modes related to the reduced 8 point integration and the high frequency content which drove the time step size down higher order elements were all but abandoned in later versions of DYNA3D A two dimensional version DYNA2D was developed concurrently A new version of DYNA3D was released in 1979 that was programmed to provide near optimal speed on the CRAY 1 supercomputers contained an improved sliding interface treatment that permitted triangular segments and was an order of magnitude faster than the previous contact treatment The 1979 version eliminated structural and higher order solid elements and some of the material models of the first version This version also included an optional element wise implementation of the integral difference method developed by Wilkins et al 1974 The 1981 version Hallquist 1981a evolved from the 1979 version Nine additional material models were added to allow a much broader range of problems to be modeled including explosive structure and soil structure interactions Body force loads were implemented for angular velocities and base accelerations A link was also established from the 3D Eulerian code JOY Couch et al 1983 for studying the structural response to impacts by penetrating projectiles A
486. om the equation solver 0 Diagnostic information is off default EQ 1 Diagnostic information is on Activate the generation of a convergence history file from the equation solver EQ 0 Convergence history is off default EQ 1 Convergence history is on Set the convergence criteria for the iterative equation solver EQ 0 EPS 1 0e 5 default Set the type of hourglass stabilization to be used with the momentum equations This only applies to the explicit treatment of the momentum equations INSOL 1 EQ 0 IHG 1 default EQ 1 LS DYNA viscous hourglass stabilization EQ 2 y hourglass stabilization viscous form Set the hourglass stabilization multiplier see IHG above EQ 0 EHG 1 0 default 1 IMASS variable is only active when INSOL22 on the CONTROL_CFD_GENERAL keyword 2 The balancing tensor diffusivity should always be used with explicit treatment of the advection terms This is the default 3 The use of flux limiting procedures is currently restricted to the explicit advective procedures 7 24 CONTROL LS DYNA Version 960 CONTROL 4 time weighting variables only apply to the case when INSOL22 on the CONTROL_CFD_GENERAL keyword 5 ITSOL keyword for the CONTROL CFD TRANSPORT keyword only applies for INSOL 22 on the CONTROL CFD GENERAL keyword LS DYNA Version 960 7 25 CONTROL CONTROL CONTROL CFD TURBULENCE Purpose Activate a turbulence model
487. on 960 AIRBAG AIRBAG Purpose Define an airbag or control volume The keyword AIRBAG provides a way of defining thermodynamic behavior of the gas flow into the airbag as well as a reference configuration for the fully inflated bag The keyword control cards in this section are defined in alphabetical order AIRBAG_OPTIONI_ OPTION2 _ OPTION3 _ lt OPTIONAL NUMERIC ID AIRBAG_INTERACTION AIRBAG REFERENCE GEOMETRY OPTION OPTION AIRBAG OPTIONI_ OPTION2 specifies one of the following thermodynamic relationships SIMPLE PRESSURE VOLUME SIMPLE AIRBAG MODEL ADIABATIC GAS MODEL WANG NEFSKE WANG NEFSKE JETTING WANG NEFSKE MULTIPLE JETTING LOAD CURVE LINEAR FLUID HYBRID HYBRID JETTING HYBRID CHEMKIN OPTION2 specifies that an additional line of data is read for the WANG NEFSKE type thermodynamic relationships The additional data controls the initiation of exit flow from the airbag OPTION takes the single option POP OPTIONS specifies that a constant momentum formulation is used to calculate the jetting load on the airbag an additional line of data is read in OPTIONS takes the single option CM The OPTIONAL NUMERIC ID is a unique number used only for identification of the airbag in the definition of airbag interaction via AIRBAG INTERACTION The numeric ID is not used for any other purpose To define an airbag using the Wang Nefske thermodynamic relationship with an ID of 25 the keyword is AIRBAG W
488. on and stop angles for y rotation See Figure 5 16 If zero friction and stop angles are inactive for y rotation FMPS Frictional moment limiting value for y rotation If zero friction is inactive for y rotation This option may also be thought of as an elastic plastic spring If a negative value is input then the absolute value is taken as the load curve ID defining the yield moment versus y rotation See Figure 5 16 5 36 CONSTRAINED LS DYNA Version 960 CONSTRAINED Card 4 of 4 Required for GENERALIZED stiffness Card 4 1 2 3 4 5 6 NSAPH PSAPH NSAT PSAT NSAPS PSAPS aa w fet ef ef et ete VARIABLE DESCRIPTION NSAPH Stop angle in degrees for negative 6 rotation Ignored if zero PSAPH Stop angle in degrees for positive 6 rotation Ignored if zero NSAT Stop angle in degrees for negative rotation Ignored if zero PSAT Stop angle in degrees for positive rotation Ignored if zero NSAPS Stop angle in degrees for negative y rotation Ignored if zero PSAPS Stop angle in degrees for positive y rotation Ignored if zero Remarks After the stop angles are reached the torques increase linearly to resist further angular motion using the stiffness values on Card 3 Reasonable stiffness values have to be chosen If the stiffness values are too low or zero the stop will be violated LS DYNA Version 960 5 37 CONSTRAINED CONSTRAINED Figure 5 15 Definition of angles for the generalized joint stiffness The magni
489. on is required with the absolute value of the parameter SCOOR set to 2 or 3 since this option avoids rotational constraints EQ 0 the spring damper acts along the axis from node N1 to N2 0 the spring damper acts along the axis defined by the orientation vector VID defined in the DEFINE SD ORIENTATION section S Scale factor on forces PF Print flag EQ 0 forces are printed in DEFORC file see DATABASE OPTION EQ 1 forces are not printed DEFORC file OFFSET Initial offset The initial offset is a displacement or rotation at time zero For example a positive offset on a translational spring will lead to a tensile force being developed at time zero 12 10 ELEMENT LS DYNA Version 960 ELEMENT ELEMENT_INERTIA Purpose Define a lumped inertia element assigned to a nodal point Card Format 1018 Card Format 8110 SIE VARIABLE DESCRIPTION EID Element ID A unique number must be used NID Node ID Node to which the mass is assigned CSID Coordinate set ID EQ 0 global inertia tensor GE 1 principal moments of inertias with orientation vectors defined by Coordinate set CSID See DEFINE_COORDINATE_SYSTEM and DEFINE_COORDINATE_VECTOR LS DYNA Version 960 12 11 ELEMENT ELEMENT VARIABLE DESCRIPTION IXx XX component of inertia tensor IXY XY component of inertia tensor IXZ XZ component of inertia tensor IYY YY component of inertia tensor IYZ YZ component of inertia tensor 177 ZZ comp
490. on of time Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION XJFP x coordinate of jet focal point 1 e the virtual origin in Figure 1 1 See Remark 1 below YJFP y coordinate of jet focal point i e the virtual origin in Figure 1 1 ZJFP z coordinate of jet focal point 1 the virtual origin in Figure 1 1 XJVH x coordinate of jet vector head to defined code centerline 1 32 AIRBAG LS DYNA Version 960 AIRBAG VARIABLE DESCRIPTION YJVH y coordinate of jet vector head to defined code centerline ZJVH z coordinate of jet vector head to defined code centerline CA Cone angle defined in radians LT 0 0 lal is the load curve ID defining cone angle as a function of time BETA Efficiency factor B which scales the final value of pressure obtained from Bernoulli s equation LT 0 0 IBI is the load curve ID defining the efficiency factor as a function of time XSJFP x coordinate of secondary jet focal point passenger side bag If the coordinate of the secondary point is 0 0 0 then a conical jet driver s side airbag is assumed YSJFP y coordinate of secondary jet focal point ZSJFP z coordinate of secondary jet focal point PSID Optional part set ID see SET PART If zero all elements are included in the airbag IDUM Dummy field Variable not used NODEI Node ID located at the jet focal point i e the virtual origin in Figure 1 1 See Remark 1 below NODE2 Node ID for node alo
491. onal cards are defined for the WANG_NEFSKE_JETTING and WANG_NEFSKE_MULTIPLE_JETTING options two further cards are defined for each option The jet may be defined by specifying either the coordinates of the jet focal point jet vector head and secondary jet focal point or by specifying three nodes located at these positions The nodal point option is recommended when the location of the airbag changes as a function of time Define either card below but not both 1st additional card of 2 required for WANG_NEFSKE_JETTING option Card 1 1 2 3 4 5 6 7 8 L LEM lst additional card of 2 required for WANG NEFSKE MULTIPLE JETTING option Card 1 1 2 3 4 5 6 7 8 fe fe Pe fpf LS DYNA Version 960 1 19 AIRBAG AIRBAG 2nd additional card of 2 required for WANG_NEFSKE_JETTING and WANG_NEFSKE_MULTIPLE_JETTING option Card 2 1 2 3 4 5 6 7 8 XSJFP YSJFP ZSJFP PSID ANGLE NODEI NODE2 NODE3 VARIABLE DESCRIPTION XJFP x coordinate of jet focal point i e the virtual origin in Figure 1 1 See Remark 1 below YJFP y coordinate of jet focal point i e the virtual origin in Figure 1 1 ZJFP z coordinate of jet focal point i e the virtual origin in Figure 1 1 XJVH x coordinate of jet vector head to defined code centerline YJVH y coordinate of jet vector head to defined code centerline ZJVH z coordinate of jet vector head to defined code centerline CA Cone angle defined in radians LT 0 0 lol is the load curve ID defi
492. onal part set ID of rigid bodies that are slaved in the minimum coordinate direction to the master rigid body This option requires additional input by the SET PART definition Load curve ID which defines the maximum absolute value of the velocity that is allowed within the stopper EQ 0 no limitation of the minimum displacement Direction stopper acts in EQ 1 x translation EQ 2 y translation EQ 3 z translation EQ 4 arbitrary defined by vector VID EQ 5 x axis rotation EQ 6 y axis rotation EQ 7 z axis rotation EQ 8 arbitrary defined by vector VID Vector for arbitrary orientation of stopper The vector must be defined by a DEFINE_VECTOR within the present restart deck Time at which stopper is activated Time at which stopper is deactivated The optional definition of part sets in minimum or maximum coordinate directions allows the motion to be controlled in an arbitrary direction 29 8 RESTART LS DYNA Version 960 RESTART The STATUS REPORT FREQUENCY option allows the output status interval to be changed Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IKEDIT Problem status report interval steps in the D3HSP output file 0 interval remains unchanged LS DYNA Version 960 29 9 RESTART RESTART The THERMAL PARAMETERS option allows parameters used by a thermal or coupled structural thermal analysis to be changed These parameters were initially defined on the CONTROL THERMAL
493. onation point L the detonation velocity D and the lighting time for the detonator t L t t D The detonation velocity for this default option is taken from the element whose lighting time is computed and does not account for the possiblities that the detonation wave may travel through other explosives with different detonation velocities or that the line of sight may pass outside of the explosive material If the control card option CONTROL_EXPLOSIVE_SHADOW is defined the lighting time is based on the shortest distance through the explosive material If inert obstacles exist within the explosive material the lighting time will account for the extra time required for the detonation wave to travel around the obstacles The lighting times also automatically accounts for variations in the detonation velocity if different explosives are used No additional input is required for this option but care must be taken when setting up the input This option works for two and three dimensional solid elements It is recommended that for best results l Keep the explosive mesh as uniform as possible with elements of roughly the same dimensions 2 Inert obstacle such as wave shapers within the explosive must be somewhat larger than the characteristic element dimension for the automatic tracking to function properly Generally a factor of two should suffice The characteristic element dimension is found by checking all explosive elements for
494. onent of inertia tensor Remarks 1 coordinate system cannot be defined using the option DEFINE COORDINATE NODE for this element 2 If CSID is defined then IXY IXZ and IYZ are set to zero The nodal inertia tensor must be positive definite i e its determinant must be greater than zero since its inverse is required This check is done after the nodal inertia is added to the defined inertia tensor 12 12 ELEMENT LS DYNA Version 960 ELEMENT ELEMENT_MASS Purpose Define a lumped mass element assigned to a nodal point Card Format 218 E16 0 1 2 3 4 5 6 7 8 9 10 1111 EEE VARIABLE DESCRIPTION EID Element ID A unique number must be used NID Node ID Node to which the mass is assigned MASS Mass value LS DYNA Version 960 12 13 ELEMENT ELEMENT ELEMENT_SEATBELT Purpose Define a seat belt element Card Format 518 16 0 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION EID Element ID A unique number has to be used PID Part ID NI Node 1 ID N2 Node 2 ID SBRID Retractor ID see ELEMENT SEATBELT RETRACTOR SLEN Initial slack length Remarks l The retractor ID should be defined only if the element is initially inside a retractor see ELEMENT SEATBELT RETRACTOR 2 Belt elements are single degree of freedom elements connecting two nodes When the strain in an element is positive i e the current length is greater then
495. ons exist If neighbor 2 j is set to zero then a linear computation of the gradient in the side 2 to side 4 direction will be made using the difference between the doublet strengths on segment j and segment neighbor 4 j This is the default setup used by LS DYNA when no user input is provided By specifying neighbor 2 j as a negative number a more accurate quadratic curve fit will be used to compute the gradient The curve fit will use segment j segment neighbor 4 j and segment neighbor 2 j which is located on the opposite side of segment neighbor 4 j as segment j 3 14 BOUNDARY LS DYNA Version 960 BOUNDARY neighbor 2 j segment j side 2 neighbor 4 j Figure 3 4 If neighbor 2 j is a negative number it is assumed to lie on the opposite side of neighbor 4 j as segment j Another possibility is that no neighbors at all are available in the side 2 to side 4 direction In this case both neighbor 2 j and neighbor 4 j can be set to zero and the gradient in that direction will be assumed to be zero This option should be used with caution as the resulting fluid pressures will not be accurate for three dimensional flows However this option is occaisionally useful where quasi two dimensional results are desired All of the above options apply to the side 1 to side 3 direction in the obvious ways For triangular boundary elements side 4 is null Gradients in the side 2 to side 4 direction can be computed as desc
496. ooth surfaces artificial friction introduced by standard faceted meshes with corners and edges can be avoided This is a big advantage in springback calculations A very simple and general handling of VDA surfaces is possible allowing arbitrary motion and generation of surfaces For a detailed description see Appendix I MESH GENERATION LS DYNA is designed to operate with a variety of commercial pre processing packages Currently direct support is available from TRUEGRID PATRAN FEMB HYPERMESH and MEDINA Several third party translation programs are available for PATRAN and IDEAS Alternately the pre processor LS INGRID LSTC Report 1019 is available from LSTC and is specialized to LS DYNA Some of the capabilities available in LS INGRID are Complete support for all control parameters loads and material types l TRUEGRID is a trademark of XYZ Scientific Applications Inc PATRAN is a trademark of PDA Engineering HYPERMESH is a trademark of Altair Engineering FEMB is a trademark of Engineering Technology Associates IDEAS is a trademark of Structural Dynamics Research Corporation 1 32 INTRODUCTION LS DYNA Version 960 INTRODUCTION Mass property calculations Importing models from other sources TRUEGRID PATRAN IDEAS IGES and NASTRAN formats Interactive viewing and graphical inspection of boundary conditions etc Model editing General purpose mesh generation Importing LS DYNA and DYNA3D models in a variety of
497. option is used all mass and inertia properties of the body must be specified for there are no default values Note that the off diagonal terms of the inertia tensor are opposite in sign from the products of inertia LS DYNA Version 960 21 9 PART PART PART_MODES Purpose Define mode shapes for a flexible rigid body Currently flexible bodies cannot be merged into other flexible bodies or rigid bodies however interconnections to other rigid flexible bodies can use the penalty joint option The flexible rigid bodies are not implemented with the Lagrange multiplier joint option The deformations are modeled using the modes shapes obtained experimentally or in a finite element analysis e g NASTRAN pch file or an LSTC eigout file These modes should include both constraint and attachment modes For stress recovery in flexible rigid bodies use of linear element formulations is recommeded A lump mass matrix is assumed in the implementation Also see the keyword control card CONTROL_RIGID Card Format Card 1 ze FORM ANSID FORMAT KMFLAG NUPDF SIGREC EHEN EN EN EN EN EN EN Card 2 Define the following cards if and only if KMFLAG 1 Use as many cards as necessary to identify the NMFB kept modes After NMFB modes are defined no further input is expected Cards 3 MODEI MODE2 MODE3 MODE4 MODES MODE6 MODE7 MODES 21 10 PART LS DYNA Version 960 PART ngn Read optional modal damping cards
498. orkers Belytschko and Marchertas 1974 Bazeley et al 1965 Belytschko et al 1984 and are 1 22 INTRODUCTION LS DYNA Version 960 INTRODUCTION frequently used since collapsed quadrilateral shell elements tend to lock and give very bad results LS DYNA automatically treats collapsed quadrilateral shell elements as triangular elements Since the Belytschko Tsay element is based on a perfectly flat geometry warpage is not considered Although this generally poses no major difficulties and provides for an efficient element incorrect results in the twisted beam problem and similar situations are obtained where the nodal points of the elements used in the discretization are not coplanar The Hughes Liu shell element considers non planar geometries and gives good results on the twisted beam The effect of neglecting warpage in a typical application cannot be predicted beforehand and may lead to less than accurate results but the latter is only speculation and is difficult to verify in practice Obviously it would be better to use shells that consider warpage if the added costs are reasonable and if this unknown effect is eliminated Another shell published by Belytschko Wong and Chiang Belytschko Wong and Chiang 1989 1992 proposes inexpensive modifications to include the warping stiffness in the Belytschko Tsay shell An improved transverse shear treatment also allows the element to pass the Kirchhoff patch test This element is now availabl
499. orresponding keyword command for a description 5 DEFINE COORDINATE VECTOR nn Dir EZ De Be DD RAS AO eS oue 5 cid Xx Yx 2 Yv Zv 4 1 0 1 0 0 0 220 7 50 1 0 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 10 31 DEFINE DEFINE 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 DEFINE CURVE 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Define curve number 517 This particular curve is used to define the 5 force deflection properties of a spring defined by MAT SPRING INELASTIC 5 keyword The abscissa value is offset 25 0 as a means of modeling a gap 6 at the front of the spring This type of spring would be a compression 6 only spring DEFINE CURVE Zn BD De WES saad Ocho aua edel 5 lcid sidr scla sclo offa offo 517 25 0 5 abscissa ordinate 0 0 0 0 80 0 58 0 95 0 35 0 150 0 44 5 350 0 45 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 955 DEFINE SD ORIENTATION 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 A discrete spring is defined with two nodes in 3 D space However it is desired to have the force of that spring to act only in the z direction T
500. osen for the family member is the n th restart file from the last run where the data is taken LS DYNA automatically detects that a small input deck is used since the I restartinput file may contain the keywords CHANGE_OPTION CONTROL_DYNAMIC_RELAXATION CONTROL_TERMINATION CONTROL_TIMESTEP LS DYNA Version 960 29 1 RESTART RESTART 29 2 RESTART DAMPING GLOBAL DATABASE_OPTION DATABASE BINARY OPTION DELETE OPTION INTERFACE SPRINGBACK RIGID DEFORMABLE OPTION STRESS_INITIALIZATION_ OPTION TERMINATION_OPTION TITLE KEYWORD see INTRODUCTION Execution Syntax CONTROL_CPU DEFINE_OPTION SET_OPTION i e the keyword STRESS INITIALIZATION may not be used in the small restart The user has to take care that nonphysical modifications to the input deck are avoided otherwise complete nonsense may be the result If many modifications are desired a so called full restart may be the appropriate choice Then the keyword STRESS INITIALIZATION has to be provided in the input As also outlined in the INTRODUCTION Restart Analysis either all parts can be initialized with the restart data or some selection of parts can be made for the stress initialization See STRESS INITIALIZATION In a full deck restart deleted elements in this section will be deleted in the full deck automatically even though they are defined Likewise if it is necessary to change the velocity field that must also be performed in this
501. ot the nodes are projected back to the contact surface during the initialization phase The OFFSET option switches the formulation from a constraint type formulation to one that is penalty based Remarks 1 OPTION2 OPTIONS and OPTION4 may appear in any order in the keyword command line The data must be in the order specified below 2 OPTIONI is mandatory 3 OPTION2 OPTIONS and OPTION4 are optional 4 The following contact types are available for implicit calculations SURFACE TO SURFACE NODES TO SURFACE LS DYNA Version 960 6 3 CONTACT CONTACT 6 4 CONTACT ONE_WAY_SURFACE_TO_SURFACE FORMING_SURFACE_TO_SURFACE FORMING_NODES_TO_SURFACE FORMING ONE WAY SURFACE TO SURFACE AUTOMATIC SURFACE TO SURFACE AUTOMATIC NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE TIED SURFACE TO SURFACE OFFSET TIED NODES TO SURFACE OFFSET 2D AUTOMATIC SURFACE TO SURFACE LS DYNA Version 960 CONTACT DISCUSSION AND EXAMPLES A brief discussion on the contact types and a few examples are provided at the end of this section A theoretical discussion is provided in the LS DYNA Theory Manual Card_ordering is important in this section e Card for the TITLE option is inserted here otherwise do not define this card Define the title card first Cards 1 to 3 are mandatory for all contact types Card 4 is mandatory for the following contact types CONTACT_CONSTRAINT_type CONTACT
502. otion value versus time see DEFINE_ CURVE SF Load curve scale factor default 1 0 3 32 BOUNDARY LS DYNA Version 960 BOUNDARY VARIABLE DESCRIPTION VID Vector ID for DOF values of 4 or 8 see DEFINE VECTOR DEATH Time imposed motion constraint is removed EQ 0 0 default set to 1028 BIRTH Time imposed motion constraint is activated OFFSETI Offset for DOF types 9 11 y z x direction OFFSET2 Offset for DOF types 9 11 z x y direction MRB Master rigid body for measuring the relative displacement NODEI Optional orientation node nl for relative displacement NODE2 Optional orientation node n2 for relative displacement Remarks Arbitrary translations and rotations are possible Rotations around local axis can be defined either by setting DOF 8 or by using the offset option of DOF gt 8 The load curve scale factor can be used for simple modifications or unit adjustments The relative displacement can be measured in either of two ways 1 Along a straight line between the mass centers of the rigid bodies 2 Along a vector beginning at node n1 and terminating at node n2 With option 1 a positive displacement will move the rigid bodies further apart and likewise a negative motion will move the rigid bodies closer together The mass centers of the rigid bodies must not be coincident when this option is used With option 2 the relative displacement is measured along the vector and the rigid bodies may be coincident
503. ourglass control from version 936 was to ensure that all components of the hourglass force vector are orthogonal to rigid body rotations However problems that run under version 936 sometimes lead to different results in versions 940 and later This difference in results is primarily due to the modifications in the hourglass force vector Versions released after 936 should be more accurate Purpose Set the default values of the hourglass control to override the default values Card Format 1 2 3 4 5 6 7 8 oto DE em feted VARIABLE DESCRIPTION IHQ Default hourglass viscosity type EQ 1 standard LS DYNA EQ 2 Flanagan Belytschko integration EQ 3 Flanagan Belytschko with exact volume integration EQ 4 stiffness form of type 2 Flanagan Belytschko EQ 5 stiffness form of type 3 Flanagan Belytschko EQ 6 Belytschko Bindeman 1993 assumed strain co rotational stiffness form for 2D and 3D solid elements only This form is available for explicit and IMPLICIT solution methods In fact type 6 is mandatory for the implicit options EQ 8 Applicable to the type 16 fully integrated shell element 8 activates warping stiffness for accurate solutions A speed penalty of 25 is common for this option LS DYNA Version 960 7 41 CONTROL CONTROL VARIABLE DESCRIPTION In the shell elements IHQ lt 4 is the viscous form based on Belytschko Tsay If IHQ
504. ower than previously In general in light of these problems the drill projection cannot be recommended 7 70 CONTROL LS DYNA Version 960 CONTROL CONTROL_SOLID Purpose Provide controls for solid element response Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION ESORT Automatic sorting of tetrahedron and pentahedron elements to treat degenerate hexahedron elements as tetrahedron and pentahedron solids respective See option THEORY below 0 no sorting required default EQ 1 full sorting LS DYNA Version 960 7 71 CONTROL CONTROL CONTROL_SOLUTION Purpose To specify the analysis solution procedure if thermal only or coupled thermal analysis is performed Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SOLN Analysis solution procedure 0 Structural analysis only Thermal analysis only 2 Coupled structural thermal analysis 4 Incompressible low Mach CFD analysis only 5 Coupled incompressible fluid structure interaction Not currently used 7 72 CONTROL LS DYNA Version 960 CONTROL CONTROL_SPH Purpose Provide controls for computing SPH particles Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NCBS Number of cycles between particle sorting BOXID SPH approximations are computed inside a specified BOX When a particle has gone outside the BOX it is deactivated This will save computational time by eliminating particles that no longer interact with th
505. ows control to be passed directly to the automatic time step controller when negative eigenvalues are detected Otherwise significant numerical roundoff error is likely to occur during factorization and equilibrium iterations may fail ORDER The system of linear equations must be reordered to preserve the sparsity of the factorization when using direct methods The older sparse solvers LSOLVR 1 and LSOLVR 3 can only use the Multiple Minimum Degree ordering method The newer sparse direct solvers LSOLVR 4 5 and 6 can use either MMD or Metis Metis is a ordering method from University of Minnesota and is very effective for larger problems and for 3D solid problems MMD is best for smaller problems that is less than 100 000 rows in the assembled stiffness matrix Note that the values of LPRINT and ORDER also affect the eigensolution software That is LPRINT and ORDER from tthis keyword card is applicable to eigensolution LS DYNA Version 960 7 57 CONTROL CONTROL CONTROL_IMPLICIT_STABILIZATION Purpose Define parameters for artificial stabilization during multi step implicit springback analysis Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION IAS Artificial Stabilization flag EQ 1 active Default for springback implicit analysis EQ 2 inactive Default for standard implicit analysis SCALE Scale factor for artificial stabilization Values greater than 1 0 cause less springback in the first few steps
506. phabetically organized in logical sections of input data Each logical section relates to a particular input There is a control section for resetting LS DYNA defaults a material section for defining constitutive constants an equation of state section an element section where element part identifiers and nodal connectivities are defined a section for defining parts and so on Nearly all model data can be input in block form For example consider the following where two nodal points with their respective coordinates and shell elements with their part identity and nodal connectivities are defined DEFINE TWO NODES NODE 10101 x y 7 10201 X y 7 DEFINE TWO SHELL ELEMENTS ELEMENT_SHELL 10201 pid nl n2 n3 n4 10301 pid nol n2 n3 n4 Alternatively acceptable input could also be of the form DEFINE ONE NODE NODE 10101 X y 7 DEFINE ONE SHELL ELEMENT ELEMENT_SHELL 10201 pid nl n2 n3 n4 DEFINE ONE MORE NODE NODE 10201 X y 7 DEFINE ONE MORE SHELL ELEMENT ELEMENT_SHELL 10301 pid nl n2 n3 n4 A data block begins with a keyword followed by the data pertaining to the keyword The next keyword encountered during the reading of the block data defines the end of the block and the beginning of a new block A keyword must be left justified with the contained in column one A 1 12 INTRODUCTION LS DYNA Version 960 INTRODUCTION dollar sign in column one precedes a commen
507. phase with a negative volume message The input of nodes on the element cards for the tetrahedron and pentahedron elements is given by 4 noded tetrahedron N1 2 3 N4 4 4 4 4 6 noded pentahedron N1 N2 3 N4 5 N5 N6 6 If hexahedrons are mixed with tetrahedrons pentahedrons the input under the same part ID degenerate tetrahedrons and pentahedrons are used One problem with degenerate elements is related to an uneven mass distribution node 4 of the tetrahedron has five times the mass of nodes 1 3 which can make these elements somewhat unstable with the default time step size By using the control flag under the keyword CONTROL_SOLID automatic sorting can be invoked to treat the degenerate elements as type 10 and type 15 tetrahedrons and pentahedrons elements respectively For the orthotropic and anisotropic material models the local directions may be defined on the second card following the element connectivity definition The local directions are then computed from the two vectors such that see Figure 12 9 OIL These vectors are internally normalized within LS DYNA Stress output for solid elements is in the global coordinate system by default If vector d is input as a zero length vector then Al is interpreted as a rotation angle in degrees which is used for AOPT 3 on various orthotropic material cards such as MAT OPTION TROPIC ELASTIC 12 36 ELEMENT LS DYNA Version 960 ELEMENT N
508. pose Provide controls for computing shell response Card Format 1 2 3 4 5 6 7 8 Optional 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION WRPANG Shell element warpage angle in degrees If a warpage greater than this angle is found a warning message is printed Default is 20 degrees ESORT Automatic sorting of triangular shell elements to treat degenerate quadrilateral shell elements as CO triangular shells see option THEORY below 0 no sorting required default EQ 1 full sorting IRNXX Shell normal update option This option affects the Hughes Liu Belytschko Wong Chiang and the Belytschko Tsay shell formultions The latter is affected if and only if the warping stiffness option is active i e BWC 1 IRNXX must be set to 2 to invoke the top or bottom surface as the reference surface for the Hughes Liu shell elements EQ 2 unique nodal fibers which are incrementally updated based on the nodal rotation at the location of the fiber EQ 1 recompute fiber directions each cycle LS DYNA Version 960 7 67 CONTROL CONTROL VARIABLE DESCRIPTION EQ 0 default set to 1 EQ 1 compute on restarts EQ n compute every n cycles Hughes Liu shells only ISTUPD Shell thickness change option This option affects all shell element formulations EQ 0 no change EQ 1 membrane straining causes thickness change This option is very important in sheet metal forming or whenever membrane stretchi
509. problem occurs A few of the known problems include 32 bit computers only e Round off errors can cause difficulties with extremely small deflection problems Maximum vibration amplitudes are 10 6 times nodal coordinates Workaround Increase the load e Buckling problems which are very sensitive to small imperfections However the users of LS DYNA have to be aware of potential problems A major reorganization of LS DYNA has led to a version using double precision throughout the full program As memory and disk space of the computers is less of a problem we prefer to provide this version for all machines It also allows LS DYNA to take advantage of the 64 bit technology offered by some computer manufacturers EXECUTION SYNTAX The interactive execution line for LS DYNA is as follows LS DYNA I inf O otf G ptf D dpf F thf U xtf T tpf A rrd Mssif J jif S iff Z isfl L isf2 B rlf W root E efl X scl C cpu K kill V vda Y c3d KEYWORD THERMAL COUPLE INIT MEMORY nwds NCPU ncpu PARA para ENDTIME time NCYLCE ncycle where inf input file user specified otf high speed printer file defaultZD3HSP ptf binary plot file for graphics defaultZD3PLOT LS DYNA Version 960 1 27 INTRODUCTION INTRODUCTION dpf dump file for restarting default D3DUMP This file is written at the end of every run and during the run as requested in the input To stop the generation of this file set the file name to NODUMP thf binary plot fi
510. product pressures and temperatures are assumed to be equilibrated Tp T p Py Pp and the relative volumes are additive V 1 F V F V LS DYNA Version 960 13 25 EOS EOS where V is the total relative volume Other mixture assumptions can and have been used in different versions of DYNA2D 3D The reaction rate law has the form T GROW I P FREQ EM FMXIG ARI 1 F FMXIG ESI t GROW2 P FREQ EN F FMXIG AR2 1 F FMXIG ES2 If F exceeds FMXGR the GROW term is set equal to zero and if F is less than FMNGR GROW2 term is zero Thus two separate or overlapping burn rates can be used to describe the rate at which the propellant decomposes This equation of state subroutine is used together with a material model to describe the propellant In the airbag propellant case a null material model type 10 can be used Material type 10 is usually used for a solid propellant or explosive when the shear modulus and yield strength are defined The propellant material is defined by the material model and the unreacted equation of state until the reaction begins The calculated mixture states are used until the reaction is complete and then the reaction product equation of state is used The heat of reaction ENQ is assumed to be a constant and the same at all values of F but more complex energy release laws could be implemented 13 26 EOS LS DYNA Version 960 EOS EOS_TENSOR_PORE_COLLAPSE This is E
511. ption see AIRBAG or CONSTRAINED _RIGID_BODY_STOPPERS Card Format 1 2 3 4 5 6 7 8 Card 2 3 4 OPTION LIST The next card terminates the input 1 2 3 4 5 6 7 8 PID1 PID2 PID3 PID4 PID5 PID6 PID7 PID8 24 12 SET LS DYNA Version 960 SET Card 2 3 4 OPTION COLUMN The next card terminates the input 1 2 3 4 5 6 7 8 ep Cards 2 3 4 OPTION LIST_GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIEND B2BEG B2END B3BEG B3END B4BEG B4END VARIABLE DESCRIPTION SID Set ID All part sets should have a unique set ID DAI First attribute default value see remark 1 below DA2 Second attribute default value DA3 Third attribute default value DA4 Fourth attribute default value PID Part ID PIDI First part ID PID2 Second part ID Al First part attribute see remark 2 below A2 Second part attribute A3 Third part attribute LS DYNA Version 960 24 13 SET SET VARIABLE 4 BNBEG BNEND Remarks DESCRIPTION Fourth part attribute First part ID in block N Last part ID in block n All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all input is read so that gaps in the part numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not part ID s Part attributes
512. put deck can be generated containing the coarsened mesh 2 By default an automatic search is performed to identify elements for coarsening In some meshes isolated regions of refinement may be overlooked Seed nodes can be identified in these regions to assist the automatic search Seed nodes identify the central node of a four element group which is coarsened into a single element if the angle criterion is satisfied 3 keyword DEFINE BOX COARSEN can be used to indicate regions of the mesh which are protected from coarsening 7 28 CONTROL LS DYNA Version 960 CONTROL CONTROL_CONTACT Purpose Change defaults for computation with contact surfaces Card Format Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 Card 3 is optional The following parameters are the default values used by parts in automatic contacts These frictional coefficients apply only to contact types SINGLE_SURFACE AUTOMATIC_GENERAL AUTOMATIC_SINGLE_ SURFACE AUTOMATIC NODES TO AUTOMATIC SURFACE and AUTOMATIC ONE WAY ERODING SINGLE SURFACE Also see CONTACT and PART Card 3 1 2 3 4 5 6 7 8 w fe fe fe fefefe LS DYNA Version 960 7 29 CONTROL CONTROL Card 4 is optional If this card is defined then Card 3 above must be included A blank card may be inserted for Card 3 Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SLSFAC Scale factor for sliding
513. quation of state Form 11 Card Format Card 1 1 2 3 4 5 6 7 8 w fof e fet ete fe fe Repeat Cards 2 etc as required for ECC and VARIABLE DESCRIPTION EOSID Equation of state label NLD Virgin loading load curve ID NCR Completely crushed load curve ID MUI Excess Compression required before any pores can collapse MU2 Excess Compression point where the Virgin Loading Curve and the Completely Crushed Curve intersect IEO Initial Internal Energy ECO Initial Excess Compression Remarks The pore collapse model described in the TENSOR manual 23 is no longer valid and has been replaced by a much simpler method This is due in part to the lack of experimental data required for the more complex model It is desired to have a close approximation of the TENSOR model in the DYNA code to enable a quality link between them The TENSOR model defines two curves the virgin loading curve and the completely crushed curve as shown in Figure 13 2 It also defines the excess compression point required for pore collapse to begin u1 and the excess compression point required to completely crush the material u2 From this data and the maximum excess compression the material has attained Umax the pressure for any excess compression u can be determined LS DYNA Version 960 13 27 EOS EOS 1 0 Virgin loading curve Completely crushed curve Partially crushed curve 0 04 08 12 16 u 20 2 Excess
514. r LCIDDR Load curve ID for dynamic relaxation phase optional This is only needed if dynamic relaxation is defined and a different load curve to LCID is required during the dynamic relaxation phase Note if LCID is set to zero then no body load will be applied during dynamic relaxation regardless of the value LCIDDR is set to See CONTROL DYNAMIC RELAXATION XC X center of rotation define for angular velocities YC Y center of rotation define for angular velocities ZC Z center of rotation define for angular velocities PSID Part set ID Remarks 1 Translational base accelerations allow body forces loads to be imposed on a structure Conceptually base acceleration may be thought of as accelerating the coordinate system in the direction specified and thus the inertial loads acting on the model are of opposite sign For example if a cylinder were fixed to the y z plan and extended in the positive x direction then a positive x direction base acceleration would tend to shorten the cylinder i e create forces acting in the negative x direction 2 Base accelerations are frequently used to impose gravitational loads during dynamic relaxation to initialize the stresses and displacements During the analysis in this latter case the body forces loads are held constant to simulate gravitational loads When imposing loads during dynamic relaxation it is recommended that the load curve slowly ramp up to avoid the excitation of a high frequenc
515. r default 995 DRTERM Optional termination time for dynamic relaxation Termination occurs at this time or when convergence is attained default infinity TSSFDR Scale factor for computed time step during dynamic relaxation If zero the value is set to TSSFAC defined on CONTROL_TERMINATION After converging the scale factor is reset to TSSFAC IRELAL Automatic control for dynamic relaxation option based on algorithm of Papadrakakis Papadrakakis 1981 EDTTL Convergence tolerance on automatic control of dynamic relaxation IDRFLG Dynamic relaxation flag for stress initialization 0 not active EQ 1 dynamic relaxation is activated 29 16 RESTART LS DYNA Version 960 RESTART Remarks 1 Ifa dynamic relaxation relaxation analysis is being restarted at a point before convergence was obtained then NRCYCK DRTOL DRFCTR DRTERM and TSSFDR will default to their previous values and IDRFLG will be set to 1 2 If dynamic relaxation is activated after a restart from a normal transient analysis LS DYNA continues the output of data as it would without the dynamic relaxation being active This is unlike the dynamic relaxation phase at the beginning of the calculation when a separate database is not used Only load curves that are flagged for dynamic relaxation are applied after restarting LS DYNA Version 960 29 17 RESTART RESTART CONTROL TERMINATION Purpose Stop the job Card Format 1 2 3 4 5 6 7 8
516. r all parameters in the airbag definition then unity should be input Optional curve for exit flow rate versus gauge pressure Initial relative overpressure gauge in control volume Pop Pressure relative pressure gauge for initiating exit flow Ppop Fabric venting option if nonzero CP23 LCCP23 AP23 and LCAP23 are set to zero EQ 1 Wang Nefske formulas for venting through an orifice are used Blockage is not considered EQ 2 Wang Nefske formulas for venting through an orifice are used Blockage of venting area due to contact is considered EQ 3 Leakage formulas of Graefe Krummheuer and Siejak 1990 are used Blockage is not considered EQ 4 Leakage formulas of Graefe Krummheuer and Siejak 1990 are used Blockage of venting area due to contact is considered EQ 5 Leakage formulas based on flow through a porous media are used Blockage is not considered EQ 6 Leakage formulas based on flow through a porous media are used Blockage of venting area due to contact is considered Optional load curve ID defining the knock down pressure scale factor versus time This option only applies to jetting The scale factor defined by this load curve scales the pressure applied to airbag segments which do not have a clear line of sight to the jet Typically at very early times this scale factor will be less than unity and equal to unity at later times The full pressure is always applied to segments which can see the jets
517. r other imposed motion feature 2 Sensor triggers when the distance between the two nodes is d gt dmax or d Sensors are used to trigger locking of retractors and activate pretensioners Four types of sensors are available which trigger according to the following criteria 12 26 ELEMENT LS DYNA Version 960 ELEMENT Type 1 When the magnitude of x y or z acceleration of a given node has remained above a given level continuously for a given time the sensor triggers This does not work with nodes on rigid bodies Type 2 When the rate of belt payout from a given retractor has remained above a given level continuously for a given time the sensor triggers Type 3 The sensor triggers at a given time Type 4 The sensor triggers when the distance between two nodes exceeds a given maximum or becomes less than a given minimum This type of sensor is intended for use with an explicit mass spring representation of the sensor mechanism By default the sensors are inactive during dynamic relaxation This allows initial tightening of the belt and positioning of the occupant on the seat without locking the retractor or firing any pretensioners However a flag can be set in the sensor input to make the sensors active during the dynamic relaxation phase LS DYNA Version 960 12 27 ELEMENT ELEMENT ELEMENT_SEATBELT_SLIPRING Purpose Define seat belt slip ring Card Format 1 2 3 4 5 6 7 8
518. r two dimensional problems repeat the second node for the third and fourth nodes in the segment definitions LS DYNA Version 960 19 27 LOAD LOAD LOAD_SHELL_OPTION Options include ELEMENT SET Purpose Apply the distributed pressure load over one shell element or shell element set The numbering of the shell nodal connectivities must follow the right hand rule with positive pressure acting in the negative t direction See Figure 19 3 This option applies to the three dimensional shell elements only Card Format Default VARIABLE DESCRIPTION EID ESID Shell ID SID or shell set ID SSID see ELEMENT_SHELL or SET_ SHELL LCID Load curve ID see DEFINE_CURVE SF Load curve scale factor AT Arrival time for pressure or birth time of pressure Remarks 1 If LCID is input as 1 then the Brode function is used to determine the pressure for the segments see also LOAD_BRODE 2 If LCID is input as 2 then the ConWep function is used to determine the pressure for the segments see LOAD_BLAST 3 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled 19 28 LOAD LS DYNA Version 960 LOAD 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LOAD SHELL ELEMENT 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 From a sheet metal forming example A blank is hit b
519. rd must have the option specified See table below OPTION ENTITY define up to 7 FUNCTION ALL EEE All nodes will be included in the set nl n2 n3 n4 n5 n6 n7 Nodes nl n2 n3 will be included nl n2 n3 n4 n5 n6 n7 Nodes n1 n2 n3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Nodes of parts pl p2 p3 will be included bl b2 b3 b4 b5 b6 b7 Nodes inside boxes bl b2 b3 will be included DBOX b1 b2 b3 b4 b5 b6 b7 Nodes inside boxes b1 b2 b3 previously added will be excluded DPART pl p2 p3 p4 p5 p6 p7 Nodes of parts p1 p2 p3 previously added will be excluded 24 10 SET LS DYNA Version 960 SET Remarks 1 Nodal attributes can be assigned for some input types For example for contact option CONTACT TIEBREAK NODES TO SURFACE the attributes are DAI NFLF Normal failure force DA2 NSFLF Shear failure force DA3 NNEN Exponent for normal force DA4 NMES Exponent for shear force 22 The default nodal attributes be overridden on these cards otherwise Al DAl etc LS DYNA Version 960 24 11 SET SET SET_PART_OPTION Available options include LIST COLUMN LIST_GENERATE The last option will generate a block of part ID s between a starting part ID number and an ending part ID number An arbitrary number of blocks can be specified to define the part set Purpose Define a set of parts with optional attributes For the column o
520. re V is the relative volume E is the energy per unit initial volume A B R and o are input constants defined above 13 32 EOS LS DYNA Version 960 EOS JWLB input constants for some common explosives as found in Baker and Stiel 1997 are given in the following table LX 14 PETN Octol 70 30 0 g cc 1 803 EO Mbar 09590 cm us 82994 PCJ Mbar 29369 Al Mbar 526 83 A2 Mbar 60 579 A3 Mbar 91248 A4 Mbar 00159 RI 52 106 R2 8 3998 R3 2 1339 R4 18592 00968 39023 011929 18466 20 029 5 4192 3 2394 LS DYNA Version 960 1 5868 13 33 EOS EOS 13 34 EOS LS DYNA Version 960 HOURGLASS HOURGLASS HOURGLASS Purpose Define hourglass and bulk viscosity properties Using the PART definition this specification is connected to the elements An additional option TITLE may be appended to HOURGLASS keywords If this option is used then an addition line is read for each section in 80a format which can be used to describe the section At present LS DYNA does make use of the title Inclusion of titles gives greater clarity to input decks Card Format Card 1 1 2 3 4 5 6 7 8 EEE EIERN VARIABLE DESCRIPTION HGID Hourglass ID Unique numbers have to be specified THQ Hourglass control typ
521. red to provide a stress versus strain curve for each strain rate n strain rates would be defined following the DEFINE TABLE keyword The curves then follow which make up the table There are no rules for defining the n curves i e each curve may have a different origin spacing and number of points in their definition Load curve ID s defined for the table may be referenced elsewhere in the input This rather awkward input is done for efficiency reasons related to the desire to avoid indirect addressing in the inner loops used in the constitutive model stress evaluation Card Format Card 2 3 4 etc Put one point per card E20 0 Input is terminated when a DEFINE CURVE card is found 1 2 3 4 5 6 7 8 LS DYNA Version 960 10 23 DEFINE DEFINE Insert one DEFINE CURVE input section here for each point defined above VARIABLE DESCRIPTION TBID Table ID Tables and Load curves may not share common ID s LS DYNA3D allows load curve ID s and table ID s to be used interchangeably VALUE Load curve will be defined corresponding to this value e g this value could be a strain rate see purpose above Remark 1 If for example 10 stress strain curves for 10 different strain rates are given 10 cards with the ascending values of strain rate then follow the first card Afterwards 10 corresponding DEFINE_CURVE specifications have to follow 10 24 DEFINE LS DYNA Version 960 DEFINE DEFINE TRANSFORMATION Pu
522. rees of freedom Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 Card 3 1 2 3 4 5 6 7 8 6 52 CONTACT LS DYNA Version 960 VARIABLE CID PSID BOXID SSID FS FD DC LCIDX LCIDY LCIDZ FSLCID FDLCID SFS LS DYNA Version 960 CONTACT DESCRIPTION Contact interface ID This must be a unique number Part set ID of all parts that may contact the rigid surface See SET_PART Include only nodes of the part set that are within the specified box see DEFINE BOX in contact If BOXID is zero all nodes from the part set PSID will be included in the contact Segment set ID defining the rigid surface See SET_SEGMENT Static coefficient of friction The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact FD FS FD e If FSLCID is defined see below then FS is overwritten by the value from the load curve Dynamic coefficient of friction The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact u FD FS FD e If FDLCID is defined see below then FD is overwritten by the value from the load curve Exponential decay coefficient The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact FD FS P Coefficient for viscous friction This is necessary to limit the frict
523. ress for OPTION 2 or 3 below For OPTION 5 NFLS becomes the plastic yield stress See remark below Shear failure stress for OPTION 2 or 3 below Failure criterion 2 2 sq NFLS SFLS For OPTION 5 SFLS becomes the load curve ID of the damage model Critical distance Define for option 6 above After failure this contact option behaves as a surface to surface contact with no thickness offsets After failure no interface tension is possible The soft constraint option with SOFT 2 is not implemented for the tiebreak option LS DYNA Version 960 6 13 CONTACT CONTACT This Card 4 is mandatory for CONTACT_CONSTRAINT_NODES_TO_SURFACE CONTACT_CONSTRAINT_SURFACE_TO_SURFACE Card 4 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION KPF Kinematic partition factor for constraint EQ 0 0 fully symmetric treatment EQ 1 0 one way treatment with slave nodes constrained to master surface Only the slave nodes are checked against contact EQ 1 0 one way treatment with master nodes constrained to slave surface Only the master nodes are checked against contact P3 P2 pi v rel Figure 6 1 Friction coefficient u can be a function of realtive velocity and pressure Specify a flag for the static coefficient of friction FS and a table ID for the dynamic coefficient This option only works with SURFACE TO SURFACE and ONE WAY SURFACE TO SURFACE with thickness offsets 6 14 CONTACT L
524. rian ambient formulation 7 and defined to be pressure outflow ambient elements 3 See SECTION SOLID OPTION For the SET option define the following card Card Format Card 1 1 2 3 4 5 6 7 8 _ I pom fm ft ft For the SEGMENT option define the following card Card Format Card 1 1 2 3 4 5 6 7 8 diu TE d polo LS DYNA Version 960 3 37 BOUNDARY BOUNDARY VARIABLE DESCRIPTION SSID Segment set ID N1 N2 Node ID s defining segment 3 38 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY RADIATION OPTION Available options are SEGMENT SET Purpose Define radiation boundary conditions for a thermal or coupled thermal structural analysis Two cards are defined for each option There are two types of radiation boundary conditions that can be specified 1 The first type models radiation exchange between a finite element surface segment and the environment at temperature The view factor between the finite element surface segment and the environment is 1 2 The second type models the radiation exchange between all the finite element segments that define a completely closed volume The view factors between all the finite element segments defining the enclosure must be calculated and stored in a file named viewfl With the SET option multiple independent boundary radiation enclosures may be defined For the SET option define the following card Card Format
525. ribed above by setting neighbor 4 j to zero for a linear derivative computation this is the default setup used by LS DYNA when no user input is provided or to a negative number to use the segment on the other side of neighbor 2 j and a quadratic curve fit There may also be another triangular segment which can be used as neighbor 4 j see Figure 3 5 neighbor 4 j 1 segment J side 2 Figure 3 5 Sometimes another triangular boundary element segment can be used as neighbor 4 j The rules for computing the doublet gradient in the side 2 to side 4 direction can be summarized as follows the side 1 to side 3 case is similar LS DYNA Version 960 3 15 BOUNDARY BOUNDARY Table 3 1 Surface pressure computation for element quadratic fit using elements j NABOR2 and NABORA LT O quadratic fit using elements j NABOR2 and NABOR4 NABOR2 is assumed to lie on the opposite side of NABOR4 as segment j see Fig 3 4 linear fit using elements j and NABOR4 linear fit using elements j and NABOR2 zero gradient 0 quadratic fit using elements j NABOR2 NABOR4 NABORA is assumed to lie on the opposite side of NABOR2 as segment j 141 IN MM 0 3 16 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY ELEMENT METHOD SYMMETRY Purpose To define a plane of symmetry for the boundary element method The SYMMETRY option can be used to reduce the time and memory required for symmetric
526. rons The type of solid element and its formulation is specified through the part ID see PART and the section ID see SECTION_SOLID_OPTION Also a local coordinate system for orthotropic and anisotropic materials can be defined by using the ORTHO option Card Format 1018 1 2 3 4 5 6 7 8 9 10 Default none none none none none none none none none none Optional Cards Required if ORTHO is specified after the keyword Optional card 1 1 2 3 4 5 6 4 8 9 10 M w foe foe foe Remarks 12 34 ELEMENT LS DYNA Version 960 ELEMENT Optional card 2 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION EID Element ID A unique number has to be chosen PID Part ID see PART NI Nodal point 1 N2 Nodal point 2 N3 Nodal point 3 N8 Nodal point 8 Al x component of local material direction a or else rotation angle in degrees see remark 4 A2 y component of local material direction a A3 z component of local material direction a DI x component of vector in the plane of the material vectors a and b D2 y component of vector in the plane of the material vectors a and b D3 z component of vector in the plane of the material vectors a and b LS DYNA Version 960 12 35 ELEMENT ELEMENT Remarks 1 Four six and eight node elements are depicted in Figure 12 8 where the ordering of the nodal points is shown This ordering must be followed or code termination with occur during the initialization
527. rpose Define a transformation for the INCLUDE TRANSFORM keyword option The DEFINE TRANSFORMATION command must be defined before the INCLUDE TRANSFORM command can be used Card Format Cards 1 2 3 4 The next card terminates the input This set is a combination of a series of options listed in the table defined below Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TRANID Transform ID OPTION For the available options see the table below 1 7 Specified entity Each card must have an option specified See table below for the three available options LS DYNA Version 960 10 25 DEFINE DEFINE FORMAT A10 7F10 0 OPTION ENTITIES ATTRIBUTES FUNCTION SCALE al a2 a3 Scale the x y and z coordinates of a point by al a2 and a3 respectively If zero a default of unity is set ROTATE al a2 a3 a4 a5 a6 a7 Rotate through an angle a7 about a line with direction cosines al a2 and a3 passing through the point a4 a5 and a6 TRANSL al a2 a3 Translate the x y and z coordinates of a point by al a2 and a3 respectively The ordering of the SCALE ROTATE and TRANSL commands is important It is generally recommend to first scale then rotate and finally translate the model The DEFINE TRANSFORMATION command is used 3 times to input the same dummy model and position it as follows 1 Transformation id 1000 imports the dummy model du
528. rsion 960 12 31 ELEMENT ELEMENT 3 Counterclockwise node numbering determines the top surface see Figure 12 5 4 Stresses and strain output in the binary databases are by default given in the global coordinate system Stress resultants are output in the local coordinate system for the shell element 5 Interior angles must be less than 180 degrees 6 To allow for an arbitrary orientation of the shell elements within the finite element mesh each ply in the composite has a unique material orientation angle which measures the offset from some reference in the element Each integration point through the shell thickness typically though not limited to one point per ply requires the definition of the orientation angle at that point The reference is determined by the angle w which can be defined for each element on the element card and is measured from the 1 2 element side Figures 12 6 and 12 7 depict these angles 5 n3 Figure 12 5 LS DYNA shell elements Counterclockwise node numbering determines the top surface 12 32 ELEMENT LS DYNA Version 960 ELEMENT Figure 12 7 A multi layer laminate can be defined The angle is defined for the ith lamina integration point see SECTION_SHELL LS DYNA Version 960 12 33 ELEMENT ELEMENT ELEMENT_SOLID_ OPTION Available options include lt BLANK gt ORTHO Purpose Define three dimensional solid elements including 4 noded tetrahedrons and 8 noded hexahed
529. rsion factor for length MADYMO3D GM CAL3D lengths are multiplied by UNLENG to obtain LS DYNA lengths UNTIME Unit conversion factor for time UNTIME MADYMO3D GM CAL3D time is multiplied by UTIME to obtain LS DYNA time UNFORC Unit conversion factor for force UNFORC MADYMO3D GM CAL3D force is multiplied by UNFORC to obtain LS DYNA force TIMIDL Idle time during which CAL3D or MADYMO is computing and LS DYNA3D remains inactive Important for saving computer time FLIPX Flag for flipping X coordinate of CAL3D MADYMO3D relative to the LS DYNA3D model EQ 0 off EQ 1 on FLIPY Flag for flipping Y coordinate of CAL3D MADYMO3D relative to the LS DYNA3D model EQ 0 off EQ 1 on FLIPZ Flag for flipping Z coordinate of CAL3D MADYMOS3D relative to the LS DYNA3D model EQ 0 off EQ 1 on 7 34 CONTROL LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION SUBCYL CAL3D MADYMO3D subcycling interval st of cycles EQ 0 Set to 1 EQ n number of LS DYNA time steps between each CAL3D MADYMOOD step Then the position of the contacting rigid bodies is assumed to be constant for n LS DYNA time steps This may result in some increase in the spikes in contact thus this option should be used carefully As the CAL3D MADYMO3D programs usually work with a very small number of degrees of freedom not much gain in efficiency can be achieved LS DYNA Version 960 7 35 CONTROL CONTROL CONTROL_CPU Purpose Control cpu time
530. rts or nodes of the finite element model This implementation follows that of the contact entity however it is specialized for the dummies Forces may be output using the DATABASE GCEOUT command See COMPONENT_GEBOD and Appendix K for further details Conventional CONTACT_OPTION treatment surface to surface nodes to surface etc can also be applied to the segments of a dummy To use this approach it is first necessary to determine part ID assignments by running the model through LSDYNA s initialization phase The following options are available and refer to the ellipsoids which comprise the dummy Options involving HAND are not applicable for the child dummy since its lower arm and hand share a common ellipsoid LOWER_TORSO MIDDLE_TORSO UPPER_TORSO NECK HEAD LEFT_SHOULDER RIGHT_SHOULDER LEFT_UPPER_ARM RIGHT_UPPER_ARM LEFT_LOWER_ARM RIGHT_LOWER_ARM LEFT_HAND RIGHT_HAND LEFT_UPPER_LEG RIGHT_UPPER_LEG LEFT_LOWER_LEG RIGHT_LOWER_LEG LEFT_FOOT RIGHT_FOOT LS DYNA Version 960 6 47 CONTACT CONTACT Card 1 Format Card 1 1 2 3 4 5 6 7 8 saint saint soins VARIABLE DESCRIPTION DID Dummy ID see COMPONENT_GEBOD_ OPTION SSID Slave set ID see SET NODE OPTION PART or SET_PART SSTYP Slave set type 0 node set EQ 1 part ID EQ 2 part set ID SF Penalty scale factor Useful to scale maximized penalty DF Damping option see description for CONTACT_OPTION EQ
531. s tracked only after the activation time is reached and the contact resultant forces are zero EQ 0 0 Immediate termination after null force is detected 25 4 TERMINATION LS DYNA Version 960 TITLE TITLE TITLE Purpose Define job title Card Format 1 2 3 4 5 6 7 8 LS DYNA USER INPUT VARIABLE DESCRIPTION TITLE Heading to appear on output and in output files LS DYNA Version 960 26 1 TITLE TITLE 26 2 TITLE LS DYNA Version 960 TRANSLATE TRANSLATE TRANSLATE ANSYS OPTION Available options include 4 5 corresponding to ANSYS version numbers 4 and 5 Purpose Provide a convenient route to read in ANSYS input decks as part of the LS DYNA keyword input This keyword can appear more than once anywhere in the input It is a direct interface to ANSYS file28 keyword files Card Format VARIABLE DESCRIPTION FILE Filename of file created by ANSYS see remarks below The supported options include Version ANSYS Keyword LS DYNA Keyword All N Type NODE Val1 Val2 Val3 NODE All EN Type I1 12 13 14 15 16 17 18 ELEMENT All MPDATA R5 0 LENGTH Lab MAT STLOC VAL1 VAL2 VAL3 MAT_ELASTIC LS DYNA Version 960 27 1 TRANSLATE TRANSLATE Version ANSYS Keyword LS DYNA Keyword All ET Type PART amp SECTION All R R5 0 NSET TypeeSSTLOC VALI VAL2 VAL3 PART amp SECTION 5 DFLAB NODF LabD LabF 5 NDOF eq Ui ROTi LabD eq 0 BOUNDARY_SPC_OPTION 5 NODF eq Vi LabD eq 0 IN
532. s LS DYNA is initialized by linking to an implicit code to satisfy this equation at the beginning of the calculation the constant Co is assumed to be zero The first constrained degree of freedom is eliminated from the equations of motion n 7 u uy 2 G u respectively In the implementation transformation matrix L is constructed relating the unconstrained and constrained u degrees of freedom The constrained accelerations used in A the above equation are given by 1 m L where M is the Diagonal lumped mass matrix and F is the right hand side force vector This requires the inversion of the condensed mass matrix which is equal in size to the number of constrained degrees of freedom minus one 5 48 CONSTRAINED LS DYNA Version 960 CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 CONSTRAINED LINEAR Constrain nodes 40 and 42 to move identically in the z direction When the linear constraint equation is applied it goes like this C40uz40 C42uz42 uz40 uz42 uz40 uz42 where C40 1 00 coefficient for node 40 C42 1 00 coefficient for node 42 uz40 displacement of node 40 in z direction uz42 displacement of node 42 in z direction CONSTRAINED LINEAR Ur Ur UU Ur UY UY UY UY XY UY UY XY XY XY oU UY XY UY UY UY num 2 nid dofx dofy dofz dofrx dofry dofrz
533. s default EQ 2 generate geometry based drilling constraint EQ 3 do neither Drilling rotation constraint parameter DRCPRM If adding stiffness DRCM 1 then for linear problems DRCPRM 1 0 for nonlinear problems DRCPRM 100 0 and for eigenvalue problems either 1 E 12 or E 8 is used depending on the shell element type In the latter case the input value for DRCPRM is ignored If generate geometry based drilling constraints is active DRCM 2 then DRCPRM controls the flatness test The default value of DRCPRM 10 0 for this case If the maximum deviation of a neighbor node to the best fit plane at a candidate node is less than this parameter the local geometry is declared flat and a constraint is generated on the rotation around the outward pointing normal at the candidate node AUTOSPC switch EQ 1 automatically scan the assembled stiffness matrix after all constraints have been applied looking for triples of columns associated with translations or rotations at a node or master of a rigid body If the set of 3 columns is rank deficient a constraint is generated to remove the column most associated with the null space of the singularity EQ 2 do not do the scan AUTOSPC tolerance The test for singularity is the ratio of the smallest singular value and the largest singular value If this ratio is less than AUTOTOL then the triple of columns are declared singular and a constraint is generated Default value in single precision is 1
534. s option to override true thickness g2 Scale factor for true thickness optional g3 Load curve ID defining thickness versus time optional 9 gl Shell thickness option to override true thickness NOTE The shell thickness specification is necessary if the slave surface is generated from solid elements g2 Scale factor for true thickness optional g3 Load curve ID defining thickness versus time optional 10 gl Length of edge along X axis g2 Length of edge along Y axis GEOTYP 11 gl Load curve ID defining axisymmetric surface profile about Z axis g2 Number of elements along circumference EQ 0 default set to 10 g3 Number of elements along axis EQ 0 default set to 20 EQ 1 the elements are generated from the points on the load curve g4 Number of sub divisions on load curve used to calculate contact EQ 0 default set to 1000 6 44 CONTACT LS DYNA Version 960 CONTACT 1 Infinite Plane IGTYPE 2 Sphere Z EEE a b c IGTYPE 3 Infinite Cylinder IGTYPE 4 Hyperellipsoid Figure 6 4a Contact Entities LS DYNA Version 960 6 45 CONTACT CONTACT IGTYPE 10 Finite Plane Z axis of symmetry x IGT YPE 11 Load Curve Figure 6 4b Contact Entities 6 46 CONTACT LS DYNA Version 960 CONTACT CONTACT_GEBOD_OPTION Purpose Define contact interaction between the segment of aGEBOD dummy and pa
535. s AE A ues Du eee een 29 36 Volume II ea Sod peices ee U 1 MAT ADD 2 0 00006 0000 13 MATT O OA 0 Aa 15 ute de M Uri GER 19 MAT OPTION TROPIC BLASTIG eh oot Ene eR epo ede roe Dex te ce o oe Mea s 22 MAT PLASTIC 0 0 0000 sess sese aiaiai 28 IMAT ELASTIC PLASTIC THERMALE onc ertet re are 31 NTATT SOIL AND FOAM uet nen etii DR ern nee iie bee ep he 34 MATS VISCOBDAS PIG Aussee sue diesen ee M 38 LS DYNA Version 960 1X TABLE OF CONTENTS MAT BLATZ KO RUBBER 2 42 eR rep EC HERE Te 39 MAT HIGH EXPLOSIVE BURN estate ea 40 MAT NULL 2202 do ran nein nee In 43 MAT ELASTIC PLASTIC HYDRO HH 45 MAT STBEINBERG eter e ge bis ERR RE EAE E dst ue 49 MAT STEINBERG LUND i 5 31 Sere e Te ET are 53 MAT ISOTROPIC ELASTIC 2 2 0 1200 56 MAT ISOTROPIC ELASTIC FAILURE e nern ned ag 57 MAT SOIL AND FOAM FAILURE saiisine ocrni eana a ne tea a Renting REDI 59 MAT JOHNSON COOK ics saree orgs SR enel ud te e I 60 MAT_PSEUDO TENSOR
536. s a convenient way of defining groups of nodes parts elements and segments The sets can be used in the definitions of contact interfaces loading conditions boundary condtions and other inputs Each set type must have a unique numeric identification The keyword control cards in this section are defined in alphabetical order SET_BEAM_OPTION SET_DISCRETE_ OPTION SET_NODE_OPTION SET_PART_OPTION SET SEGMENT OPTION SET SHELL OPTION SET SOLID OPTION SET TSHELL OPTION An additional option TITLE may be appended to all the SET keywords If this option is used then an addition line is read for each section in 80a format which can be used to describe the set At present LS DYNA does make use of the title Inclusion of titles gives greater clarity to input decks The GENERAL option is available for set definitions In this option the commands are executed in the order defined For example the delete option cannot delete a node or element unless the node or element was previously added via a command such as BOX or ALL LS DYNA Version 960 24 1 SET SET SET BEAM OPTION Available options include GENERATE GENERAL The last option GENERATE will generate a block of beam element ID s between a starting ID and an ending ID An arbitrary number of blocks can be specified to define the set Purpose Define a set of beam elements Card Format Card 1 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION znone The ne
537. s are recommended to avoid excessive damping Sensor Input to Activate Inflator Define if and only if RBID nonzero Skip this input if RBID O If the rigid body ID is non zero then define either the input for the user defined sensor subroutine A or define the data for the default sensor B The sensor is mounted on a rigid body which is attached to the structure The motion of the sensor is provided in the local coordinate system defined for the rigid body in the definition of the rigid material see MAT RIGID This is important since the default local system is taken as the principal axes of the inertia tensor The local system rotates and translates with the rigid material When the user defined criterion is met for the deployment of the airbag a flag is set and the deployment begins All load curves relating to the mass flow rate versus time are then shifted by the initiation time LS DYNA Version 960 1 3 AIRBAG AIRBAG A Sensor Input for User Subroutine RBID 0 See Appendix B A user supplied subroutine must be provided Define the following card sets which provide the input parameters for the user defined subroutine Up to 25 parameters may be used with each control volume Card Format Card Format Define up to 25 constants for the user subroutine Input only the number of cards necessary i e for nine constants use 2 cards 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION N Number of input parameters not
538. s consisting of a control card followed by several thermo dynamic property data cards The next card terminates the reading of this data Control Card card 1 1 2 3 4 5 6 7 8 en EJ i VARIABLE DESCRIPTION CHNAME Chemical symbol for this gas species e g N2 for nitrogen AR for argon Required for DATA 2 CHEMKIN optional for DATA 1 or DATA 3 MW Molecular weight of this gas species LCIDN Load curve specifying the input mole fraction versus time for this gas species If gt 0 FMOLE is not used FMOLE Mole fraction of this gas species in the inlet stream FMOLET Initial mole fraction of this gas species in the tank 1 36 AIRBAG LS DYNA Version 960 AIRBAG Additional thermodynamic data cards for each gas species No additional cards are needed if using the CHEMKIN database DATA 2 However the CHEMKIN database file with file name chemkin must reside in the same directory that you are running LS DYNA If DATA 1 include the following 3 cards for the NIST database The required data can be found on the NIST web site at http webbook nist gov chemistry card 1 1 2 3 4 5 6 7 8 card 2 Card 3 a LS DYNA Version 960 1 37 AIRBAG AIRBAG VARIABLE DESCRIPTION TLOW Curve fit low temperature limit TMID Curve fit low to high transition temperature THIGH Curve fit high temperature limit aw low Low temperature range NIST polynomial curve fit coefficients see be
539. s on the first three cards are active except for VC and VSF Only the SOFT and EDGE parameters on optional card A are active Only the ISYM parameter on optional card B is active LS DYNA Version 960 6 25 CONTACT CONTACT Optional Card B Reminder If Optional Card B is used then Optional Card A must be defined Optional Card A may be a blank line Optional 1 Card B 2 3 4 5 6 7 8 PENMAX THKOPT SHLTHK SNLOG ISYM DD3D SLDTHK SLDSTF Old types Old types 3 5 10 3 5 10 VARIABLE DESCRIPTION PENMAX Maximum penetration distance for old type 3 5 8 9 and 10 contact or the segment thickness multiplied by PENMAX defines the maximum penetration allowed as a multiple of the segment thickness for contact types a 3 a 5 al0 13 15 and 26 see discussion at end of section including Table 6 1 EQ 0 0 for old type contacts 3 5 and 10 Use small penetration search and value calculated from thickness and XPENE see CONTROL CONTACT EQ 0 0 for contact types a 3 a 5 a10 13 and 15 Default is 0 4 or 40 percent of the segment thickness EQ 0 0 for contact type26 Default is 200 0 times the segment thickness THKOPT Thickness option for contact types 3 5 and 10 EQ 0 default is taken from control card CONTROL CONTACT EQ 1 thickness offsets are included EQ 2 thickness offsets are not included old way SHLTHK Define if and only if THKOPT above equals 1 Shell thickness considered in type surf
540. sary Some examples include spinning bodies such as turbine blades in a jet engine high velocity impacts generating large strains in a few time steps and large time step sizes due to mass scaling in metal forming There is a significant added cost which is due in part to the added cost of the second order terms in the stress update when the Jaumann rate is used and the need to compute the strain displacement matrix at the mid point geometry This option is available for one point brick elements the selective reduced integrated brick element which uses eight integration points the fully integrated plane strain and axisymmetric volume weighted type 15 2D solid elements the fully integrated thick shell element and the following shell elements Belytschko Tsay Belyschko Tsay with warping stiffness Belyschko Chiang Wong S R Hughes Liu and the type 16 fully integrated shell element 2 Invarient node numbering for shell elements affects the choice of the local element shell coordinate system The orientation of the default local coordinate system is based on the shell normal vector and the direction of the 1 2 side of the element If the element numbering is LS DYNA Version 960 7 3 CONTROL CONTROL permuted the results will change in irregularly shaped elements With invarient node numbering permuting the nodes shifts the local system by an exact multiple of 90 degrees In spite of its higher costs lt 5 the invarient local system is
541. section using the CHANGE VELOCITY options The velocity field in the full deck part of the input is ignored LS DYNA Version 960 RESTART CHANGE OPTION Available options are BOUNDARY CONDITION CONTACT SMALL PENETRATION CURVE DEFINITION RIGID BODY CONSTRAINT RIGID BODY STOPPER STATUS REPORT FREQUENCY THERMAL PARAMETERS VELOCITY VELOCITY NODE VELOCITY RIGID BODY VELOCITY ZERO Purpose Change some solution options LS DYNA Version 960 29 3 RESTART RESTART For BOUNDARY CONDITION option define an arbitrary number of cards giving the nodal ID and the additional translational displacement boundary condition code Previous boundary condition codes will continue to be imposed i e a fixed node cannot be freed with this option This input terminates when the next card is encountered Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Nodal point ID see also NODE BCC New translational boundary condition code EQ 1 constrained x displacement EQ 2 constrained y displacement EQ 3 constrained z displacement EQ 4 constrained x and y displacements EQ 5 constrained y and z displacements EQ 6 constrained z and x displacements EQ 7 constrained x y and z displacements 29 4 RESTART LS DYNA Version 960 RESTART For CONTACT SMALL PENETRATION option define an arbitrary number of cards giving a list of contact surface ID numbers where the small penetration check is to be turned on
542. seesseeses 18 1 INTERFACE LINKING DISCRETE NODE 22 222 2202022020 040 20122280100 18 2 INTERFACE_LINKING_SEGMENT sscssssssssssesssesssssseessessscsssesssssecssessecsseeseseseeses 18 3 INTERFACE LINKING 18 4 AINTERERCH IE nee Ne ER ed ehe a 18 5 INTERFACE SPRINGBACK OPTIONI OPTION 18 6 19 1 SEDADCBEAMSOBPION ua een 19 2 19 4 WIND BODY SORPTION ra aa ton oN lia yd 19 6 _ _ 19 10 MISO ABR ODE seele esse 19 12 SEOAD DENSITY DEPTH u san nen 19 14 LOAD HEAT GENERATION OPTION eene 19 16 OADMASK Ekel 19 17 NODE OPTION Gau Reel 19 19 HLOADRIGDIBODY en ee ee en 19 22 TOADISEGMENE ee 19 24 SEORDESEGMENT SET insert 19 26 MUO ADSM SOP TION And eisen nee 19 28 LS DYNA Version 960 TABLE OF CONTENTS UB 01 1 0 8 EATE 19 30 LOAD SUPERPLASTIC FORMING eerte eee tne 19 33 SLOXD THERMAL OPTION A 19 35 NODE Lt uM D IM C M yes 20 1 SNODEB are ten A 20 2 Der tees unt Mu e Ca de M LE I el ME 20 4 Reh eta teak eel enel 21 1 PART OPTIONI OPTION2 OPTION3 OPTIOMA ees 212 SBARTANODESU an DD Ch DE RE 21 10 SPA
543. ship given by u FD FS FD e DCAvl Dynamic coefficient of friction The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact FD FS P Exponential decay coefficient The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact FD FS FD e PO Parameter to allocate memory for bucket sort pair information Birth time for contact Death time for contact Surface offset from midline for 2D shells of slave surface EQ 0 0 default to 1 GT 0 0 scale factor applied to actual thickness LT 0 0 absolute value is used as the offset Surface offset from midline for 2D shells of master surface EQ 0 default to 1 GT 0 scale factor applied to actual thickness LT 0 absolute value is used as the offset Normal direction flag for 2D shells of slave surface EQ 0 Normal direction is determined automatically EQ 1 Normal direction is in the positive direction EQ 1 Normal direction is in the negative direction LS DYNA Version 960 VARIABLE NDM IPF COF CF FRAD HTC GCRIT GMAX LS DYNA Version 960 CONTACT DESCRIPTION Normal direction flag for 2D shells of master surface EQ 0 Normal direction is determined automatically EQ 1 Normal direction is in the positive direction EQ 1 Normal direction is in the negative direction Initial penetration flag for explicit analysis
544. spotweld not the spotweld itself A least squares algorithm is used to generate the nodal values of plastic strains at the nodes from the element integration point values The plastic strain is integrated through the element and the average value is projected to the nodes via a least square fit This option should only be used for the material models related to metallic plasticity and can result in slightly increased run times Brittle failure of the spotwelds occurs when n m Sn Ss where fn and f are the normal and shear interface force Component fn contributes for tensile values only When the failure time t is reached the nodal rigid body becomes inactive and the constrained nodes may move freely In Figure 5 1 the ordering of the nodes is shown for the 2 node and 3 node spotwelds This order is with respect to the local coordinate system where the local z axis determines the tensile direction The nodes in the spotweld may coincide The failure of the 3 node spotweld may occur gradually with first one node failing and later the second node may fail For n noded spotwelds the failure is progressive starting with the outer nodes 1 and n and then moving inward LS DYNA Version 960 5 7 CONSTRAINED CONSTRAINED to nodes 2 and n 1 Progressive failure is necessary to preclude failures that would create new rigid bodies ee 2 NODE SPOTWELD 3 NODE SPOTWELD n NODE SPOTWELD node 1 Figure 5 1 Nodal order
545. stant strain and curvature representation i e they pass all the first order patch tests In addition the elements have behavior approaching linear bending cubic displacement in the plate bending configuration a The membrane component of all elements is based on an 8 node 6 node isoparametric mother element which incorporates nodal in plane rotations through cubic displacement constraints of the sides Taylor 1987 Wilson 2000 b The plate component of element 18 is based on the Discrete Kirchhoff Quadrilateral DKQ Batoz 1982 Because the Kirchhoff assumption is enforced the DKQ is transverse shear rigid and can only be used for thin shells No transverse shear stress information is available The triangle is based on a degeneration of the DKQ This element sometimes gives slightly lower eigenvalues when compared with element type 20 c The plate component of element 20 is based on the 8 node serendipity element At the mid side the parallel rotations and transverse displacements are constrained and the normal rotations are condensed to yield a 4 node element The element is based on thick plate theory and is recommended for thick and thin plates d The quadrilateral elements contain a warpage correction using rigid links The membrane component of element 18 has a zero energy mode associated with the in plane rotations This is automatically suppressed in a non flat shell by the plate stiffness of the adjacent elements Elemen
546. strained points i 1 2 EIDi Shell element ID i 1 2 PSF Penalty scale factor Default 1 0 FAILA Axial force resultant failure value Skip if zero FAILS Shear force resultant failure value Skip if zero FAILM Moment resultant failure value Skip if zero 5 58 CONSTRAINED LS DYNA Version 960 CONSTRAINED CONSTRAINED RIGID BODIES Purpose Merge two rigid bodies One rigid body called slave rigid body is merged to the other one called a master rigid body Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PIDM Master rigid body part ID see PART PIDS Slave rigid body part ID see PART Remarks The slave rigid body is merged to the master rigid body The inertial properties computed by LS DYNA are based on the combination of the master rigid body plus all the rigid bodies which are slaved to it unless the inertial properties of the master rigid body are defined via the PART_ INERTIA keyword in which case those properties are used for the combination of the master and slave rigid bodies Note that a master rigid body may have many slaves Rigid bodies must not share common nodes since each rigid body updates the motion of its nodes independently of the other rigid bodies If common nodes exists between rigid bodies the rigid bodies sharing the nodes must be merged It is also possible to merge rigid bodies that are completely separated and share no common nodal points or boundaries All actions valid
547. sure solver EQ 0 MAXIT 200 default Set the interval to check the convergence criteria for the pressure solver EQ 0 ICHKIT 5 default Activate the output of diagnostic information from the pressure solver EQ 0 Diagnostic information is off default EQ 1 Diagnostic information is on NOTE during execution sense switch Iprint can be used to toggle this flag on or off Activate the generation of a convergence history file for the pressure solver The ASCII history file is ppe his EQ 0 Convergence history is off default EQ 1 Convergence history is on Set the convergence criteria for the pressure solver EQ 0 EPS 1 0e 5 default Set the number of A conjugate vectors to use during the iterative pressure solve EQ 0 NVEC 5 default LT 0 A conjugate projection is disabled Set the stabilization type EQ 0 ISTAB 1 default EQ 1 Local jump stabilization EQ 2 Global jump stabilization EQ 1 No stabilization is active Stabilization parameter for ISTAB 1 2 Valid values for the stabilization parameter are 0 lt 1 EQ 0 BETA 0 05 default Solid element set ID or shell element set ID see SET_SOLID SET_SHELL_OPTION to be used for the prescription of hydrostatic pressure Set the hydrostatic pressure level This value multiplies the values of the load curve specified with the LCID option EQ 0 PLEV 0 0 default Load curve to be used for setting the hydrostatic pressur
548. sured relative to the computed offset 5 42 CONSTRAINED LS DYNA Version 960 CONSTRAINED 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 CONSTRAINED JOINT STIFFNESS GENERALIZED 5 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 5 Define a joint stiffness for the revolute joint described 5 CONSTRAINED JOINT REVOLUTE 6 Attributes of the joint stiffness 5 Used for defining a stop angle of 30 degrees rotation 5 i e the joint allows a positive rotation of 30 degrees and then imparts an elastic stiffness to prevent futher rotation 5 Define between rigid body part 1 and rigid body part 2 Define a local coordinate system along the revolute axis 5 on rigid body nodes 1 2 and 3 cid 5 This is used to 5 define the revolute angles phi PH theta PS The elastic stiffness per unit radian for the stop angles 5 are 100 10 10 for and PS respectively 5 Values not specified are not used during the simulation CONSTRAINED JOINT STIFFNESS GENERALIZED Sse Sas sth eee De te Si aS aie MO nde fete SD OS 5 jsid pida pidb cida cidb 1 1 2 5 5 lcidph lcidt lcidps dleidph dlcidt dlcidps 5 esph fmps est fmt esps fmps 100 0 10 0 10 0 5 nsaph psaph nsat psat nsaps psaps 30 0 DEFINE COORDINATE NODES 5 cid nl n2 n3 5 1 2 3 5 5555555555555
549. t GT 10 trapezoidal or user defined rule Through thickness integration for the two dimensional elements options 11 15 above is not meaningful consequently the default is equal to 1 integration point Fully integrated two dimensional elements are available for options 13 and 15 by setting NIP equal to a value of 4 corresponding to 2 by 2 Gaussian quadrature If is 0 or 1 and the SIMPLIFIED_JOHNSON_COOK model is used then a resultant plasticity formulation is activated NIP is always set to if a constitutive model based on resultants is used Printout option EQ 1 0 average resultants and fiber lengths EQ 2 0 resultants at plan points and fiber lengths EQ 3 0 resultants stresses at all points fiber lengths LS DYNA Version 960 VARIABLE QR IRID ICOMP SETYP Tl T2 T3 T4 NLOC MAREA Bl B2 B3 B8 Bnip LS DYNA Version 960 SECTION DESCRIPTION Quadrature rule or Integration rule ID see SHELL LT 0 0 absolute value is specified rule number EQ 0 0 Gauss Lobatto up to 10 points are permitted EQ 1 0 trapezoidal not recommend for accuracy reasons Flag for orthotropic anisotropic layered composite material model This option applies to material types 22 23 33 34 36 40 41 50 54 56 58 59 103 116 and 194 EQ 1 a material angle in degrees is defined for each through thickness integration point Thus each layer has one integrat
550. t be set to 2 or 3 in the SECTION_BEAM input e New discrete element constitutive models are available MAT ELASTIC SPRING DISCRETE BEAM MAT INELASTIC SPRING DISCRETE BEAM MAT ELASTIC 6DOF SPRING DISCRETE BEAM MAT INELASTIC 6DOF SPRING DISCRETE BEAM The latter two can be used as finite length beams with local coordinate systems e Moving SPC s are optional in that the constraints are applied in a local system that rotates with the 3 defining nodes e A moving local coordinate system CID be used to determine orientation of discrete beam elements e Modal superposition analysis can be performed after an eigenvalue analysis Stress recovery is based on type 18 shell and brick SMP only Rayleigh damping input factor is now input as a fraction of critical damping i e 0 10 The old method required the frequency of interest and could be highly unstable for large input values e Airbag option SIMPLE PRESSURE VOLUME allows for the constant CN to be replaced by a load curve for initialization Also another load curve can be defined which allows CN to vary as a function of time during dynamic relaxation After dynamic relaxation CN can be used as a fixed constant or load curve Hybrid inflator model utilizing CHEMKIN and NIST databases is now available Up to ten gases can be mixed Option to track initial penetrations has been added in the automatic SMP contact types rather than moving the nodes back to the surface This optio
551. t in the road surface XC An array equal in length to 3 x NPDS This array defines the global x y and z coordinates of each point For each road surface define the following NSID sets of data ID Rigid surface ID NS Number of segments in rigid surface IXRS An array equal in length to 4 x NS This is the connectivity of the rigid surface in the internal numbering system At the end of each state 6 x NVELQ words of information are written For each road surface the x y and z displacements and velocities are written If the road surface is fixed a null vector should be output Skip this section if NVELQ 0 LS POST currently displays rigid surfaces and animates their motion 6 54 CONTACT LS DYNA Version 960 CONTACT CONTACT_1D Purpose Define one dimensional slide lines for rebar in concrete Card Format Card 1 1 2 3 4 5 6 7 8 me fete tet tet ete VARIABLE DESCRIPTION NSIDS Nodal set ID for the slave nodes see SET NODE NSIDM Nodal set ID for the master nodes see SET NODE ERR External radius of rebar SIGC Compressive strength of concrete GB Bond shear modulus SMAX Maximum shear strain EXP Exponent in damage curve Remarks With this option the concrete is defined with solid elements and the rebar with truss elements each with their own unique set of nodal points A string of consecutive nodes called slave nodes related to the truss elements may slide along a string of consecutive nodes
552. t to define only TWGHTX even if its degree of freedom is inactive since the other factors are set equal to this input value as the default There is no requirement on the values that are chosen as the weighting factors i e that they sum to unity The default value for the weighting factor is unity TWGHTY Weighting factor for node INID with active degrees of freedom IDOF This weight scales the y translational component TWGHTZ Weighting factor for node INID with active degrees of freedom IDOF This weight scales the z translational component RWGHTX Weighting factor for node INID with active degrees of freedom IDOF This weight scales the x rotational component RWGHTY Weighting factor for node INID with active degrees of freedom IDOF This weight scales the y rotational component RWGHTZ Weighting factor for node INID with active degrees of freedom IDOF This weight scales the z rotational component 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5555 CONSTRAINED INTERPOLATION Beam to solid coupling 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Tie beam element to solid element 5 The node of the beam to be tied does not share a common node with the solids If the beam node is shared for example then set ddof 456 CONSTRAINED INTERPOLATION Dee u Ds ere ies cee aces be sau P ed 5 icid dnid ddof
553. t 20 has no spurious zero energy modes 23 18 SECTION LS DYNA Version 960 SECTION 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 SECTION SHELL 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 5 Define a shell section that specifies the following 5 elform 10 Belytschko Wong Chiang shell element formulation nip 3 Three through the shell thickness integration points 5 tl t4 2 0 shell thickness of 2 mm at all nodes SECTION SHELL Gos aig od Severe aeons ED DD 109 rect Paarl iS 5 sid elform shrf nip propt gr irid icomp i 10 3 0000 5 t1 t2 t3 t4 nloc 2 0 2 0 2 50 2 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 23 19 SECTION SECTION SECTION_SOLID_ OPTION Options include lt BLANK gt ALE such that the keyword cards appear SECTION_SOLID SECTION_SOLID_ALE Purpose Define section properties for solid continuum and fluid elements Card 1 define for all options Card 1 1 2 3 4 5 6 7 8 Card 2 define only for the ALE option Also see ALE_SMOOTHING for the smoothing definition Cards 2 1 2 3 4 5 6 7 8 AFAC BFAC CFAC DFAC START END AAFAC m fe fe fe fe fete fe 23 20 SECTION LS DYNA Version 960 VARIABLE SECID ELFORM AFAC BFAC CFAC DFAC START END AAFAC
554. t 40 ms assuming time unit is ms 5855 Optional Cards A and B not specified default values will be used SET PART LIST 5 sid 5 5 pid2 pid3 pid4 28 97 88 92 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 6 36 LS DYNA Version 960 CONTACT 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 CONTACT DRAWBEAD 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 Define draw bead contact the draw bead is to be made from the nodes specified in node set 2 the master segments are to be those found in the box defined by box 2 that are in part 18 include slave and master forces in interface file spr mpr 1 CONTACT DRAWBEAD ne lee EB Dr En Dana Dear RENS Or lau Den ssid msid sstyp mstyp sboxid mboxid spr mpr 2 18 4 3 2 1 1 fs fd de ve vdc penchk bt dt 0 10 sfs sfm sst mst sfst sfmt fsf vsf 555 Card 4 required because it s a drawbead contact lcdidrf lcidnf dbath dfscl numint 3 0 17436 2 0 lcdidrf 3 load curve 3 specifies the bending component of the restraining force per unit draw bead length dbdth 0 17436 drwa bead depth dfscl 2 0 scale load curve 3 lcdidrf by 2 Optional Cards A and B not specified default values will be used DEFINE BOX boxid xm xmx ym ymx zm zmx 2 0 000E 00 6 000E 00 6 000E 00 1 000E 02 1 000E 03 1 000E 03 SET
555. t Lanczos code is from BCSLIB EXT Boeing s Extreme Mathematical Library This method is much more robust and efficient than subspace iteration Subscape iteration is only included for comparison and testing purposes When using Block Shift and Invert Lanczos the user can specify a semifinite or finite interval region in which to compute eigenvalues Setting LFLAG 1 changes the left end point from infinity to the value specified by LFTEND Setting RFLAG 1 changes the right end point from infinity to the values given by RHTEND If the interval includes CENTER default value of 0 0 then the problem is to compute the NEIG eigenvalues nearest to CENTER If the interval does not include CENTER the problem is to compute the smallest in magnitude NEIG eigenvalues If all of the eigenvalues are desired in an interval where both end points are finite just input a large number for NEIG The software will automatically compute the number of eigenvalues in the interval and lower NEIG to that value The most general problem specification is to compute NEIG eigenvalues nearest CENTER in the interval LFTEND RHTEND Computing the lowest NEIG eigenvalues is equivalent to computing the NEIG eigenvalues nearest 0 0 For some problems it is useful to override the internal heuristic for picking a starting point for Lanczos shift strategy that is the initial shift In these rare cases the user may specify the initial shift via the parameter SHFSCL SHFSCL shoul
556. t PID 5 1 At t midsurface 5 Figure 17 4 In the user defined shell integration rule the ordering of the integration points is arbitrary LS DYNA Version 960 17 7 INTEGRATION INTEGRATION 17 8 INTEGRATION LS DYNA Version 960 INTERFACE INTERFACE INTERFACE_COMPONENT_OPTION Options include NODE SEGMENT Purpose Define an interface for linking calculations This card applies to the first analysis for storing interfaces in the file specified by Z isfl on the execution command line The output interval used to write data to the interface file is controlled by OPIFS on CONTROL_OUTPUT This capability allows the definition of interfaces that isolate critical components A database is created that records the motion of the interfaces In later calculations the isolated components can be reanalyzed with arbitrarily refined meshes with the motion of their boundaries specified by the database created by this input The interfaces defined here become the masters in the tied interface options Each definition consists of a set of cards that define the interface Interfaces may consists of a set of four node segments for moving interfaces of solid elements a line of nodes for treating interfaces of shells or a single node for treating beam and spring elements Card Format VARIABLE DESCRIPTION SID Set ID see SET_NODE or SET_SEGMENT LS DYNA Version 960 18 1 INTERFACE INTERFACE INTERFACE LINK
557. t and causes the input line to be ignored Data blocks are not a requirement for LS DYNA but they can be used to group nodes and elements for user convenience Multiple blocks can be defined with each keyword if desired as shown above It would be possible to put all nodal points definitions under one keyword NODE or to define one NODE keyword prior to each node definition The entire LS DYNA input is order independent with the exception of the optional keyword END which defines the end of input stream Without the END termination is assumed to occur when an end of file is encountered during the reading Figure I 1 attempts to show the general philosophy of the input organization and how various entities relate to each other In this figure the data included for the keyword ELEMENT is the element identifier EID the part identifier PID and the nodal points identifiers the NID s defining the element connectivity 1 2 N3 4 The nodal point identifiers are defined in the NODE section where each NID should be defined just once A part defined with the PART keyword has a unique part identifier PID a section identifier SID a material or constitutive model identifier MID an equation of state identifier EOSID and the hourglass control identifier HGID The SECTION keyword defines the section identifier SID where a section has an element formulation specified a shear factor SHRF a numerical integration rule NIP and s
558. t be changed to deformable Deformable parts may be switched to rigid at the start of the calculation by specifying them on the DEFORMABLE RIGID card Part switching may be specified on a restart see RESTART section of this manual or it may be performed automatically by use of the DEFORMABLE TO RIGID AUTOMATIC cards The DEFORMABLE TO RIGID INERTIA cards allow inertial properties to be defined for deformable parts that are to be swapped to rigid at a later stage It is not possible to perform part material switching on a restart if it was not flagged in the initial analysis The reason for this is that extra memory needs to be set up internally to allow the switching to take place If part switching is to take place on a restart but no parts are to be switched at the start of the calculation no inertia properties for switching and no automatic switching sets are to be defined then just define one DEFORMABLE TO RIGID card without further input LS DYNA Version 960 11 1 DEFORMABLE TO RIGID DEFORMABLE TO RIGID DEFORMABLE TO RIGID Purpose Define materials to be switched to rigid at the start of the calculation Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of the part which is switched to a rigid material also see PART MRB Part ID of the master rigid body to which the part is merged If zero the part becomes either an independent or master rigid body 11 2 DEFORMABLE_TO_RIGID LS DYNA Version 96
559. t types see earlier in this section for the list later in this section for details of Card 4 Optional 1 2 3 4 5 6 7 8 Card A SOFT SOFSCL LCIDAB MAXPAR EDGE DEPTH BSORT FRCFRQ VARIABLE DESCRIPTION SOFT Soft constraint option EQ 0 penalty formulation EQ 1 soft constraint formulation EQ 2 pinball segment based contact EQ 4 constraint approach for FORMING contact option The soft constraint may be necessary if the material constants of the elements which make up the surfaces in contact have a wide variation in the elastic bulk modulii In the soft constraint option the interface stiffness is based on the nodal mass and the global time step size This method of computing the interface stiffness will typically give much higher stiffness value than would be obtained by using the bulk modulus therefore this method the preferred approach when soft foam materials interact with metals See the remark below for the alternate penalty formulation SOFSCL Scale factor for constraint forces of soft constraint option default 10 Values greater than 5 for single surface contact and 1 0 for a one way treatment are inadmissible LCIDAB Load curve ID defining airbag thickness as a function of time for type al3 contact AIRBAG SINGLE SURFACE MAXPAR Maximum parametric coordinate in segment search values 1 025 and 1 20 recommended Larger values can increase cost If zero the default is set to 1 025 This f
560. t weld may occur gradually with first one node failing and later the second node may fail LS DYNA Version 960 5 9 CONSTRAINED CONSTRAINED Figure 5 2 Nodal ordering and orientation of the local coordinate system is shown for fillet weld failure The angle is defined in degrees 5 10 CONSTRAINED LS DYNA Version 960 CONSTRAINED Additional Card required for the BUTT option Card 2 1 2 3 4 5 6 7 8 w fete efe feefee VARIABLE DESCRIPTION TFAIL Failure time for constraint set tr default 1 E 20 EPSF Effective plastic strain at failure defines ductile failure SIGY Of stress at failure for brittle failure BETA B failure parameter for brittle failure L L length of fillet butt weld see Figure 5 2 and 5 3 D d thickness of butt weld see Figure 5 3 LT Li transverse length of butt weld see Figure 5 3 Remarks Ductile butt weld failure due to plastic straining is treated identically to spotweld failure Brittle failure of the butt welds occurs when Bjo 37 7 20y where On normal stress Tn Shear stress in direction of weld local t shear stress normal to weld local z of failure stress B failure parameter Component is nonzero for tensile values only When the failure time t is reached the nodal rigid body becomes inactive and the constrained nodes may move freely The nodes in the butt weld may coincide LS DYNA Version 960 5 11 CONSTRAINED CONSTR
561. tablish a relationship known from the literature The scale factor is simply used to scale the given values This simple model can be used when an initial pressure is given and no leakage no temperature and no input mass flow is assumed A typical application is the modeling of air in automobile tires The load curve LCIDDR can be used to ramp up the pressure during the dynamic relaxation phase in order to avoid oscillations after the desired gas pressure is reached In the DEFINE_CURVE section this load curve must be flagged for dynamic relaxation After initialization either the constant or load curve ID ICNI is usedto determine the pressure LS DYNA Version 960 1 7 AIRBAG AIRBAG Additional cards required for SIMPLE_AIRBAG_MODEL option Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION CP Heat capacity at constant pressure CV Heat capacity at constant volume T Temperature of input gas LCID Load curve ID specifying input mass flow rate See DEFINE_CURVE MU Shape factor for exit hole u LT 0 0 Iul is the load curve number defining the shape factor as a function of absolute pressure A Exit area A GE 0 0 is the exit area and is constant in time LT 0 0 IAI is the load curve number defining the exit area as a function of absolute pressure PE Ambient pressure pe RO Ambient density 1 8 AIRBAG LS DYNA Version 960 AIRBAG VARIABLE DESCRIPTION LOU Optiona
562. tabulated compaction tabulated TENSOR pore collapse Burton et al 1982 The ignition and growth EOS was adapted from KOVEC Woodruff 1973 the other subroutines programmed by the authors are based in part on the cited references and are nearly 100 percent vectorized The forms of the first five equations of state are also given in the KOVEC user s manual and are retained in this manual The high explosive programmed burn model is described by Giroux Simo et al 1988 The orthotropic elastic and the rubber material subroutines use Green St Venant strains to compute second Piola Kirchhoff stresses which transform to Cauchy stresses The Jaumann stress rate formulation is used with all other materials with the exception of one plasticity model which uses the Green Naghdi rate SPATIAL DISCRETIZATION The elements shown in Figure I 2 are presently available Currently springs dampers beams membranes shells bricks thick shells and seatbelt elements are included The first shell element in DYNA3D was that of Hughes and Liu Hughes and Liu 1981a 1981b 1981c implemented as described in Hallquist et al 1985 Hallquist and Benson 1986 This element designated as HL was selected from among a substantial body of shell element literature because the element formulation has several desirable qualities tis incrementally objective rigid body rotations do not generate strains allowing for the treatment of finite strains that o
563. te mas o temperature density Gt ELOUT Xy yz zx strain lower surface strain s moment resultant yield function upper surface strain t moment resultant torsional resultant GCEOUT Translational Components Rotational Components y force y moment z force z moment 9 4 DATABASE LS DYNA Version 960 DATABASE JNTFORC damping energy sliding interface energy i pe x y z velocity a lt n element id controlling time step NCFORC NODOUT wlodity o a force aeceleration 7770 rotational velocity S rotational acceleration total hourglass energy a PO PO St hourglass energy total internal energy 4 6600 2 1 velocity fere xyz accraon SECFORC SPCFORC SWFORC xyz 0147 area 114 J resultant force 2 Ideni S FF LS DYNA Version 960 9 5 DATABASE DATABASE Remarks 1 The kinetic energy quantities in the MATSUM and GLSTAT files may differ slightly in values for several reasons First the rotational kinetic energy is included in the GLSTAT calculation but is not included in MATSUM Secondly the energies are computed element by element in MATSUM for the deformable materials and consequently nodes which are merged with rigid bo
564. ted 2 same keywords LS DYNA usually contain more options than the NASTRAN input Therefore to make it complete we add some extra parameters to the NASTRAN keywords For those extras we use the italics to distinguish from the standard ones These additional parameters have to be added to the NASTRAN deck by the user to make the translation complete Card Format For further explanation see ELEMENT DISCRETE Sen EO ERED EE 3 Current NASTRAN only supports shell element with constant thickness 27 6 TRANSLATE LS DYNA Version 960 TRANSLATE For further explanation see PART and SECTION_SOLID 4 THRU command for SPC SPC1 is not supported in the current translation 5 For RBE2 keyword if any of the rotational DOF 4 5 6 appears in the constraint LS DYNA will treat it as nodal rigid body constraint Otherwise LS DYNA will use nodal constraints to treat this RBE2 LS DYNA Version 960 27 7 TRANSLATE TRANSLATE 27 8 TRANSLATE LS DYNA Version 960 USER USER USER_INTERFACE_OPTION Available options include CONTROL FRICTION Purpose Define user defined input and allocate storage for user defined subroutines for the contact algorithms See also CONTROL_CONTACT The CONTROL option above allows the user to take information from the contact interface for further action e g stopping the analysis A sample user subroutine is provided in Appendix D The FRICTION option may be used to
565. ter z coordinate of initial position of mass center x coordinate of final position of mass center y coordinate of final position of mass center z coordinate of final position of mass center x component of mass center velocity y component of mass center velocity z component of mass center velocity First rotation axis code EQ 1 Initially aligned with global x axis EQ 2 Initially aligned with global y axis EQ 3 Initially aligned with global z axis Second rotation axis code Third rotation axis code Rotation angle about the first rotation axis degrees Rotation angle about the second rotation axis degrees Rotation angle about the third rotation axis degrees Angular velocity component for the first axis radian second Angular velocity component for the second axis radian second Angular velocity component for the third axis radian second LS DYNA Version 960 INITIAL gravity Y Figure 16 1 The vehicle pictured is to be oriented with a successive rotation sequence about the yaw pitch and roll axes respectively Accordingly AAXIS 3 BAXIS 1 and CAXIS 2 The direction of gravity is given by GRAV 3 LS DYNA Version 960 16 19 INITIAL INITIAL INITIAL_VELOCITY Purpose Define initial nodal point translational velocities using nodal set ID s This may also be used for sets in which some nodes have other velocities See NSIDEX below Card Format Card 1 6 7 8 mite ist 1 Card
566. terms of the flexible body equations and its cost grows approximately as the square of the number of modes The second formulation ignores most of the second order terms appearing in the exact equations and its cost grows linearly with the number of modes Users are responsible for determining which formulation is appropriate for their problems In general if the angular velocities are small and if the deflections are small with respect to the geometry of the system it is safe to use the second faster formulation 21 12 PART LS DYNA Version 960 PART PART_MOVE Purpose Translate shell part by an increment This option currently applies only to shell elements Define one card Card Format 18 3E16 0 Card 1 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION PID Part identification XMOV Move shell part ID PID in the x direction by the incremental distance XMOV YMOV Move shell part ID PID in the y direction by the incremental distance YMOV ZMOV Move shell part ID PID in the z direction by the incremental distance ZMOV LS DYNA Version 960 21 13 PART PART 21 14 PART LS DYNA Version 960 RIGIDWALL RIGIDWALL Two keywords are used in this section to define rigid surfaces RIGIDWALL GEOMETRIC OPTION OPTION RIGIDWALL PLANAR OPTION OPTION OPTION The RIGIDWALL option provides a simple way of treating contact between a rigid surface and nodal points of a deformable body called slave nodes Slave nodes w
567. the conditions is satisfied Termination by other means than TERMINATION input is controlled by the CONTROL TERMINATION control card Note that this type of termination is not active during dynamic relaxation Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of rigid body see PART_OPTION STOP Stop criterion EQ 1 global x direction EQ 2 global y direction EQ 3 global z direction EQ 4 stop if displacement magnitude is exceeded MAXC Maximum most positive displacement options 1 2 3 and 4 EQ 0 0 MAXC set to 1 0e21 MINC Minimum most negative displacement options 1 2 and 3 above only EQ 0 0 MINC set to 1 0e21 LS DYNA Version 960 25 3 TERMINATION TERMINATION TERMINATION CONTACT Purpose The analysis terminates when the magnitude of the contact interface resultant force is zero If more than one contact condition is input the analysis stops when any of the conditions is satisfied Termination by other means than TERMINATION input is controlled by the CONTROL TERMINATION control card Note that this type of termination is not active during dynamic relaxation Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION CID Contact ID The contact ID is defined by the ordering of the contact input unless the TITLE option which allows the CID to be defined is used in the CONTACT section ACTIM Activation time DUR Time duration of null resultant force prior to termination This time i
568. the largest diagonal 3 The deonation points should be either within or on the boundary of the explosive Offset points may fail to initiate the explosive LS DYNA Version 960 16 5 INITIAL INITIAL 4 Check the computed lighting times in the post processor LS POST The lighting times may be displayed at time 0 state 1 by plotting component 7 a component normally reserved for plastic strain for the explosive material The lighting times are stored as negative numbers The negative lighting time is replaced by the burn fraction when the element ignites Line detonations may be approximated by using a sufficient number of detonation points to define the line Two many detonation points may result in significant initialization cost The pressure versus time curve for the acoustic option is defined by Pressure profile at standoff point Standoff point Structure jy A Reference node where pressure begins at t 0 This node is typically one element away from the structure Acoustic mesh boundary is treated as a transmitting boundary Detonation point Figure 16 1 Initialization of the initial pressures due to an explosive disturbance is performed in the acoustic media LS DYNA automatically determines the acoustic mesh boundary and applies the pressure time history to the boundary This option is only applicable to the acoustic element formulation see SECTION SOLID 16 6 INITIAL LS DYNA Version 960 INITIAL
569. the time step may be increased for IAUTO 3 EQ 0 10 DTINIT default Remarks 1 There are multiple solver options for a variety of flow related physics in LS DYNA The selection of the time step control mechanism is dependent upon the flow solver that is selected may be used with any of the solution methods AUTO 2 forces the time step to be based on either stability or the CFL number see CONTROL_CFD_GENERAL LS DYNA Version 960 7 13 CONTROL CONTROL for either the explicit INSOL 1 or the semi implicit INSOL 3 methods For IAUTO 2 the ICKDT parameter may be used to control the interval at which the time step is checked and adjusted The use of the second order predictor corrector time step control is restricted to the full implicit solver 1 INSOL 3 and IADVEC 40 2 For IAUTO 3 the default maximum time step DTMAX is set 10 times larger than the starting time step DTINIT 7 14 CONTROL LS DYNA Version 960 CONTROL CONTROL_CFD_GENERAL Purpose Set solver parameters for the Navier Stokes flow solver CONTROL_CFD_OPTION where OPTION MOMENTUM TRANSPORT and PRESSURE are used in conjunction with this keyword to control the flow solver options Material models may be specified with the MAT_CFD__OPTION keyword input and turbulence models are activated with the CONTROL_CFD_TURBULENCE keyword input Card Format VARIABLE DESCRIPTION INSOL Set the solver type EQ 0 INSOL 3 default
570. their motion modified independently of the stonewall LS DYNA Version 960 22 19 RIGIDWALL RIGIDWALL en E pt Tail of normal vector is the origin and corner point if extent of stonewall is finite Figure 22 3 Vector n is normal to the stonewall An optional vector can be defined such that m nX 1 The extent of the stonewall is limited by defining L and M LENM A zero value for either of these lengths indicates that the stonewall is infinite in that direction 22 20 RIGIDWALL LS DYNA Version 960 RIGIDWALL 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 RIGIDWALL PLANAR MOVING FORCES 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Define moving planar rigid wall 5 that is parallel to the y z plane starting at x 250 mm with an initial velocity of 8 94 mm ms in the negative z direction 5 that has a mass of 800 kg which prevents all nodes in the model from penetrating the wall with a friction coefficint for nodes sliding along the wall of 0 1 track the motion of the wall by creating a node numbered 99999 5 at the tail of the wall and assigning the node to move with the wall RIGIDWALL PLANAR MOVING FORCES Sig ba sehen Dr 2a Din BoD ease Dial Sain ts Den ial Ie e beware 5 nsid nsidex boxid 0 0 0 xt yt zt xh yh zh fric 250 0 0 0 0 0 0 0 0 0 0 0 0 1 SW mass SW vel 8
571. tial rotational velocity of rigid body about x axis initial rotational velocity of rigid body about y axis initial rotational velocity of rigid body about z axis 21 7 PART PART VARIABLE DESCRIPTION XL x coordinate of local x axis Origin lies at 0 0 0 YL y coordinate of local x axis ZL z coordinate of local x axis XLIP x coordinate of vector in local x y plane YLIP y coordinate of vector in local x y plane ZLIP z coordinate of vecotr in local x y plane CID Local coordinate system ID see DEFINE COORDINATE With this option leave fields 1 6 blank CMSN CAL3D segment number MADYMO system number See the numbering in the corresponding program MDEP MADYMO ellipse plane number GT 0 ellipse number EQ 0 default LT 0 absolute value is plane number MOVOPT Flag to deactivate moving for merged rigid bodies see CONSTRAINED_ RIGID_BODIES This option allows a merged rigid body to be fixed in space while the nodes and elements of the generated CAL3D MADYMO parts are repositioned 0 merged rigid body is repositioned EQ 1 merged rigid body is not repositioned FS Static coefficient of friction The functional coefficient is assumed to be dependent on the relative velocity vpe of the surfaces in contact FD FS FD e P l FD Dynamic coefficient of friction The functional coefficient is assumed to be dependent on the relative velocity vreg of the surfaces in contact FD FS P
572. tion of boundary conditions for velocities mass concentration of each species temperature turbulent kinetic energy etc Additionally the keyword optionally provides for prescribing all velocities for example on a no slip and no penetration surface Multiple instances of the keyword permit individual nodal variables to be prescribed using independent load curves and scale factors 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 555 BOUNDARY PRESCRIBED CFD SET 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 6 set of nodes is given prescribed velocity the 6 x direction according to a specified vel time curve which is scaled BOUNDARY PRESCRIBED CFD SET Sie ee Din wen Diane Brenn Dee WA shroud ritu Decisis DEN an Ob ER Daran Laan ves 5 nsid dof lcid sf 4 101 8 2 0 5 5 nsid 4 nodal set ID number requires a SET NODE option 5 dof 101 x velocity is prescribed 5 lcid 8 velocity follows load curve 8 requires a DEFINE CURVE 5 sf 2 0 velocity specified by load curve is scaled 2 0 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 3 30 BOUNDARY LS DYNA Version 960 BOUNDARY BOUNDARY PRESCRIBED MOTION OPTION Available options include NODE SET RIGID RIGID LOCAL Purpose Define an imposed nodal motion velocity acceleration or displacement on a node or a set of nodes Also veloc
573. tity coefficient gj CAL3D MADYMO plane or ellipse number for coupled analysis see Appendix F G2 Entity coefficient g2 see remarks below G3 Entity coefficient g3 see remarks below G4 Entity coefficient g4 see remarks below G5 Entity coefficient g5 see remarks below G6 Entity coefficient go see remarks below G7 Entity coefficient g7 see remarks below Remarks Figures 6 4a and 6 4b show the definitions of the geometric contact entities The relationships between the entity coefficients and the Figure 6 4a and 6 4b variables are as follows please note that Px Py P is a position vector and that Qx Qy Qz is a direction vector 1 gl Px g4 82 85 g3 Pz g6 Qz g7 L If automatic generation is used a square plane of length L on each edge is generated which represents the infinite plane If generation is inactive then g7 may be ignored LS DYNA Version 960 6 43 CONTACT CONTACT GEOTYP 2 gl Px g4 r g2 Py g3 Pz 3 gl Px g4 g2 85 g3 Pz g6 Qz 27 r If automatic generation is used a cylinder of length 4 Qy Oz and radius is generated which represents the infinite cylinder GEOTYP 4 gl Px g4 a g2 Py g5 b g3 Pz g6 c g7 n order of the ellipsoid GEOTYP 5 gl Radius of torus g2 r g3 number of elements along minor circumference g4 number of elements along major circumference GEOTYP 8 gl Blank thicknes
574. to BNEND are added to the set These sets are generated after all input is read so that gaps in the element numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not element ID s OPTION Option for GENERAL See table below LS DYNA Version 960 24 27 SET SET VARIABLE DESCRIPTION ET B Specified entity Each card must have the option specified See table below OPTION ENTITY define up to 7 FUNCTION POEM EMEN All thick shell elements will be included in the set el e2 e3 e4 e5 e6 e7 Elements el e2 e3 will be included DELEM el e2 e3 e4 e5 e6 e7 Elements el e2 e3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 will be included DPART pl p2 p3 p4 p5 p6 p7 Elements of parts pl p2 p3 previously added will be excluded bl b2 b3 b4 b5 b6 b7 Elements inside boxes bl b2 will be included DBOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes b1 b2 previously added will be excluded 24 28 SET LS DYNA Version 960 TERMINATION The keyword provides an alternative way of stopping the calculation before the termination time is reached The termination time is specified on the CONTROL_ TERMINATION input and will terminate the calculation whether or not the options available in this section are active Different types of termination may be
575. to exceed 25 C1 CN Up to 25 constants for the user subroutine 1 4 AIRBAG LS DYNA Version 960 AIRBAG B LS DYNA Sensor Input RBID lt 0 Define three cards which provide the input parameters for the built in sensor subroutine Acceleration Velocity Displacement Activation 4 5 LS DYNA Version 960 1 5 AIRBAG AIRBAG VARIABLE AX AY AMAG TDUR DVX DVY DVZ DVMAG UZ UMAG 1 6 AIRBAG DESCRIPTION Acceleration level in local x direction to activate inflator The absolute value of the x acceleration is used EQ 0 inactive Acceleration level in local y direction to activate inflator The absolute value of the y acceleration is used EQ 0 inactive Acceleration level in local z direction to activate inflator The absolute value of the z acceleration is used EQ 0 inactive Acceleration magnitude required to activate inflator EQ 0 inactive Time duration acceleration must be exceeded before the inflator activates This is the cummulative time from the beginning of the calculation i e it is not continuous Velocity change in local x direction to activate the inflator The absolute value of the velocity change is used EQ 0 inactive Velocity change in local y direction to activate the inflator The absolute value of the velocity change is used EQ 0 inactive Velocity change in local z direction to activate the inflator The absolute value of the ve
576. toplastic constitutive models A discrete Kirchhoff triangular shell element DKT for explicit analysis with three in plane integration points is flagged as a type 17 shell element This element has much better bending behavior than the CO triangular element A discrete Kirchhoff linear triangular and quadrilaterial shell element is available as a type 18 shell This shell is for extracting normal modes and static analysis A CO linear 4 node quadrilaterial shell element is implemented as element type 20 with drilling stiffness for normal modes and static analysis An assumed strain linear brick element is avaiable for normal modes and statics The fully integrated thick shell element has been extended for use in implicit calculations Version 960 1 9 INTRODUCTION INTRODUCTION A fully integrated thick shell element based on an assumed strain formulation is now available This element uses a full 3D constitutive model which includes the normal stress component and therefore does not use the plane stress assumption The 4 node constant strain tetrahedron element has been extended for use in implicit calculations Relative damping between parts is available see DAMPING_RELATIVE SMP only Preload forces are can be input for the discrete beam elements Objective stress updates are implemented for the fully integrated brick shell element Acceleration time histories can be prescribed for rigid bodies Prescribed motion for nodal rigid bodies
577. tresses 1 42 AIRBAG LS DYNA Version 960 AIRBAG Define the follow card if and only if the option BIRTH is specified in the keyword 1 2 3 4 5 6 7 8 Card Format 18 3 16 0 Card 2 1 2 3 4 5 6 7 8 9 10 Type Default Remarks VARIABLE DESCRIPTION BIRTH Time at which the reference geometry activates default 0 0 NID Node number X X coordinate Y y coordinate Z z coordinate LS DYNA Version 960 1 43 AIRBAG AIRBAG 1 44 AIRBAG LS DYNA Version 960 ALE ALE The keyword ALE provides a way of defining input data pertaining to the Arbitrary nn capability The keyword control cards in this section are defined in alphabetical ALE MULTI MATERIAL GROUP ALE REFERENCE SYSTEM CURVE ALE REFERENCE SYSTEM GROUP ALE REFERENCE SYSTEM NODE ALE REFERENCE SYSTEM SWITCH ALE SMOOTHING For other input information related to the ALE capability see keywords CONTROL ALE INITIAL VOID and SECTION SOLID ALE LS DYNA Version 960 2 1 ALE ALE ALE MULTI MATERIAL GROUP Purpose The following input defines the PART ID s of each multi material group Elements containing materials of the same group are treated as single material elements Currently this option allows up to three 3 different material eoups to be mixed within the same element For each group define the following cards NOTE THE TOTAL NUMBER OF GROUPS MUST BE LESS THAN OR EQUAL TO THREE Card Format Remarks V
578. ts Gravity body load Point load Pressure load Thermal load Load curves Constrained nodes Welds Rivet Defaults ASCII time history files Binary plot time history and restart files Items in time history blocks Nodes for nodal reaction output Termination time Termination cycle CPU termination Degree of freedom 1 20 INTRODUCTION BOUNDARY_SPC_Option LOAD BODY Option LOAD NODE Option LOAD SEGMENT Option LOAD SHELL Option LOAD THERMAL Option DEFINE CURVE CONSTRAINED NODE SET CONSTRAINED GENERALIZED WELD Option CONSTRAINED SPOT WELD CONSTRAINED RIVET CONTROL OUTPUT DATABASE Option DATABASE BINARY DATABASE HISTORY Option DATABASE NODAL FORCE GROUP CONTROL TERMINATION CONTROL TERMINATION CONTROL CPU TERMINATION NODE LS DYNA Version 960 INTRODUCTION MATERIAL MODELS Some of the material models presently implemented are elastic orthotropic elastic kinematic isotropic plasticity Krieg and Key 1976 thermoelastoplastic Hallquist 1979 soil and crushable non crushable foam Key 1974 linear viscoelastic Key 1974 Blatz Ko rubber Key 1974 high explosive burn hydrodynamic without deviatoric stresses elastoplastic hydrodynamic temperature dependent elastoplastic Steinberg and Guinan 1978 isotropic elastoplastic isotropic elastoplastic with failure soil and crushable foam with failure Johnson Cook plasticity model Johnson and Cook 1
579. tude of the angular rotations are limited by the stop angles defined on Card 4 If the initial local coordinate axes do not coincide the angles and y will be initialized and torques will develop instantaneously based on the defined load curves yield moment curve elastic perfectly plastic behavior negative Rotation en stop angle positive stop angle Figure 5 16 Frictional behavior is modeled by a plasticity model Elastic behavior is obtained once the stop angles are reached The same elastic stiffness is used to simulate sticking situations 5 38 CONSTRAINED LS DYNA Version 960 CONSTRAINED Card 2 of 4 Required for FLEXION TORSION stiffness Card 2 1 2 3 4 5 6 LCIDAL LCIDG LCIDBT DLCIDAL DLCIDG DLCIDBT fiom fof VARIABLE DESCRIPTION LCIDAL Load curve ID for o moment versus rotation in radians See Figure 5 9 where it should be noted that 0 lt If zero the applied moment is set to zero See DEFINE CURVE LCIDG Load curve ID for y versus a scale factor which scales the bending moment due to the rotation This load curve should be defined in the interval lt lt If zero the scale factor defaults to 1 0 See DEFINE CURVE LCIDBT Load curve ID for B torsion moment versus twist in radians If zero the applied twist is set to zero See DEFINE CURVE DLCIDAL Load curve ID for o damping moment
580. ture rules in the SECTION_SHELL and SECTION_BEAM cards need to be specified as a negative number The absolute value of the negative number refers to user defined integration rule number Positive rule numbers refer to the built in quadrature rules within LS DYNA3D Interface definitions are used to define surfaces nodal lines and nodal points for which the displacement and velocity time histories are saved at some user specified frequency This data may then used in subsequent analyses as an interface ID in the INTERFACE_LINKING_DISCRETE_ NODE as master nodes in INTERFACE_LINKING_SEGMENT as master segments and in 1 16 INTRODUCTION LS DYNA Version 960 INTRODUCTION INTERFACE_LINKING_EDGE as the master edge for a series of nodes This capability is especially useful for studying the detailed response of a small member in a large structure For the first analysis the member of interest need only be discretized sufficiently that the displacements and velocities on its boundaries are reasonably accurate After the first analysis is completed the member can be finely discretized in the region bounded by the interfaces Finally the second analysis is performed to obtain highly detailed information in the local region of interest When beginning the first analysis specify a name for the interface segment file using the Z parameter on the LS DYNA3D execution line When starting the second analysis the name of the interfac
581. ue of the maximum principal strain is exceeded the scale factor for flow SF is active FSL If the strain ratio Ennion 15 exceeded the scale factor for flow workpiece i SF is active LS DYNA Version 960 10 13 DEFINE DEFINE VARIABLE DESCRIPTION TSL Thickness strain limit If the through thickness strain is exceeded the scale factor for thickening ST is active SFF Scale factor for the flow limit diagram SF Default 1 0 SFT Scale factor for thickening ST Default 1 0 BIAS Bias for combined flow and thickening S 1 lt 8 lt 1 Remarks The scale factor for the load curve ordinate value is updated as gn Sn load curve load curve S nal where lt 15 equal to SF if the strain ratio is exceeded or to ST if the thickness strain limit is exceeded The bias value determines the final scale factor in the event that the thickness and flow limit diagram criteria both satisfied In this case the scale factor for the load curve is given by Za S SF EE S ST Generally SF is slightly less than unity and ST is slightly greater than unity so that S oadcurve changes insignificantly from time step to time step 10 14 DEFINE LS DYNA Version 960 DEFINE MAJOR STRAIN 20 MINOR STRAIN Figure 10 3 Flow limit diagram LS DYNA Version 960 10 15 DEFINE DEFINE DEFINE CURVE SMOOTH Purpose Define a smoothly varying curve using few parameters
582. ue will activate the contact thickness offsets in the contact algorithms where offsets apply The contact treatment with then be equivalent to the case where null shell elements are used to cover the brick elements The contact stiffness parameter below SLDSTF may also be used to override the default value SLDSTF Optional solid element stiffness A nonzero positive value overrides the bulk modulus taken from the material model referenced by the solid element LS DYNA Version 960 6 27 CONTACT CONTACT Optional Card C Reminder If Optional Card C is used then Optional Cards A and B must be defined Optional Cards A and B may be blank lines Optional 1 2 3 4 5 6 T 8 Card C Remarks VARIABLE DESCRIPTION IGAP Flag to improve implicit convergence behavior at the expense of creating some sticking if parts attempt to separate IMPLICIT ONLY EQ 1 apply method to improve convergence EQ 2 do not apply method DEFAULT IGNORE Ignore initial penetrations in the CONTACT AUTOMATIC options This option can also be specified for each interface The value defined here will be the default EQ 0 Take the default value from the fourth card of the CONTROL CONTACT input EQ 1 Allow initial penetrations to exist by tracking the initial penetrations EQ 2 Move nodes to eliminate initial penetrations in the model definition 6 28 CONTACT LS DYNA Version 960 1 CONTACT General Remarks on CONTACT TIED_NODES_TO_
583. ugh the rigid body time history option and MCOLENERGY LS DYNA Version 960 3 23 BOUNDARY BOUNDARY BOUNDARY NON REFLECTING Purpose Define a non reflecting boundary This option applies to continuum domains modeled with solid elements as indefinite domains are usually not modeled For geomechanical problems this option is important for limiting the size of the models Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT AD Default activation flag for dilatational waves on EQ 0 0 off NE 0 0 AS Default activation flag for shear waves on EQ 0 0 off NE 0 0 Remarks 1 Non reflecting boundaries defined with this keyword are only used with three dimensional solid elements Boundaries are defined as a collection of segments and segments are equivalent to element faces on the boundary Segments are defined by listing the corner nodes in either a clockwise or counterclockwise order 2 Non reflecting boundaries are used on the exterior boundaries of an analysis model of an infinite domain such as a half space to prevent artificial stress wave reflections generated at the model boundaries form reentering the model and contaminating the results Internally LS DYNA computes an impedance matching function for all non reflecting boundary segments based on an assumption of linear material behavior Thus the finite element mesh should be constructed so that all significant nonlinear be
584. ulations all of the beam element choices are implemented 2 For the truss element define the cross sectional area A only 3 local coordinate system rotates as the nodal points that define the beam rotate In some cases this may lead to unexpected results if the nodes undergo significant rotational motions In the definition of the local coordinate system using DEFINE COORDINATE SYSTEM NODES if the option to update the system each cycle is active then this updated system is used This latter technique seems to be more stable in some applications LS DYNA Version 960 23 5 SECTION SECTION 555555555555555555555555555555555555555555555555555555555555555555555555555555955 5 SECTION BEAM 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 2nd polar moment of area about beam axis irr 170 000 0 mm4 Define a Belytschko Schwer resultant beam elform 2 with the following properties This beam models the connection stiffening beams of a medium 6 size roadside sign 5 cross sectional area a 515 6 mm2 5 2nd moment of area about s axis iss 99 660 0 mm4 2nd moment of area about t axis iss 70 500 0 mm4 8 SECTION BEAM Sat eu Ze Dean Des De se eR EB 5 sid elform shrf qr irid est 2 5 5 iss itt irr sa 515 6 99660 0 70500 0 170000 0 5 SECTION BEAM TITLE Main beam member De Da Ze DDr DD De De aD si
585. unrealistically large thickness may result in a degradation in speed during the bucket sorts as well as nonphysical behavior The SHLTHK option on the CONTROL CONTACT card is ignored for these contact types 5 Two methods are used in LS DYNA for projecting the contact surface to account for shell thicknesses The choice of methods can influence the accuracy and cost of the calculation Segment based projection is used in contact types AIRBAG SINGLE SURFACE AUTOMATIC GENERAL AUTOMATIC NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE FORMING NODES TO SURFACE FORMING ONE WAY SURFACE TO SURFACE 6 30 CONTACT LS DYNA Version 960 CONTACT FORMING_SURFACE_TO_SURFACE The remaining contact types use nodal normal projections if projections are used The main advantage of nodal projections is that a continuous contact surface is obtained which is much more accurate in applications such as metal forming The disadvantages of nodal projections are the higher costs due to the nodal normal calculations difficulties in treating T intersections and other geometric complications and the need for consistent orientation of contact surface segments The contact type SINGLE_SURFACE uses nodal normal projections and consequently is slower than the alternatives 6 FORCE_TRANSDUCER_PENALTY FORCE_TRANSDUCER_CONSTRAINT This contact allows the total contact forces applied by all contacts to
586. ure brick element with an exact hourglass stiffness matrix has been implemented for implicit and explicit calculations Automatic file length determination for D3PLOT binary database is now implemented This insures that at least a single state is contained in each D3PLOT file and eliminates the problem with the states being split between files The dump files which can be very large can be placed in another directory by specifying d home user test d3dump on the execution line A print flag controls the output of data into the MATSUM and RBDOUT files by part ID s The option PRINT has been added as an option to the PART keyword Flag has been added to delete material data from the D3THDT file See DATABASE_ EXTENT_BINARY and column 25 of the 19th control card in the structured input After dynamic relaxation completes a file is written giving the displaced state which can be used for stress initialization in later runs Capabilities added during 1998 2000 in Version 960 Most new capabilities work on both the MPP and SMP versions however the capabilities that are implemented for the SMP version only which were not onsidered critical for this release are flagged below These SMP unique capabilities are being extended for MPP calculations and will be available in the near future The implicit capabilities for MPP require the development of a scalable eigenvalue solver which is under development for a later releas e of LS DYN
587. ure criterion 2 2 21 NFLS SFLS TBLCID Optional load curve number defining the resisting stress versus gap opening for the post failure response This can be used to model the failure of adhesives Remarks The failure attributes can be overridden segment by segment on the SET SEGMENT or SET_SHELL_option cards for the slave surface only as Al and A2 These variables do not apply to the master surface Both NFLS and SFLS must be defined If failure in only tension or shear is required then set the other failure stress to a large value 1 10 When used with shells contact segment normals are used to establish the tension direction as opposed to compression Compressive stress does not contribute to the failure equation After failure this contact option behaves as a surface to surface contact with no thickness offsets After failure no interface tension is possible LS DYNA Version 960 6 21 CONTACT CONTACT This Card is mandatory for the THERMAL option i e Reminder If Card 4 is required then it must go before this optional card Card 4 is required for certain contact types see earlier in this section for the list later in this section for details of Card 4 CONTACT THERMAL Optional 1 2 3 4 5 6 7 8 w fe fe fe fete fe TY pii s VARIABLE DESCRIPTION CF Thermal conductivity of fluid between the slide surfaces If a gap with
588. use default EQ 1 use FORM Element formulation when using IMFORM flag EQ 0 type 16 EQ 1 type 6 LS DYNA Version 960 7 49 CONTROL CONTROL Remarks IMFLAG DTO IMFORM NSBS IGS The default value 0 indicates a standard explicit analysis will be performed Using value 1 causes an entirely implicit analysis to be performed Value 2 is automatically activated when the keyword INTERFACE SPRINGBACK SEAMLESS is present causing the analysis type to switch when the termination time is reached After this switch the termination time is extended by NSBS DTO or reset to twice its original value if DTO 0 0 The implicit simulation then proceeds until the new termination time is reached This parameter selects the initial time step size for the implicit phase of a simulation In a springback simulation the default initial time step size is the termination time from the explicit forming phase of the simulation The step size may be adjusted during a multiple step simulation if the automatic time step size control feature is active The default Belytschko Tsay shell element works well for forming analysis but can perform poorly for springback analysis This element formulation switching flag causes the more stable fully integrated shell elements to be used for the springback phase Adaptive mesh must be activated when using element formulation switching The default springback analysis is nonlinear single step When the autom
589. used A JWL equation of state defines the pressure in the unreacted explosive as ae wee cvr e where Ve and Te are the relative volume and temperature respectively of the unreacted explosive Another JWL equation of state defines the pressure in the reaction products as u xplV xp2Vp gTp be t yo eye where Vp and Tp are the relative volume and temperature respectively of the reaction products As the chemical reaction converts unreacted explosive to reaction products these JWL equations of state are used to calculate the mixture of unreacted explosive and reaction products defined by the fraction reacted F F O implies no reaction F 1 implies complete reaction The temperatures and pressures are assumed to be equal Te Tp pe pp and the relative volumes are additive i e V 1 F Ve Vp The chemical reaction rate for conversion of unreacted explosive to reaction products consists of three physically realistic terms an ignition term in which a small amount of explosive reacts soon after the shock wave compresses it a slow growth of reaction as this initial reaction spreads and a rapid completion of reaction at high pressure and temperature The form of the reaction rate equation is freq 1 F a Ve cerit Ignition t growl 1 p Growth grow2 1 F F p Completion The ignition rate is set equal to zero when
590. using a fatal error EQ 2 Discrete spring and damper elements are added to the D3PLOT or D3PART database where they are displayed as beam elements similar to option 0 In this option the element resultant force is written to its first database position allowing beam axial forces and spring resultant forces to be plotted at the same time This can be useful during some post processing applications NPLTC DT ENDTIME NPLTC applies to D3PLOT and D3PART only This overrides the DT specified in the first field PSETID SET PART ID for D3PART only 9 8 DATABASE LS DYNA Version 960 DATABASE ISTATS Set the level of statistics to collect This applies to D3MEAN only and is also restricted to the incompressible CFD solver variables EQ 0 don t collect any statistics default EQ 1 generate mean quantities EQ 2 generate second moments in addition to the mean quantities EQ 3 generate higher order moments in addition to all other moments TSTART Set the simulation time at which collection of the time averaged statistics will begin D3MEAN only TSTART 0 0 is the default IAVG Set the interval to write out the time averaged statistics D3MEAN only The time averaged statistics are re initialized and collection of new statistics starts after the time averaged data is written to the database EQ 0 IAVG 100 default Remarks 1 When positive this option creates the D3MEAN binary database containing the mean field values a
591. ward normal vectors should point into the fluid media Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT WETDRY Wet surface flag 0 dry no coupling EQ 1 wet coupled with USA NBEAM The number of nodes touched by USA Surface of Revolution SOR elements It is not necessary that the LS DYNA model has beams where USA has beams i e SOR elements merely that the LS DYNA model has nodes to receive the forces that USA will return Remarks The wet surface of 3 and 4 noded USA General boundary elements is defined in LS DYNA with a segment set of 4 noded surface segments where the fourth node can duplicate the third node to form a triangle The segment normals should be directed into the USA fluid If USA overlays are going to be used to reduce the size of the DAA matrices the user should nonetheless define the wet surface here as if no overlay were being used If Surface of Revolution elements SORs are being used in USA then NBEAM should be non zero on one and only one card in this section When running a coupled problem with USA the procedure involves several steps First LS DYNA is executed to create a LS DYNA dump file d3dump and a linking file strnam which contains the nodal grid point data and wet segment connectivity data for the FLUMAS processor and the dof equation table strutural mass vector for the AUGMAT processor Dyna pre is denoted grdnam in F
592. with this option OPTIONS specifies that the first card to read defines the title and ID number of contact interface and takes the single option TITLE Note OPTION2 and OPTION3 may appear in any order At present the contact ID number and title are ignored by LS DYNA but are included for extension in the near future The title card is picked up by some of the peripheral LS DYNA codes to aid in post processing Single surface contact in two dimensions is accomplished by the AUTOMATIC SURFACE TO SURFACE option when the master surface part set is set to zero The SINGLE SURFACE option in version 940 has been removed 6 56 CONTACT LS DYNA Version 960 CONTACT Read the following card here if and only if the option TITLE is specified Optional For all options except the AUTOMATIC options define the following two cards Card 1 Format Card 1 2 3 4 5 6 7 8 Card 2 Format Card 2 1 2 3 4 5 6 7 8 EXT PAS THETAI LS DYNA Version 960 6 57 CONTACT CONTACT For the PENALTY_FRICTION option define the following additional card Card 3 1 2 3 4 5 6 7 8 ida i Mid TO polo VARIABLE DESCRIPTION SSID Nodal set ID for the slave nodes see SET NODE The slave surface must be to the left of the master surface MSID Nodal set ID for the master nodes see SET NODE EXT PAS Slideline extension bypass option EQ 0 extensions are use EQ 1 extensions are not used THETAI Angle in degrees of slideline e
593. word LS DYNA Version 960 19 3 LOAD LOAD LOAD_BLAST Purpose Define an airblast function for the application of pressure loads due to explosives in conventional weapons The implementation is based on a report by Randers Pehrson and Bannister 1997 where it is mentioned that this model is adequate for use in engineering studies of vehicle responses due to the blast from land mines This option determines the pressue values when used in conjuntion with the keywords LOAD_SEGMENT LOAD_SEGMENT_SET or LOAD_ SHELL Card Format Card 1 1 2 3 4 5 6 7 8 ZIEIEIEICHCICCEN 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION WGT Equivalent mass of TNT XBO x coordinate of point of explosion YBO y coordinate of point of explosion ZBO z coordinate of point of explosion TBO Time zero of explosion 19 4 LOAD LS DYNA Version 960 LOAD VARIABLE DESCRIPTION IUNIT Unit conversion flag EQ 1 feet pounds seconds psi EQ 2 meters kilograms seconds Pascals default EQ 3 inch dozens of slugs seconds psi EQ 4 centimeters grams microseconds Megabars EQ 5 user conversions will be supplied see Card 2 ISURF Type of burst EQ 1 surface burst hemispherical charge situated on the surface EQ 2 air burst spherical charge at least one charge diameter away from the surface default CFM Conversion factor pounds per LS DYNA mass unit CFL Conversion factor feet per LS DYNA len
594. xation Tank volume which is required only for the tank pressure versus time curve LCMT Load curve for time rate of change of temperature dT dt versus time Initial airbag temperature Optional generally not defined Vent orifice coefficient which applies to exit hole Set to zero if LCC23 is defined below Load curve number defining the vent orifice coefficient which applies to exit hole as a function of time A nonzero value for C23 overrides LCC23 Vent orifice area which applies to exit hole Set to zero if LCA23 is defined below Load curve number defining the vent orifice area which applies to exit hole as a function of absolute pressure A nonzero value for A23 overrides LCA23 Orifice coefficient for leakage fabric porosity Set to zero if LCCP23 is defined below Load curve number defining the orifice coefficient for leakage fabric porosity as a function of time A nonzero value for CP23 overrides LCCP23 Area for leakage fabric porosity Load curve number defining the area for leakage fabric porosity as a function of absolute pressure A nonzero value for AP23 overrides LCAP23 Ambient pressure LS DYNA Version 960 VARIABLE RO GC LCEFR POVER PPOP OPT KNKDN IOC IOA IVOL IRO LCBF TEXT A B LS DYNA Version 960 AIRBAG DESCRIPTION Ambient density Gravitational conversion constant mandatory no default If consistent units are being used fo
595. xt card terminates the input 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 1 BIEND B2BEG B2END B3BEG B3END B4BEG B4END 24 2 SET LS DYNA Version 960 SET Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options ALL ELEM DELEM PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID First beam element K2 Second beam element KNUM Last beam element BNBEG First beam element ID in block N BNEND Last beam element ID in block N All defined ID s between and including BNBEG to BNEND are added to the set These sets are generated after all input is read so that gaps in the element numbering are not a problem BNBEG and BNEND may simply be limits on the ID s and not element ID s OPTION Option for GENERAL See table below 1 7 Specified entity Each card must have the option specified See table below LS DYNA Version 960 24 3 SET SET OPTION ENTITY define up to 7 FUNCTION ALL 5 All beam elements will be included in the set el e2 e3 e4 e5 e7 Elements el e2 e3 will be included DELEM el e2 e3 e4 e5 e7 Elements el e2 e3 previously added will be excluded pl p2 p3 p4 p5 p6 p7 Elements of parts p1 p2 p3 will be included DPART pl p2 p3 p4 p5 p6 p7 El
596. xtension at first master node EQ 0 extension remains tangent to first master segment THETA2 Angle in degrees of slideline extension at last master node EQ 0 extension remains tangent to first master segment TOL_IG Tolerance for determing initial gaps EQ 0 0 default set to 0 001 PEN Scale factor or penalty EQ 0 0 default set to 0 10 FRIC Coefficient of friction FRIC_L Coefficient of friction at low velocity FRIC_H Coefficient of friction at high velocity FRIC_S Friction factor for shear 6 58 CONTACT LS DYNA Version 960 CONTACT For the AUTOMATIC options define the following two cards Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 This Card is mandatory for the THERMAL option i e CONTACT_ AUTOMATIC THERMAL Optional 1 2 3 4 5 6 7 8 LS DYNA Version 960 6 59 CONTACT CONTACT VARIABLE PSIDS PSIDM SFACT FREQ FS FD DC MEMBS TBIRTH TDEATH SOS SOM NDS 6 60 CONTACT DESCRIPTION Part set ID to define the slave surface see SET_PART Part set ID to define the master surface see SET PART Do not define if single surface contact is desired Scale factor for the penalty force stiffness Search frequency The number of timesteps between bucket sorts EQ 0 default set to 50 Static coefficient of friction The frictional coefficient is assumed to be dependent on the relative velocity v e of the surfaces in contact according to the relation
597. y request and then read in the desired memory size This option is necessary if the default value is insufficient memory and termination occurs as a result Occasionally the default value is too large for execution and this option can be used to lower the default size Memory can also be specified on the KEYWORD card 1 28 INTRODUCTION LS DYNA Version 960 INTRODUCTION File Organization stress restart interface vda geometry initialization segment M R V CAL3D TOPAZ3D input QUT CE file Y T LS DYNA printer file graphics restart dump O d3hsp G d3plot messag time histories runrsf f d3thdt input echo Interne interface segment save E S Z ASCII Database dynamic relaxation B d3drfl Figure 1 3 LS DYNA Version 960 1 29 INTRODUCTION INTRODUCTION File names must be unique The interface force file is created only if it is specified on the execution line S iff On large problems the default file sizes may not be large enough for a single file to hold either a restart dump or a plot state Then the file size may be increased by specifying the file size on the execute line using X scl The default file size holds seven times one million octal word 262144 or 1835008 words If the core required by LS DYNA requires more space it is recommended that the be increased appropriately Using C cpu defines the maximum cpu usage allowed that if exceeded will cause LS DYNA to
598. y a punch a holder is used to hold the blank on its sides All shells on the holder are given pressure boundary condition to clamp down on the blank The pressure follows load curve 3 but is scaled by 1 so that it applies the load in the correct direction The load starts at zero but quickly rises to 5 MPa after 0 001 sec Units of this model are in ton mm s N MPa N mm LOAD SHELL ELEMENT SiS edie Bek eas Qed DE S oS aed ivi De Ow ip s s mede 5 eid lcid sf at 30001 3 1 00 00 0 0 30002 3 1 00 00 0 0 30003 3 1 00 00 0 0 30004 3 1 00 00 0 0 30005 3 1 00 00 0 0 30006 3 1 00 00 0 0 30007 3 1 00 00 0 0 5 Note Just a subset of all the shell elements of the holder is shown above 5 in practice this list contained 448 shell element id s DEFINE CURVE 5 lcid sidr scla sclo offa offo 3 5 abscissa ordinate 0 000 0 0 0 001 5 0 0 150 5 0 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 LS DYNA Version 960 19 29 LOAD LOAD LOAD_SSA Purpose The Sub Sea Analysis capability allows a simple way of loading the structure to account for the effects of the primary explosion and the subsequent bubble oscillations Define one card Card 1 Define two cards for each explosive charge This input is terminated by the next keyword card Card 1 1 6 7 8 19 30 LOAD LS DYNA Versio
599. y added will be excluded b1 b2 b3 b4 b5 b6 b7 Elements inside boxes bl b2 will be included DBOX bl b2 b3 b4 b5 b6 b7 Elements inside boxes b1 b2 previously added will be excluded LS DYNA Version 960 24 25 SET SET SET TSHELL OPTION Available options include BLANK GENERATE GENERAL The last option GENERATE will generate a block of thick shell element ID s between a starting ID and an ending ID An arbitrary number of blocks can be specified to define the set Purpose Define a set of thick shell elements Card Format 1 2 3 4 5 6 7 8 Cards 2 3 4 OPTION none The next card terminates the input 1 2 3 4 5 6 T 8 24 26 SET LS DYNA Version 960 SET Cards 2 3 4 OPTION GENERATE The next card terminates the input 1 2 3 4 5 6 7 8 BIBEG BIEND B2BEG B2END B3BEG B3END B4BEG B4END Cards 2 3 4 OPTION GENERAL The next card terminates the input This set is a combination of a series of options ALL ELEM DELEM PART DPART BOX and DBOX 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Set ID All tshell sets should have a unique set ID First thick shell element ID K2 Second thick shell element ID K8 Eighth thick shell element ID BNBEG First thick shell element ID in block N BNEND Last thick shell element ID in block N All defined ID s between and including BNBEG
600. y response 3 Body force loads due to the angular velocity about an axis are calculated with respect to the deformed configuration and act radially outward from the axis of rotation Torsional effects LS DYNA Version 960 19 7 LOAD LOAD which arise from changes in angular velocity are neglected with this option The angular velocity is assumed to have the units of radians per unit time 4 body force density is given at a point P of the body by b p x xr where p is the mass density is the angular velocity vector and r is a position vector from the origin to point P Although the angular velocity may vary with time the effects of angular acceleration are not included 5 Angular velocities are useful for studying transient deformation of spinning three dimensional objects Typical applications have included stress initialization during dynamic relaxation where the initial rotational velocities are assigned at the completion of the initialization and this option ceases to be active 19 8 LOAD LS DYNA Version 960 LOAD 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 555 LOAD BODY 7 5 55555555555555555555555555555555555555555555555555555555555555555555555555555555 5 Add gravity such that it acts in the negative Z direction Use units of mm ms2 Since gravity is constant the load curve is set as a constant equal to 1 If the simulation is to exceed 1000 ms then
601. y stiffness value option For default calculation of the penalty value please refer to the Theoretical Manual EQ 0 the default 1s set to 1 EQ 1 minimum of master segment and slave node default for most contact types 7 30 CONTROL LS DYNA Version 960 CONTROL VARIABLE DESCRIPTION EQ 2 use master segment stiffness old way EQ 3 use slave node value EQ 4 use slave node value area or mass weighted EQ 5 same as 4 but inversely proportional to the shell thickness This may require special scaling and is not generally recommended Options 4 and 5 are recommended for metalforming calculations THKCHG Shell thickness changes considered in single surface contact EQ 0 no consideration default EQ 1 shell thickness changes are included ORIEN Optional automatic reorientation of contact interface segments during initialization EQ 0 default is set to 1 EQ 1 active for automated part input only Contact surfaces are given by PART definitions EQ 2 active for manual segment and automated part input EQ 3 inactive ENMASS Treatment of the mass of eroded nodes in contact This option effects all contact types where nodes are removed after surrounding elements fail Generally the removal of eroded nodes makes the calculation more stable however in problems where erosion is important the reduction of mass will lead to incorrect results 0 eroding nodes are removed from the calculation EQ 1 eroding
602. yword serves two purposes 1 Relates part ID to SECTION MATERIAL EOS and HOURGLASS sections 2 Optionally in the case of a rigid material rigid body inertia properties and initial conditions can be specified Deformable material repositioning data can also be specified in this section if the reposition option is invoked on the PART card i e PART_REPOSITION RIGIDWALL Rigid wall definitions have been divided into two separate sections PLANAR and GEOMETRIC Planar walls can be either stationary or moving in translational motion with mass and initial velocity The planar wall can be either finite or infinite Geometric walls can be planar as well as have the geometric shapes such as rectangular prism cylindrical prism and sphere By default these walls are stationary unless the option MOTION is invoked for either prescribed translational velocity or displacement Unlike the planar walls the motion of the geometric wall is governed by a load curve Multiple geometric walls can be defined to model combinations of geometric shapes available For example a wall defined with the CYLINDER option can be combined with two walls defined with the _SPHERICAL option to model hemispherical surface caps on the two ends of a cylinder Contact entities are also analytical surfaces but have the significant advantage that the motion can be influenced by the contact to other bodies or prescribed with six full degrees of freedom LS DYNA Version 960 1 1
603. ze of the small elements generated during trimming The default tolerance left produces large elements Using a tolerance of 0 01 right allows smaller elements and more detail in the trim line 10 20 DEFINE LS DYNA Version 960 DEFINE DEFINE SD ORIENTATION Purpose Define orientation vectors for discrete springs and dampers These orientation vectors are optional for this element class Four alternative options are possible With the first two options IOP 0 or 1 the vector is defined by coordinates and is fixed permanently in space The third and fourth optiona orients the vector based on the motion of two nodes so that the direction can change as the line defined by the nodes rotates Card Format 1 2 3 4 5 6 7 8 eE EE E meee eee VARIABLE DESCRIPTION VID Orientation vector ID A unique ID number must be used IOP Option EQ 0 deflections rotations are measured and forces moments applied along the following orientation vector EQ 1 deflections rotations are measured and forces moments applied along the axis between the two spring damper nodes projected onto the plane normal to the following orientation vector EQ 2 deflections rotations are measured and forces moments applied along a vector defined by the following two nodes EQ 3 deflections rotations are measured and forces moments applied along the axis between the two spring damper nodes projected onto the plane normal to the a vector def

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