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LS-DYNA3D User's Manual

1. where is the strain rate 6 6 II For complete generality a load curve LCSR to scale the yield stress may be input instead In this curve the scale factor versus strain rate is defined 19 206 MAT LS DYNA3D Version 936 MAT MAT ORTHOTROPIC VISCOELASTIC This is Material Type 86 It allows the definition of an orthotropic material with a viscoelastic part This model applies to shell elements Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 Card 3 EE Card 4 LS DYNA3D Version 936 19 207 MAT MAT Card 5 Variable Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density EA Young s Modulus Ea EB Young s Modulus Ep EC Young s Modulus Ec VF Volume fraction of viscoelastic material K Elastic bulk modulus GO Go short time shear modulus GINF long time shear modulus BETA B decay constant PRBA Poisson s ratio Vba PRCA Poisson s ratio PRCB Poisson s ratio GAB Shear modulus Gab GBC Shear modulus Gpe GCA Shear modulus Gea 19 208 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION AOPT Material axes option see Figure 19 1 EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0
2. n n tu max where P mix LS DYNA3D Version 936 12 27 EOS EOS 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 Ppc V Poe This representation suggests that for a fixed Vmin the partially crushed curve will U max 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 au oP The slope 3u for the partially crushed curve is obtained by differentiation as u ap e 1 2 oP 1 Simplifying 1 where 1 E The bulk sound speed is determined from the slope of the completely crushed curve at the current pressure to avoid instabilities in the time step 12 28 EOS LS DYNA3D Version 936 EOS 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 DYNA3D Version 936 12 29 EOS HOURGLASS HOURGLASS
3. 9 Cold compression energy coefficients optional Users who have an interest in this model are encouraged to study the paper by Steinberg and Guinan which provides the theoretical basis Another useful reference is the KOVEC user s manual In terms of the foregoing input parameters we define the shear modulus G before the material melts as G Gy 14 bpy 3 i e d 3R where p is the pressure V is the relative volume is the cold compression energy x 900 R exp ax X p a x 1 V and is the melting energy which is in terms of the melting temperature T x Tno exp 2ax Tp x m0 and the melting temperature at Tmo In the above equation R is defined by ea FP A where R is the gas constant and A is the atomic weight If R is not defined LS DYNA3D computes it with R in the cm gram microsecond system of units 19 34 MAT LS DYNA3D Version 936 MAT The yield strength oy is given by _ _ 5h eov 3 i55 300 if Em exceeds Ej Here og 16 given by 9 Op e vi er where y is the initial plastic strain Whenever 69 exceeds Om 00 is set equal to Om After the materials melts oy and G are set to one half their initial value If the coefficients ECO EC9 are not defined above LS DYNA3D will fit the cold compression energy to a ten term polynomial expansion eit
4. is adequate IBQ Bulk viscosity type See remark 3 below EQ 1 standard LS DYNA3D Q2 Quadratic bulk viscosity coefficient Q1 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 1 Viscous hourglass control is recommended for problems deforming with high velocities Stiffness control is preferable for lower velocities For solid elements the exact integration provides some advantage for highly distorted elements 2 For automotive crash the stiffness form of the hourglass control with a coefficient of 0 05 is preferred by many users 2 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 the viscous stress can be significant It is not advisable to reduce it by more than an order of magnitude 4 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
5. eere nennen 4 42 CONTACT roe 5 1 CONTACT OPTIONI OPTION2 2 22 5 1 on dois oi And Doin ea AA 5 19 CONJAGQTSTDC he tele eh d hin e 5 27 UU 6 1 CONTROL ADAPTIVE ces ttt rte ederet deret dp iei e ESE 6 2 CONTROL AEB a e ete a tete e e e tete tee ete tete E 6 4 CONTROL BULK VISCOSITY nte e tette roger tes 6 6 CONTROL CONTAC 3 5 nieht ether p ub dh TA T 6 7 ERES e 6 11 FCONTROE CPU terit iet eet i reete gere prt ey ert Pot ee reste pet ertt 6 13 11 LS DYNA3D Version 936 TABLE OF CONTENTS CONTROL DYNAMIC RELAXATION ente re eim ee Pi eerta 6 14 CONTROL ENERGY etin i E ROI EB iii eee 6 16 CONTROL HOURGL ASS 1 2 m ire e Re e 6 17 CONTROL QU TPU Toone i eee tti t ete erepti Feet pep te espere Rs 6 18 CONTROL PARALDLEL B ee eR RC t te eps 6 19 CONTROL SHEL ti eens ii Cro P Eee Ss 6 20 CONTROL SOLUTION rie Cas 6 22 CONTROE STRUCTURED tete ete OR e e EE etae iret 6 23 CONTROL SUBCYGLE 5 nOn 6 24 CONTROL TERMINATION 6 25 CONTROL
6. LS DYNA3D Version 936 MAT and the heat generation coefficient is LS DYNA3D Version 936 19 131 MAT MAT MAT BAMMAN DAMAGE This is Material Type 52 This is an extension of model 51 which includes the modeling of damage See Bamman et al 1990 Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 Card 4 19 132 MAT LS DYNA3D Version 936 MAT Card 5 Variable Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus psi PR Poisson s ratio T Initial temperature 9R HC Heat generation coefficient PR psi Cl Psi 2 R C3 Psi C4 R C5 1 C6 C7 psi C8 9 Psi C10 C11 I psi s C12 R LS DYNA3D Version 936 19 133 MAT MAT VARIABLE DESCRIPTION C13 l psi 14 5 C16 oR C17 l psi s C18 Al initial value of internal state variable 1 A2 initial value of internal state variable 2 A3 initial value of internal state variable 3 4 04 initial value of internal state variable 4 5 Qs initial value of internal state variable 5 A6 initial value of internal state variable 6 N Exponent in damage evolution DO Initial damage porosity The evolution of the damage parameter is defined by Bammann et al 1990 B i in which _ I 2QN 1 p Ced where p is the pressure and is the effective stress 19 134
7. SPRING MAXWELL This material allows to simulate a three Parameter Maxwell Viscoelastic translational or rotational spring Optionally a cutoff time with a remaining constant force moment can be defined Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen KO Ko short time stiffness KI Koo long time stiffness BETA Decay parameter TC Cut off time After this time a constant force moment is transmitted FC Force moment after cutoff time COPT Time implementation option EQ 0 incremental time change NE 0 continuous time change The time varying stiffness K t may be described in terms of the input parameters as K t Kg Ke P This equation was implemented by Schwer 60 as either a continuous function of time or incrementally following the approach of Herrmann and Peterson 61 The continous function of time implementation has the disadvantage of the energy absorber s resistance decaying with increasing time even without deformation The advantage of the incremental implementation is that LS DYNA3D Version 936 19 225 MAT MAT an energy absorber must undergo some deformation before its resistance decays 1 there is no decay until impact even in delayed impacts The disadvantage of the incremental implementation is that very rapid decreases in resistance cannot be easily matched 19 226 MAT LS DYNA3D Version
8. coefficients for defining heat capacity and temperature dependency of heat capacity G2 G3 G4 The Armstrong Zerilli Material Model express the yield stress as follows For FCC metals LS DYNA3D Version 936 ener cp 19 163 MAT MAT and for BCC metals encor Paus n where BT B3T The relationship between heat capacity and temperature may be characterized by a cubic polynomial equation as follows C Gj GT GST G4T 19 164 MAT LS DYNA3D Version 936 MAT MAT LINEAR ELASTIC DISCRETE BEAM This is Material Type 66 This material model is defined for simulating the effects of a linear elastic zero length beams by using six springs each acting about one of the six local degrees of freedom Translational rotational stiffness and viscous damping effects are considered for a local cartesian system see notes below Applications for this element include the modeling of joint stiffnesses Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density see also volume in the SECTION BEAM definition TKR Translational stiffness about local r axis see notes below TKS Translational stiffness about local s axis TKT Translational stiffness about local t axis RKR Rotational stiffness about the local r axis RKS Rotational stiffness about the local s axis RKT Rotational stiffness about t
9. LS DYNA3D Version 936 12 21 EOS EOS VARIABLE A XP2 FRER RI R2 R3 R5 R6 FMXIG FREQ GROWI EM ARI ES CVP CVR EETAL CCRIT ENQ TMPO GROW2 12 22 EOS DESCRIPTION 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 15 term Exponent on 1 F 15 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 LS DYNA3D Version 936 EOS VARIABLE DESCRIPTION AR2 Exponent 214 term ES2 Exponent on 1 214 term EN Pressure Exponent 214 term FMXGR Maximum for 13t term FMNGR Minimum for 214 term 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 conduc
10. nn 14 1 INCLUDE 5 tet o Ub o i eo ER DRE PR 14 1 15 1 INITIAL DETONATION co innr eie dune rete te ee ener 15 2 INETTAL MOMENTUM 5 qe eve 15 4 SINETTAL STRESS BEAM 5 erinnert er eet ette eret rete oe rede etes 15 5 MINTTIAL STRESS SHELE terrore tiet 15 7 INITIAL ZS TRESS SOLID 2 a nd o ERRORS dept 15 9 INITIAL TEMPERATURE OPTION rnenso sene eet torret tet dene hee ee o veiut 15 11 INITIA L VELOCITY iet hee ete E t eee E exe ente 15 12 INITIAL VELOCITY NODB iier ehe 15 14 INITIAL VELOCITY GENERATION eere eren nnne nnne nnne enne enne 15 15 UNiO 16 1 INTEGRATION BEXM btt 16 1 INTEGRATION SHED 16 6 FINTEREFACE cscccssssssssrsscssesssesssesssessscssscsssesssssssesesesesesssesssesesesssessesssesssesseesssesssssssesssessseeseoesees 17 1 INTERFACE COMPONENT 2 2 17 1 INTERFACE LINKING DISCRETE NODE OPTION eee eee 17 2 INTERFACE LINKING 5 17 3 INTEREACELINKING EDGEB e e Ree ete cox 17 4 SINTTEREACE JOY neuen eerte eo a ep 17 5 INTERPACE SPRINGBAGCK nre bI REB ebd
11. 3 12 BOUNDARY RADIATION OPTION essene cridor teess ierit rere Fete ee erp eite 3 14 BOUNDARY SEIDING PLEANE tet eete teer teer seats eor ent tee Peters tet prepa 3 16 BOUNDARY SPC OPTION nne rit RR 3 17 BOUNDARY SYMMETRY 3 18 BOUNDARY TEMPERATURE OPTION 3 19 BOUNDARY USA SURFACE tette eter te Rees 3 20 M o 4 1 CONSTRAINED EXTRA NODES 4 2 CONSTRAINED GENERALIZED WELD OPTION eene eene 4 3 CONSTRAINED JOINT OPTION tv ipta v Pieter done 4 10 CONSTRAINED JOINT STIFFNESS 4 13 CONSTRAINED LEINEAR nde dois ee vate 4 22 CONSTRAINED NODAL RIGID BODY OPTION eee 4 25 CONSTRAINED NODB SET rer btt e tonne FREUE ERE EIER 4 29 CONSTRAINED RIGID 8 4 31 CONSTRAINED RIGID BODY 5 85 4 32 CONSTRAINED RVE 4 35 CONSTRAINED SHELL 4 36 CONSTRAINED SHELL TO 5 4 37 CONSTRAINED SPOTWELD neret eger rere re ere rre E ere 4 39 CONSTRAINED TIE BREANK eb hr ep WE 4 41 CONSTRAINED TIED NODES FAILURE
12. a a am PRTLST 32 OUTPUT TIMES FOR ASCII FILES ABOVE WHEN SOLUTION TIME EXCEEDS THE OUTPUT TIME A PRINT STATE IS DUMPED QQQ0Q0000000000000000000300n0 COMMON RBKENG ENRBDY RBDYX RBDYY RBDYZ TOTAL RIGID BODY ENERGIES AND MOMENTUMS ENRBDY RIGID BODY KINETIC ENERGY RBDYX RIGID BODY X MOMENTUM RBDYY RIGID BODY Y MOMENTUM RBDYZ RIGID BODY Z MOMENTUM COMMON RBKENG ENRBDY RBDYX RBDYY RBDYZ TOTAL RIGID BODY ENERGIES AND MOMENTUMS SWXMOM STONEWALL SWYMOM STONEWALL SWZMOM STONEWALL 2 ENRBDY STONEWALL KINETIC ENERGY COMMON DEENGS DEENG DEENG TOTAL DISCRETE ELEMENT ENERGY C 2 LS DYNA3D Version 936 10 20 Appendix C COMMON ENERGY XPE XPE TOTAL INTERNAL ENERGY IN THE FINITE ELEMENTS DIMENSION VT 3 VR 3 AT 3 AR 3 UT 3 UR 3 XMST XMSR RBDYN USRHV SAMPLE MOMENTUM AND KINETIC ENERGY CALCULATIONS REMOVE ALL COMMENTS IN COLUMN 1 BELOW TO ACTIVATE INITIALIZE KINETIC ENERGY XKE AND X Y Z MOMENTUMS XKE 2 SWKENG 2 ENRBDY XM SWXMOM RBDYX YM SWYMOM RBDYY ZM SWZMOM RBDYZ NUMNP 2 NUMNP IF NDOF EQ 6 THEN NUMNP 2 NUMNP NUMNP ENDIF PRINT NDOF IF IRBODY EQ 0 THE
13. Card Format Card 1 3 4 5 6 7 8 SECID ELFORM HRF al ae Card 2 EH Scie Discrete 1 1 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 EQ 4 Belytschko Schwer full cross section integration EQ 5 Belytschko Schwer tubular beam with cross section integration EQ 6 discrete beam cable 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 23 2 SECTION LS DYNA3D Version 936 SECTION VARIABLE DESCRIPTION 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 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 TSI Beam thickness CST 0 0 2 0 or outer diameter CST 1 0 in s direc
14. END 14 2 INCLUDE LS DYNA3D Version 936 INITIAL INITIAL The keyword INITIAL provides a way of initializing velocities and detonation points The keyword control cards in this section are defined in alphabetical order INITIAL_DETONATION INITIAL MOMENTUM INITIAL STRESS BEAM INITIAL STRESS SHELL NITIAL STRESS SOLID INITIAL TEMPERATURE OPTION 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 LS DYNA3D Version 936 15 1 INITIAL INITIAL INITIAL DETONATION Purpose Define points to initiate the location of high explosive detonations Card Format Card 1 1 2 3 4 5 6 7 8 Variable Optional card required if and only if PID 1 Card 2 1 2 3 4 5 6 7 8 Remark VARIABLE DESCRIPTION PID Part ID of high explosive material to be lit see PART However two other options are available 1 an acoustic boundary also BOUNDARY_USA_SURFACE EQ 0 all high explosive materials are considered X x coordinate of detonation point see Figure 15 1 Y y coordinate of detonation point Z z coordinate of detonation point LT Lighting time for detonation point This time is ignored for an acoustic boundary 15 2 IN
15. XJVH YJVH ZJVH unless both NODE1 and NODE2 are defined In which case the coordinates of the nodes give by NODE1 NODE2 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 1 14 AIRBAG LS DYNA3D Version 936 AIRBAG 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 Virtual origin Cone center line Pressure is applied to sufaces that are in the line of sight to the virtual origin Gaussian profile Virtual origin Figure 1 1 Jetting configuration for a driver s side airbag and b the pa
16. _ OPTION S Do auo oae 19 234 MAT_ THERMAL Se NU S ORA ed 19 235 THERMAL 11441 19 236 THERMAL ISOTROPIC TD adatti en eo er RO ce ot 19 238 THERMAL TD eterne tnnt 19 240 THERMAL ISOTROPIC PHASE CHANGE een 19 243 THERMAL 5 TD LC 19 246 NODE fr ntn 20 1 MEER 20 1 ed Resende 21 1 PART OPTION oe ane tal toe atten tara atta arenes 21 1 RICD WA 22 1 RIGIDWALL GEOMETRIC OPTION OPTION ettet 22 2 RIGIDWALL_PLANAR_ OPTION _ OPTION _ OPTION et 22 8 SECTION Oi SCR INE NUN RON INS au neh tien 23 1 SUECTIONSHEBANIS 5 set 23 2 FSECTION DISCRETE Lus todo dto eda cen Ranh Cokie Me Manet 23 6 5 23 8 SHED 23 9 SBECTIONUSOLID2OPEION 23 12 viii LS DYNA3D Version 936 TABLE OF CONTENTS SECTION TSHELD HP eee ene 23 14 24 1 H BEAM S SES ENG 24 2 SET DIS C
17. n C u uy ka 1 Its velocities and accelerations are given by n C uy gt c 2 71 Cee 2 k 2 1 respectively In the implementation a transformation matrix L is constructed relating the unconstrained and constrained degrees of freedom The constrained accelerations used in iod SC the above equation are given by s x wil ue LS DYNA3D Version 936 4 23 CONSTRAINED CONSTRAINED 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 Remark 1 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 4 24 CONSTRAINED LS DYNA3D Version 936 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 I
18. v3 27 3731 37373 37373 33 3 P respectively Card 2 7 8 LS DYNA3D Version 936 15 9 INITIAL INITIAL VARIABLE EID NINT SIGIJ EPS 15 10 INITIAL DESCRIPTION Element ID Number of integration points either 1 or 8 Define the IJ stress component Effective plastic strain LS DYNA3D Version 936 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 only analysis see LOAD THERMAL option Card Format Card 1 1 2 3 4 5 6 7 8 Type VARIABLE DESCRIPTION NSID NID Nodal set ID or nodal point ID see also SET NODES EQ 0 all nodes are included set option only TEMP Temperature at node or node set Remark 1 If a nodal temperature is specified on more than one input card then the last set input will determine its temperature unless it is specified on a INITIAL_TEMPERATURE_NODE card LS DYNA3D Version 936 15 11 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 Ca
19. 4 tm 19 182 MAT CABEEB DISCRETE EAM ioco eet teen tu tede decet e ena 19 185 MAT BILKHU DUBOIS TOAM ee eoe e ied 19 187 MAT GENERAL VISCOELASTIC R E TE nene eeen E 19 189 MAT HYPEREEASTIC RUBBER 2 eret eio teet Tot ie Posi rete 19 193 MAT OGDEN RUBBER rte ertet tepore yep ee pep tee ete eg erp egre e grt pod 19 197 LS DYNA3D Version 936 Vii TABLE OF CONTENTS MAT SOIL CONCRETE stet et Ea al 19 200 HYSTERETIC SOIL eerte tentent ttt titt 19 204 PLASTICITY WITH DAMAGE ettet 19 207 VISCOELASTIC ttt 19 210 MAT_CELLULAR_RUBBER a tento ears 19 213 IMAT ACOUSTIC E tat tuu dius 19 218 IMATSSPRING ELASTIC euer toto tart ea Nd Lap E haat ate cma tna 19 221 SMATSODAMPER ora testata om te dU ROREM RR 19 222 SPRING ELASTOPLASTIC eerte tentent tette tie 19 223 SPRING NONLINEAR 8 002 41 22 2 20000100000 19 224 DAMPER NONLINEAR VISCOUS ettet 19 225 SPRING GENERAL NONLINEAR eerte ttti 19 226 AMATO SPRING NEAGOMBER cect 19 229 SMAT SPRINGCINBDASTIG d ettontdsen dultentda etna e dtd an buta 19 231 ee Em m 19 232
20. Appendix G ZMI Set position of zmin plane ZMIN value in normalized model dimesions gt ZOUT Zoom out using mouse to set displays size expansion and position G 6 LS DYNA3D Version 936 Appendix H APPENDIX H Interactive Material Model Driver INTRODUCTION The interactive material model driver in LS DYNA3D allows calculation of the material constitutive response to a specified strain path Since the constitutive model subroutines in LS DYNA3D are directly called by this driver the behavior of the constitutive model is precisely that which can be expected in actual applications In the current implementation the constitutive subroutines for both shell elements and solid elements can be examined INPUT DEFINITION The material model driver is invoked by setting the total number of beam shell and solid elements to zero in a standard LS DYNA3D input file The number of material model definitions should be set to one the number of load curves should be nine and the termination time to the desired length of the driver run The complete state dump interval is interpreted as the time step to be used in the material model driver run Plotting information is saved for every step of a driver run and sufficient memory is allocated to save this information in core for the interactive plotting phase The input deck consists only of the TITLE card the CONTROL cards one MATERIAL DEFINITION and NINE LOAD CURVES describing the strain path
21. Card 2 3 4 OPTION LIST The next card terminates the input 1 2 3 4 5 6 7 8 PIDI PID2 PID3 PID4 PID5 PID6 PID7 PID8 24 6 SET LS DYNA3D Version 936 SET Card 2 3 4 OPTION COLUMN The next card terminates the input 1 2 3 4 5 6 7 8 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 A4 Fourth part attribute Remarks 1 Part attributes 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_ LS DYNA3D Version 936 24 7 SET SET BODY STOPPERS one attribute can be defined DA1 the closure distance which activates the stopper constraint 2 The default part attributes can be overridden on the part cards otherwise Al DA1 etc 24 8 SET LS DYNA3D Version 936 SET SET SEGMENT Purpose Define a set of quadrilateral and triangular segments with optional identical or unique attributes Card Format Se ee ENEE I e VARIAB
22. Each belt material defines stretch characteristics and mass properties for a set of belt elements The user enters a load curve for loading the points of which are Strain Force Strain is defined as engineering strain i e 4 current length Strain Mice inii ii d initial length Another similar curve is entered to describe the unloading behavior Both loadcurves should start at the origin 0 0 and contain positive force and strain values only The belt material is tension only with zero forces being generated whenever the strain becomes negative The first non zero point on the loading curve defines the initial yield point of the material On unloading the unloading curve is shifted along the strain axis until it crosses the loading curve at the yield point from which 19 228 MAT LS DYNA3D Version 936 MAT unloading commences If the initial yield has not yet been exceeded or if the origin of the shifted unloading curve is at negative strain the original loading curves will be used for both loading and unloading If the strain is less than the strain at the origin of the unloading curve the belt is slack and no force is generated Otherwise forces will then be determined by the unloading curve for unloading and reloading until the strain again exceeds yield after which the loading curves will again be used A small amount of damping is automatically included This reduces high frequency oscillation but with realist
23. For the BINARY option the following cards apply Card Format Card 1 1 2 3 4 5 6 7 8 2 1 2 3 4 5 LS DYNA3D Version 936 8 13 DATABASE DATABASE VARIABLE NEIPH NEIPS MAXINT STRFLG SIGFLG SIGFLG EPSFLG RLTFLG ENGFLG 8 14 DATABASE DESCRIPTION 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 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 Number of shell integration points written to the LS TAURUS 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
24. LS DYNA3D gt outputfilename cr rzd3dump cr add usainputfilename cr We note that no prompts are provide for the second and third lines of input 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 LS DYNA3D Version 936 3 21 BOUNDARY 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 EXTRA NODES OPTION CONSTRAINED GENERALIZED WELD OPTION CONSTRAINED JOINT OPTION CONSTRAINED JOINT STIFFNESS OPTION CONSTRAINED LINEAR CONSTRAINED NODAL RIGID BODY OPTION CONSTRAINED NODE SET CONSTRAINED RIGID BODIES CONSTRAINED RIGID BODY STOPPERS CONSTRAINED RIVET CONSTRAINED SHELL TO SOLID CONSTRAINED SHELL IN SOLID CONSTRAINED SPOTWELD CONSTRAINED TIE BREAK CONSTRAINED TIED NODES FAILURE LS DYNA3D Version 936 4 1 CONSTRAINED 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
25. PSID Part set ID for springback see SET PART Define a list of nodal points that are constrained for the springback This section is terminated by an x indicating the next input section Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Node ID LS DYNA3D Version 936 29 27 RESTART RESTART VARIABLE TC RC 29 28 RESTART DESCRIPTION Tranlational constraint EQ 0 EQ 1 2 EQ 3 EQ 4 EQ 5 EQ 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 Rotational constraint EQ 0 EQ 1 EQ 2 EQ 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 LS DYNA3D Version 936 RESTART RIGID DEFORMABLE OPTION The OPTIONS available are CONTROL D2D 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 if part switching was activated in the time zero analysis See CONTROL DEFORMABLE RIGID for details of part switching LS
26. SUBROUTINE UCTRL2 NSI NTY TIME YCLE MSR NMN NSV NSN 1 THMR THSV VT XI UT ISKIP IDRINT NUMNP DT2 NINPUT UA Qe ke ee he e he e e e Se e e he e e k e k k k k he k e k e k k he k e k e k k k k k k k he k e ke k e k k k k k k k k k k C LIVERMORE SOFTWARE TECHNOLOGY CORPORATION LSTC Q COPYRIGHT 1987 1988 1989 JOHN HALLQUIST LSTC ALL RIGHTS RESERVED QU K k ke e e he e e e e e k he k e k se k k he k e k Se k k he k e k k k k ke k INTEGER CYCLE LS DYNA3D Version 936 USER SUBROUTINE FOR INTERFACE CONTROL NOTE LS DYNA3D USED INTERNAL NUMBERING SYSTEM TO ACCOMODATE ARBITRARY NODE NUMBERING ACCESS INFORMATION FOR USER NODE ADDRESS ARRAY LOCATION M LQF N 1 OBTAIN USER NODE NUMBER CORRESPONDING TO ARRAY ADDRESS M SET N LQFINV M 1 ARGUMENTS NSI NUMBER OF SLIDING INTERFACE INTERFACE TYPE EQ 4 SINGLE SURFACE NE 4 SURFACE TO SURFACE CURRENT SOLUTION TIME CYCLE CYCLE NUMBER MSR LIST MASTER NODES NUMBERS INTERNAL NUMBERING SCHEME NMN NUMBER OF MASTER NODES NSV NSN LIST OF SLAVE NODES NUMBERS IN INTERNAL NUMBERING SCHEME NSN NUMBER OF SLAVE NODES THMR MASTER NODE THICKNESS THSV NSN SLAVE NODE THICKNESS V
27. VARIABLE DESCRIPTION UNLENG Unit conversion factor for length MADYMO3D GM CAL3D lengths are multiplied by UNLENG to obtain LS DYNA3D lengths UNTIME Unit conversion factor for time UNTIME MADYMO3D GM CAL3D time is multiplied by UTIME to obtain LS DYNA3D time UNFORC Unit conversion factor for force UNFORC MADYMO3D GM CAL3D force is multiplied by UNFORC to obtain LS DYNA3D 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 MADYMOSGD relative to the LS DYNA3D model EQ 0 off EQ 1 on FLIPY Flag for flipping Y coordinate of CAL3D MADYMOGD relative to the LS DYNA3D model EQ 0 off EQ 1 on FLIPZ Flag for flipping Z coordinate of CAL3D MADYMOGD relative to the LS DYNA3D model EQ 0 off EQ 1 on LS DYNA3D Version 936 6 11 CONTROL CONTROL VARIABLE DESCRIPTION SUBCYL CAL3D MADYMO3D subcycling interval of cycles EQ 0 Set to 1 EQ n number of LS DYNA3D time steps between each CAL3D MADYMOOD step Then the position of the contacting rigid bodies is assumed to be constant for n LS DYNA3D time steps This may result in some increase in the spikes in contact thus this option should be used carefully As the CAL3D MADYMO GD programs usually work with a very small number of degrees of freedom not much gain in efficiency can be achieved 6 12 CONTROL LS DYNA3D Version 936 C
28. shown This behavior under uniaxial loading is assumed not to significantly couple in the transverse directions In tension the material behaves in a linear fashion until tearing occurs Although our implementation may be somewhat unusual it was motivated by Storakers 1986 The model uses tabulated input data for the loading curve where the nominal stresses are de fined as a function of the elongations i which are defined in terms of the principal stretches Aj as 19 144 MAT amp i 2 i 1 LS DYNA3D Version 936 MAT The stretch ratios are found by solving for the eigenvalues of the left stretch tensor Vij which is obtained via a polar decomposition of the deformation gradient matrix Fi Recall that RikUkj VikRij The update of Vi follows the numerically stable approach of Taylor and Flanagan 1989 After solving for the principal stretches we compute the elongations and if the elongations are compressive the corresponding values of the nominal stresses tj are interpolated If the elongations are tensile the nominal stresses are given by t Eg and the Cauchy stresses in the principal system become The stresses can now be transformed back into the global system for the nodal force calculations Remarks 1 When hysteretic unloading is used the reloading will follow the unloading curve if the decay constant D is set to zero If D is nonzero the decay to the original loading curve is gov
29. where T is the input material parameter which specifies the maximum hydrostatic tension sustainable by the material The elastic domain in 4 J5p space is then bounded by the failure envelope surface above the tension cutoff surface on the left and the cap surface on the right An additive decomposition of the strain into elastic and plastic parts is assumed 19 74 LS DYNA3D Version 936 MAT where is the elastic strain and is the plastic strain Stress is found from the elastic strain using Hooke s law o C e P where is the stress and is the elastic constitutive tensor The yield condition may be written and the plastic consistency condition requires that fy 9 k 1 2 3 ir where is the plastic consistency parameter for surface If fk lt 0 then 0 and the response is elastic If fk gt then surface is active and is found from the requirement that f j 70 Associated plastic flow is assumed so using Koiter s flow rule the plastic strain rate is given as the sum of contribution from all of the active surfaces P 3 ofk ya dk i L o One of the major advantages of the cap model over other classical pressure dependent plasticity models is the ability to control the amount of dilatency produced under shear loading Dilatency is produced under shear loading as a result of the yield surface having a positive slope in space so
30. 7 is the relaxation functions for the different stress measures This stress is addedto the stress tensor determined from the strain energy functional If we wish to include only simple rate effects the relaxation function is represented by six terms from the Prony series N g t E Gpe P m 1 We characterize this in the input by shear modulii G and decay constants D An arbitrary number of terms up to 6 may be used when applying the viscoelastic model For volumetric relaxation the relaxation function is also represented by the Prony series in terms of bulk moduli Y Prnt Kme 1 19 188 LS DYNA3D Version 936 MAT Figure 19 20 Relaxation curve This curve defines stress versus time where time is defined on a logarithmic scale For best results the points defined in the load curve should be equally spaced on the logarithmic scale Furthermore the load curve should be smooth and defined in the positive quadrant If nonphysical values are determined by least squares fit LS DYNA3D will terminate with an error message after the initialization phase is completed If the ramp time for loading is included then the relaxation which occurs during the loading phase is taken into account This effect may or may not be important LS DYNA3D Version 936 19 189 MAT MAT MAT HYPERELASTIC RUBBER This is Material Type 77 This material model provides a general hyperelastic rubber model combined
31. Appendix I APPENDIX I VDA Database VDA surfaces describe the surface of geometric entities and are useful for the simulation of sheet forming problems The German automobile and automotive supplier industry VDA has defined the VDA guidelines VDA 1987 for a proper surface definition used for the exchange of surface data information In LS DYNA3D this format can be read and used directly Some files have to be provided for proper linkage to the motion of the correlation parts materials in LS DYNA3D Linking is performed via names To these names surfaces are attached which in turn can be linked together from many files externally to LS DYNA3D Thus arbitrary surfaces be provided by a preprocessor and then can be written to various files The so called VDA file given on the LS DYNA3D execution line via V vda contains references to all other files It also contains several other parameters affecting the treatment in the contact subroutines see below The procedure is as follows If VDA surfaces are to be used the file specified by vda must have the following form The file is free formatted with blanks as delimiters Note that the characters and must be separated from the other input by spaces or new lines The vda file may contain any number of input file specifications of the form file afile bfile alias definitions alias definitions followed by optional runtime parameters and a final end statement The
32. BSTART TRAMP LCIDK NTK BSTARTK TRAMPK GI BETAI KI BETAKI MAT DESCRIPTION Material identification A unique number has to be chosen Mass density Elastic bulk modulus Load curve ID for deviatoric behavior if constants G and are determined via a least squares fit This relaxation curve is shown below Number of terms in shear fit If zero the default is 6 Currently the maximum number is set to 6 In the fit is set to zero 82 is set to BSTART 33 is 10 times f By is 100 times greater than 3 and so on If zero BSTART 01 Optional ramp time for loading Load curve ID for bulk behavior if constants Kj and Bx are determined via a least squares fit This relaxation curve is shown below Number of terms desired in bulk fit If zero the default is 6 Currently the maximum number is set to 6 In the fit Bx is set to zero Bk is set to BSTARTK is 10 times Bk is 100 times greater than and so on If zero BSTARTK 01 Optional ramp time for bulk loading Optional shear relaxation modulus for the ith term Optional shear decay constant for the ith term Optional bulk relaxation modulus for the ith term Optional bulk decay constant for the ith term Rate effects are taken into accounted through linear viscoelasticity by a convolution integral of the form LS DYNA3D Version 936 t oj I ei t t M dt 19 187 MAT MAT where gjjxj t
33. Card Format Card 1 1 2 3 4 5 6 7 8 Variable Default Card 2 Default 19 54 MAT LS DYNA3D Version 936 MAT Optional Card Format for output Must be included but may be left blank Card 3 selel VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus Reasonable values have to be chosen for contact analysis choice of penalty see remark below PR Poisson s ratio Reasonable values have to be chosen for contact analysis choice of penalty see remark below N not CAL3D coupling flag n EQ 0 use normal LS DYNA3D rigid body updates GT 0 the rigid body is coupled to MADYMO ellipsoid number LT 0 the rigid body is coupled to MADYMO plane number Inl COUPLE Coupling option if applicable EQ 1 attach VDA surface in ALIAS defined in the eighth field and automatically generate a mesh for viewing the surface in LS TAURUS MADYMO3D CAL3D coupling option EQ 0 the undeformed geometry input to LS DYNA3D corresponds to the local system for MADYMO CAL3D The finite element mesh is input EQ 1 the undeformed geometry input to LS DYNA3D corresponds to the global system for MADYMO CAL3D EQ 2 generate a mesh for the ellipsoids and planes internally in LS DYNA3D M MADYMO CAL3D Coupling option flag EQ 0 use normal LS DYNA3D rigid body updates EQ m this rigid body corresponds to MADYMO CAL3D rigid body
34. EQ 11 Fast co rotational Hughes Liu SHRF Shear factor A suggested value is 5 6 NIP Number of through shell thickness integration points EQ 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 QR IRID Quadrature rule or Integration rule ID see INTEGRATION SHELL LT 0 0 absolute value is specified rule number EQ 0 0 Gauss up to five points are permitted EQ 1 0 trapezoidal not recommend for accuracy reasons ICOMP Flag for layered composite material model EQ 1 material angle is defined for each through thickness integration point Thus each layer has one integration point Shell thickness at node nj see Figure 10 14 thickness is defined on the ELEMENT SHELL OPTION card T2 Shell thickness at node n5 see comment for T1 above T3 Shell thickness at node see comment for T1 above T4 Shell thickness at node n4 see comment for T1 above NLOC Location of reference surface Hughes Liu shell only EQ 1 0 top surface EQ 0 0 mid surface default EQ 1 0 bottom surface Bl material angle at first integration point B2 B material angle at second integration point 23 10 SECTION LS DYNA3D Version 936 VARIABLE B3 B8 Bnip LS DYNA3D Version 936 SECTION DESCRIPTION material angle at third integr
35. HOURGLASS Purpose Define hourglass and bulk viscosity properties Using the PART definition this specification is connected to the elements Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION HGID Hourglass ID Unique numbers have to be specified THQ Hourglass control type For solid elements five options are available For quadrilateral shell and membrane lements the hourglass control is based on the formulation of Belytschko and Tsay i e options 1 3 are identical and options 4 5 are identical EQ 0 default 1 EQ 1 standard LS DYNA3D 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 A discussion of the hourglass control for shell elements follows at the end of this section LS DYNA3D Version 936 13 1 HOURGLASS HOURGLASS VARIABLE DESCRIPTION QM Hourglass coefficient Values of QM that exceed 15 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 QM is taken as the membrane hourglass coefficient the bending as QB and warping as QW These coefficients can be specified independently but generally
36. LS DYNA3D Version 936 26 1 TITLE 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 DYNA3D 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 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION FILE Filename of file created by ANSYS see remarks below The supported options include Version ANSYS Keyword LS DYNA3D Keyword All N Type NODE Val1 Val2 Val3 NODE All EN Type 11 12 13 14 15 16 17 18 ELEMENT All MPDATA R5 0 LENGTH Lab MAT STLOC VALI VAL2 VAL3 MAT ELASTIC LS DYNA3D Version 936 27 1 TRANSLATE TRANSLATE Version ANSYS Keyword LS DYNA3D Keyword All ET Type PART amp SECTION All R R5 0 NSET Type STLOC VALI V AL2 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 INITIAL VELOCITY NODE 5 NODF eq Ui ROT 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 3 LKEY eq lcid Lab eq pressure LOAD SEGMENT Remarks 1 Supported keywords as described in the SASI ANSYS Manual chapter on Exporting a Finite Element Model 2 Solid elements and shell elements cannot have the same
37. SIGY Yield stress ETAN Tangent modulus ignored if LCSS GT 0 is defined EPPF Plastic strain at which material softening begins logrithmic TDEL Minimum time step size for automatic element deletion C Strain rate parameter C see formula below P Strain rate parameter P see formula below LCSS Load curve ID Load curve ID defining effective stress versus effective plastic strain If defined EPS1 EPS8 and 51 58 are ignored LCSR Load curve ID defining strain rate scaling effect on yield stress EPPFR Plastic strain at which material ruptures logrithmic EPS1 EPS8 Effective plastic strain values optional if SIGY is defined At least 2 points should be defined ES 1 ES8 Corresponding yield stress values to EPS1 EPS8 LS DYNA3D Version 936 19 205 MAT MAT The stress strain behavior may be treated by a bilinear stress strain curve by defining the tangent modulus ETAN Alternately a curve similar to that shown in Figure 19 4 is expected to be defined by EPS1 ES1 EPS8 ES8 however an effective stress versus effective plastic strain curve LCSS may be input instead if eight points are insufficient The cost is roughly the same for either approach The most general approach is to use the table definition LCSS discussed below Two options to account for strain rate effects are possible I Strain rate may be accounted for using the Cowper and Symonds model which scales the yield stress with the factor
38. are the relaxation functions for the different stress measures This stress is addedto the stress tensor determined from the strain energy functional Since we wish to include only simple rate effects the relaxation function is represented by one term from the Prony series N g t 90 1 given by g t Eje Pi This model is effectively a Maxwell fluid which consists of a damper and spring in series We characterize this in the input by a shear modulus G and decay constant The Mooney Rivlin rubber model model 27 is obtained by specifying n 1 without air pressure and viscosity In spite of the differences in formulations with Model 27 we find that the results obtained with this model are nearly identical with those of material type 27 as long as large values of Poisson s ratio are used LS DYNA3D Version 936 19 213 MAT MAT Rubber Block With Entrapped Air Figure 19 24 Cellular rubber with entrapped air By setting the initial air pressure to zero an open cell cellular rubber can be simulated 19 214 MAT LS DYNA3D Version 936 MAT MAT ACOUSTIC This is Material Type 90 This model is appropiate for tracking low pressure stress waves in an acoustic media such as air or water and can be used only with the acoustic pressure element formulation The acoustic pressure element requires only one unknown per node This element is very cost effective Optionally cavitation can be allowed C
39. 19 24 MAT LS DYNA3D Version 936 MAT MAT HIGH EXPLOSIVE BURN This is Material Type 8 It allows the modeling of the detonation of a high explosive In addition an equation of state must be defined See Wilkins 1969 and Giroux 1972 Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density D Detonation velocity PCJ Chapman Jouget pressure BETA Beta burn flag BETA see comments below EQ 0 0 beta programmed burn EQ 1 0 beta burn only EQ 2 0 programmed burn only K Bulk modulus BETA 2 0 only G Shear modulus BETA 2 0 only SIGY Oy yield stress BETA 2 0 only If programmed burn is used the explosive model will behave as an elastic perfectly plastic material if the bulk modulus shear modulus and yield stress are defined Otherwise any compression of the explosive material will cause detonation Burn fractions which multiply the equations of states for high explosives control the release of chemical energy for simulating detonations the initialization phase a lighting time is computed for each element by dividing the distance from the detonation point to the center of the element by the detonation velocity D If multiple detonation points are defined the closest point determines tj The burn fraction F is taken as the maximum LS DYNA3D Version 936 19 25 MAT MAT max F1 F2 where ES EET
40. 2 oH 2 2 1l c c y y3 2 11 2202 y y3 where it has been assumed that oy Oy Letting K the yield criteria can be written y3 F o Oe Oy 19 114 MAT LS DYNA3D Version 936 MAT where 2222 2 2 2 2 F s o 033 K 633 511 022 2 K 1 2 2 _2 2 2103 03 eot ex2 Jen The rate of plastic strain is assumed to be normal to the yield surface so is found from _ OF e y Now consider the case of plane stress where 633 0 Also define the anisotropy input parameter R as the ratio of the in plane plastic strain rate to the out of plane plastic strain rate It then follows that Using the plane stress assumption and the definition of R the yield function may now be written 1 2 2 2 2R 2R 1 F o 059 04 4 055 2 _90 s efi 22 R41 11922 R 1 12 LS DYNA3D Version 936 19 115 MAT MAT MAT BLATZ KO FOAM This is Material Type 38 This model is for the definition of rubber like foams of polyurethane It is a simpe one parameter model with a fixed Poisson s ratio of 25 Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus The strain energy functional for the compressible foam model is given by w SE eaim s 2 M Blatz and Ko 1962 suggested this form for a 47 percent v
41. 2 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 3 Do not define for discrete beams beam type 6 see SECTION BEAM Define for resultant beam elements only see SECTION LS DYNA3D Version 936 11 3 ELEMENT ELEMENT The third node i e the reference node must be unique to each beam element if the coordinate update option is used see CONTROL OUTPUT Figure 11 1 LS DYNA3D beam elements Node n3 determines the initial orientation of the cross section 11 4 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT DISCRETE Purpose Define a discrete spring or damper element between two nodes or a node and ground Card Format 518 E16 0 18 E16 0 OFFSET Variable ic di UT UT iid a VARIABLE DESCRIPTION EID Element ID A unique number has to be used PID Part ID see PART N1 Nodal point 1 N2 Nodal point 2 If zero the spring damper connects node N1 to ground VID Orientation option EQ 0 the spring damper acts along the axis from node N1 to N2 NE 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 Th
42. 2 2 2 2 2 5 2 7 4 4 After failure the discrete element is deleted If failure is included either one or both of the criteria may be used LS DYNA3D Version 936 19 173 MAT MAT MAT SID DAMPER DISCRETE BEAM This is Material Type 69 The side impact dummy uses a damper that is not adequately treated by the nonlinear force versus relative velocity curves since the force characteristics are dependent on the displacement of the piston See also notes below Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type Card 2 Variable LCIDF LCIDD Type Read in up to 16 orifice locations with orifice location per card Input is terminated when a card is found Cards 3 Variable ORFLOC ORFRAD Type 19 174 MAT LS DYNA3D Version 936 VARIABLE MID RO ST C3 STF RHOF C2 LCIDF LCIDD SO ORFLOC ORFLOC MAT DESCRIPTION Material identification A unique number has to be chosen Mass density see also volume on SECTION BEAM definition S piston stroke S must equal or exceed the length of the beam element see Figure 19 16 below d piston diameter R default orifice radius h orifice controller position K damping constant LT 0 0 IKI is the load curve number ID see DEFINE CURVE defining the damping coefficient as a function of the absolute value of the relative velocity C discharge
43. 5 XT YT YC 19 140 MAT DESCRIPTION Material axes option see Figure 19 1 EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector Define coordinates of point p for AOPT 1 Define components of vector a for AOPT 2 Define components of vector v for AOPT 3 Define components of vector d for AOPT 2 Time step size criteria for element deletion EQ lt 0 no element deletion by time step size EQ 0 lt tfai lt 1 element is deleted when its time step is smaller than the given value EQ gt 1 element is deleted when the quotient of the actual time step and the original time step drops below the given value Longitudinal compressive strength Softening reduction factor for ma
44. 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 29 24 RESTART LS DYNA3D Version 936 RESTART DELETE OPTION Available options are CONTACT ENTITY PART ELEMENT BEAM ELEMENT SHELL ELEMENT SOLID ELEMENT TSHELL Purpose Delete contact surfaces parts or elements by a list of IDs For CONTACT ENTITY or PART option Card Format Type 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 LS DYNA3D Version 936 29 25 RESTART RESTART For the four ELEMENT options Termination of input is when the next card is read Card Format Type VARIABLE DESCRIPTION ESID Element set ID see SET SOLID SET BEAM SET SHELL SET TSHELL 29 26 RESTART LS DYNA3D Version 936 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 input deck for LS NIKE3D and a stress initialization file for LS NIKE3D are written Card Format Type VARIABLE DESCRIPTION
45. Care should be taken when defining the curves so that extrapolated values do not lead to negative yield stresses At the beginning of the stress update each element s stresses and strain rates are transformed into the local element coordinate system For the uncompacted material the trial stress components are updated using the elastic interpolated moduli according to n ria n aa Eqgh bag n4 1 irit n Opp Opp EppA py n4 1 ria E cc Oce ESAE on Sab 264 nq ria n bc Ope 2Gp AE be _ Oca 2G Each component of updated stresses is then independently checked to ensure that they do not exceed the permissible values determined from the load curves e g if M js V then n4 1 irit ij n l ria ij oj oj V On Card 2 is defined by LCA for the aa stress component LCB for the bb component LCC for the cc component and LCS for the ab bc cb shear stress components The parameter A is either unity or a value taken from the load curve number LCSR that defines X as a function of strain rate Strain rate is defined here as the Euclidean norm of the deviatoric strain rate tensor 19 82 MAT LS DYNA3D Version 936 MAT For fully compacted material it is assumed that the material behavior is elastic perfectly plastic and the stress components updated according to dev n 1 2 5071
46. Each boundary node in this boundary plane is constrained to its corresponding node in the first node set Node sets NSIDI 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 differ all by the same angle Only globally defined axes of rotation are possible 3 4 BOUNDARY LS DYNA3D Version 936 BOUNDARY Conformable Interface ide Segment Figure 3 1 With cyclic symmetry only one segment is modeled LS DYNA3D Version 936 3 5 BOUNDARY 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 2 6 7 8 Variable Default For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 Variable Default 3 6 BOUNDARY LS DYNA3D Version 936 BOUNDARY Define the following card for both options Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 Default VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT NLNO2 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 vers
47. In Version 92X these elements were specified in separate and disjoint sections of the User s Manual Materials and contact algorithms are specified by names and not by type numbers making the data more readable by those less familiar with the program LS DYNA3D User s Manual is alphabetically organized in logical sections of input data Each logical section relates to a particular input There is a control section for resetting LS DYNA3D 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 pd n2 n3 n4 10301 pid nl n2 n3 n4 Alternatively acceptable input could also be of the form DEFINE ONE NODE NODE 10101 X y 7 DEFINE ONE SHELL ELEMENTS 1 8 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION ELEMENT SHELL 10201 pd nol n2 n3 n4 DEFINE ONE MORE NODE NODE 10201 X y 7 DEFINE ONE MORE SHELL ELEMENTS ELEMENT SHELL 10301 pd nol n2 n3 n4 A data block begins with a keyword followed by data pertaining
48. NX NY NZ PHASE Remarks DESCRIPTION x coordinate on rotational axis y coordinate on rotational axis Z coordinate on rotational axis x direction cosine y direction cosine Z direction cosine Flag specifying phase of the analysis the velocities apply to 0 Velocities applied immediately EQ 1 Velocities applied after dynamic relaxation 1 This generation input must not be used with INITIAL_VELOCITY or INITIAL_ VELOCITY_NODE options 2 The velocities are initialized in the order the INITIAL VELOCITY GENERATION input is defined Later input via the INITIAL VELOCITY GENERATION keyword may overwrite the velocities previously set 15 16 INITIAL LS DYNA3D Version 936 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 Variable Default Default Type LS DYNA3D Version 936 16 1 INTEGRATION INTEGRATION VARIABLE IRID NIP RA ICST TF TW SREF TREF 16 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 defined by the product of the specified thickness in the s direction and the thickness in the t direction See also ICST below and Figure 16 1 Standard cross
49. SIG 1 P G2 EPS 1 DAVG SIG 2 SIG 2 P G2 EPS 2 DAVG SIG 3 SIG 3 P G2 EPS 3 DAVG SIG 4 SIG 4 P EPS 4 SIG 5 51 5 P EPS 5 SIG 6 SIG 6 P EPS 6 ELSEIF ETYPE EQ SHELL THEN GC CAPA G Q1 CM 1 CM 2 1 0 CM 2 1 0 2 0 CM 2 Q3 1 Q1 G2 EPS 3 Q1 EPS 1 EPS 2 Q3 DAVG EPS 1 EPS 2 EPS 3 3 P DAVG CM 1 1 2 CM 2 SIG 1 SIG 1 P G2 EPS 1 DAVG A 2 LS DYNA3D Version 936 Appendix A SIG 2 SIG 2 P G2 EPS 2 DAVG SIG 3 20 0 SIG 4 SIG 4 4G EPS 4 SIG 5 SIG 5 GC EPS 5 SIG 6 SIG 6 GC EPS 6 ELSEIF ETYPE EQ BEAM THEN Q1 CM 1 CM 2 1 0 CM 2 1 0 2 0 CM 2 Q3 0142 0 G Gc CAPA G 1 03 03 01 01 C221 Q3 DETI C231 Q1 DETI FAC 221 23 01 5 2 5 1 FAC SIG 2 C22I SIG 3 23 EPS 3 EPS 1 FAC SIG 2 C23I SIG 3 C221 DAVG EPS 1 EPS 2 CEPS 3 3 P DAVG CM 1 1 2 CM 2 SIG 1 SIG 1 P G2 EPS 1 DAVG SIG 2 0 0 SIG 3 0 0 SIG 4 SIG 4 GC EPS 4 SIG 5 0 0 SIG 6 SIG 6 GC EPS 6 ENDIF RETURN END LS DYNA3D Version 936 Appendix B APPENDIX B User Defined Airbag Sensor The addition of a user sensor subroutine into LS DYNA3D is relatively simple The sensor is mounted on a rigid body which is attached to the structure The motion of the sensor is provided in t
50. T HC C2 C3 C4 C5 C6 C7 C8 C9 C10 Cll C12 C13 C14 C15 C16 C17 C18 DESCRIPTION Material identification A unique number has to be chosen Mass density Young s modulus psi Poisson s ratio Initial temperature 9R Heat generation coefficient C Rypsi Psi Psi l s l psi Psi l psi s psi l psi s LS DYNA3D Version 936 MAT 19 127 MAT MAT VARIABLE DESCRIPTION Al initial value of internal state variable 1 A2 initial value of internal state variable 2 A3 04 initial value of internal state variable 3 A4 05 initial value of internal state variable 4 5 initial value of internal state variable 5 A6 K initial value of internal state variable 6 sec psi OR sec MPa R sec MPA K 1 145 5 9 1 145 5 9 5 0 145 5 0 1 145 5 0 145 5 0 145 5 0 1 145 5 0 145 5 0 145 5 9 1 145 5 0 19 128 MAT LS DYNA3D Version 936 MAT The kinematics associated with the model are discussed in references Hill 1948 Bammann and Aifantis 1987 Bammann 1989 The description below is taken nearly verbatim from Bammann 1989 With the assumption of linear elasticity we can write o ur p ji 2p where the Cauchy stress is convected with the elastic spin W as o 0 W o oW This is equivalent to writing
51. Type 19 210 MAT LS DYNA3D Version 936 Card Format Card 3 Type VARIABLE MID RO PR Define if N gt 0 SGL SW ST LCID Define if N 0 C10 Col Cll C20 C02 LS DYNA3D Version 936 MAT DESCRIPTION Material identification A unique number has to be chosen Mass density Poisson s ratio typical values are between 0 to 2 Due to the large compressibility of air large values of Poisson s ratio generates physically meaningless results Order of fit currently lt 3 If 120 then a least square fit is computed with uniaxial data The parameters given on card 2 should be specified Also see RIVLIN RUBBER material model 27 A Poisson s ratio of 5 is assumed for the void free rubber during the fit The Poisson s ratio defined on Card 1 is for the cellular rubber A void fraction formulation is used Specimen gauge length lo Specimen width Specimen thickness Load curve ID giving the force versus actual change AL in the gauge length Coefficient C10 Coefficient Coefficient C11 Coefficient C29 Coefficient Co 19 211 MAT MAT VARIABLE DESCRIPTION PO Initial air pressure Po PHI Ratio of cellular rubber to rubber density IVS Initial volumetric strain yo G Optional shear relaxation modulus G for rate effects viscosity BETA Optional decay constant B4 Rubber is generally considered to be fully incompressible since the bulk mo
52. Using the information on rigid body locations LS DYNA3D proceeds to update the stresses and history variables of all of the deformable structures and computes the resultant forces acting on all rigid bodies 3 The resultant forces are stored into an OSP common block along with the current time step Control is then returned to the OSP so that the step can be completed by the OSP determining the new positions of the rigid bodies based on the applied forces At the end of the calculation LS DYNA3D terminates normally closing its files and then control is returned to OSP which will also terminate normally The termination time for the coupled run is taken as the minimum of the termination time provided to LS DYNA3D and the termination time provided to the OSP The executable for the coupling with MADYMO currently needs to be specially created at each site TNO provides all of the appropriate load modules with their libraries and the appropriate load modules for LS DYNA3D may be obtained by the corporate contact point at the LS DYNA3D distributor A complete executable must then be made by linking the two libraries A revised password file must be obtained from TNO prior to running the coupled code Coupling with CAL3D requires special on site modification of the client s CAL3D version to eliminate conflicting I O unit numbers and to ensure that the common block lengths between the codes are consistent LSTC does not distribute or support CAL3D
53. Variable LCIDTR LCIDTS LCIDTT LCIDRR LCIDRS LCIDRT Type Card 2 Variable LCIDTDR LCIDTDS LCIDTDT LCIDRDR LCIDRDS LCIDRDT Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density see also volume in SECTION BEAM definition LCIDTR Load curve ID defining translational force resultant along local r axis versus relative translational displacement see Figure 19 14 LCIDTS Load curve ID defining translational force resultant along local s axis versus relative translational displacement LCIDTT Load curve ID defining translational force resultant along local t axis versus relative translational displacement LCIDRR Load curve ID defining rotational moment resultant about local r axis versus relative rotational displacement LCIDRS Load curve ID defining rotational moment resultant about local s axis versus relative rotational displacement LS DYNA3D Version 936 19 167 MAT MAT VARIABLE DESCRIPTION LCIDRT Load curve ID defining rotational moment resultant about local t axis versus relative rotational displacement LCIDTDR Load curve ID defining translational damping force resultant along local r axis versus relative translational velocity LCIDTDS Load curve ID defining translational damping force resultant along local s axis versus relative translational velocity LCIDTDT Load curve ID defining translational damping force resultant along local t axis ver
54. Wright Patterson AFB 547 576 1965 Belytschko T B and A H Marchertas Nonlinear Finite Element Method for Plates and its Application to the Dynamic Response of Reactor Fuel Subassemblies Trans ASME J Pressure Vessel Tech 251 257 1974 Belytschko and C S Tsay Explicit Algorithms for Nonlinear Dynamics of Shells AMD Vol 48 ASME 209 231 1981 Belytschko T B and C S Tsay Explicit Algorithms for Nonlinear Dynamics of Shells Comp Meth Appl Mech Eng 43 251 276 1984 Belytschko T B and C S Tsay A Stabilization Procedure for the Quadrilateral Plate Element with One Point Quadrature Int J Num Method Eng 19 405 419 1983 Belytschko T B H Stolarski and Carpenter C Triangular Plate Element with One Point Quadrature Int J Num Meth Eng 20 787 802 1984 LS DYNA3D Version 936 30 1 REF REFERENCES Belytschko T B L Schwer and M J Klein Large Displacement Transient Analysis of Space Frames Int J Num Eng 11 65 84 1977 Benson D J and J O Hallquist A Simple Rigid Body Algorithm for Structural Dynamics Programs Int J Numer Meth Eng 22 1986 Benson D J and J O Hallquist A Single Surface Contact Algorithm for the Postbuckling Analysis of Shell Structures Comp Meths Appl Mech Eng 78 141 163 1990 Bilkhu S S M Founas and G S Nasholtz Material Modeling of Structural Foams in Finite
55. 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 12 24 EOS LS DYNA3D Version 936 EOS 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 RS R6 R3 T PeR e pes V FRER where Vy and Ty are 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 1 XP2 sT Poaha p Op Vp CCRIT As the reaction proceeds the unreacted and product pressures and temperatures are assumed to be equilibrated Tp T p Py and the relative volumes are additive V 1 F V F V 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 GROW 1 P FREQ M FMXIG AR 1 FMXIG ES GROW2 P FREQ EN FMXIG A R 1 FMXIG ES2 If F exceeds FMXGR the GROW term is set equal to zero and if F is less th
56. constrained x and y rotations constrained y and z rotations constrained z and x rotations constrained x y and z rotations 17 7 INTERFACE LOAD The keyword LOAD provides way of defining applied forces keyword control cards in this section are defined in alphabetical order LOAD BEAM OPTION LOAD BODY OPTION LOAD BODY GENERALIZED LOAD BRODE LOAD DENSITY DEPTH LOAD HEAT GENERATION OPTION LOAD NODE OPTION LOAD RIGID BODY LOAD SEGMENT LOAD SEGMENT SET LOAD SHELL OPTION LOAD SUPERPLASTIC FORMING LOAD THERMAL OPTION LOAD THERMAL CONSTANT LOAD THERMAL CONSTANT NODE LOAD THERMAL LOAD CURVE LOAD THERMAL TOPAZ LOAD THERMAL VARIABLE LOAD THERMAL VARIABLE NODE LS DYNA3D Version 936 18 1 LOAD LOAD LOAD BEAM OPTION Options include ELEMENT SET Purpose Apply the distributed traction load along any local axis of beam or a set of beams The local axes are defined in Figure 18 1 see also ELEMENT BEAM Card Format Type 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 18 2 LOAD LS DYNA3D Version 936 LOAD Figure 18 1 Applied traction
57. infinity LS DYNA3D 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 Abcissa value SFA Defined value OFFA Ordinate value SFO Defined value OF FO Positive offsets for the load curves DATTYP 0 are intended for time versus function curves since two additional points are generated automatically at time zero and at time 999 OFFO 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 DYNA3D 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 9 8 DEFINE LS DYNA3D Version 936 DEFINE DEFINE SD ORIENTATION Purpose Define orientation vectors for discrete springs and dampers Three alternative options are possible With the first two options 1 or 2 the vector is defined by coordi
58. locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector MANGLE Material angle may be overwritten on the element card AOPT 3 XP YP ZP Define coordinates of point p for AOPT 1 and 4 1 A2 Define components of vector a for AOPT 2 V1 V2 V3 Define components of vector v for AOPT 3 and 4 D1 D2 D3 Define components of vector d for AOPT 2 For the orthotropic definition it is referred to Material Type 2 and 21 LS DYNA3D Version 936 19 209 MAT MAT MAT CELLULAR RUBBER This is Material Type 87 This material model provides a cellular rubber model with confined air pressure combined with linear viscoelasticity as outlined by Christensen 1980 See Figure 19 24 Card Format Card 1 1 2 3 4 5 6 7 8 Variable Card 2 if N gt 0 a least squares fit is computed from unixial data Card Format Card 2 1 2 3 4 5 6 7 8 Type Card 2 if N 0 define the following constants Card Format Card 2 1 2 3 4 5 6 7 8
59. 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 interface segment file created in the first run should be specified using the L parameter on the LS DYNA3D 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 DYNA3D s analysis capabilities KEYWORD Flags LS DYNA3D that the input deck is a keyword 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 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 LS DYNA3D Version 936 1 15 INTRODUCTION INTRODUCTION MAT This section allows the defini
60. unlike the honeycomb model this material possesses no directionality but includes the effects of confined air pressure in its overall response characteristics sk air 9 ij 7 9 ij T 6 ij where oj is the skeletal stress and 6 is the air pressure computed from the equation ot _ Poy 1 where is the initial foam pressure usually taken as the atmospheric pressure and defines the volumetric strain y V where V is the relative volume defined as the ratio of the current volume to the initial volume and Yo is the initial volumetric strain which is typically zero The yield condition is applied to the principal skeletal stresses which are updated independently of the air pressure We first obtain the skeletal stresses sk air oj and compute the trial stress o kt oj At where E is Young s modulus Since Poisson s ratio is zero the update of each stress component is uncoupled and 2G E where G is the shear modulus The yield condition is applied to the principal skeletal stresses such that if the magnitude of a principal trial stress component oft exceeds the yield stress Oy then 19 136 MAT LS DYNA3D Version 936 MAT The yield stress is defined by 0 1 where b and c are user defined input constants is the volumetric strain as defined above After scaling the principal stresses they are transformed back into the global syst
61. where is the Chapman Jouguet relative volume and t is current time If F exceeds 1 it is reset to unity This calculation of the burn fraction usually requires several time steps for F to reach unity thereby spreading the burn front over several elements After reaching unity F is held constant 19 26 MAT LS DYNA3D Version 936 MAT MAT NULL This is Material Type 9 This material allows equations of state to be considered without computing deviatoric stresses Optionally a viscosity can be defined Also erosion in tension and compression is possible Sometimes it is advantageous to model contact surfaces via shell elements which are not part of the structure but are necessary to define areas of contact within nodal rigid bodies or between nodal rigid bodies Beams and shells that use this material type are completely bypassed in the element processing The Young s modulus and Poisson s ratio are used only for setting the contact interface stiffnesses and it is recommended that reasonable values be input Card Format Card 1 1 2 3 4 5 6 7 8 Variable TEROD CEROD Type Defaults VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density PC Pressure cutoff lt 0 0 MU Viscosity coefficient optional TEROD Relative volume hs for erosion in tension Typically use values greater 0 than unity If zero erosion in tension is inactive V R
62. 0 The number of VDA surfaces for which each point maintains actual distance information A global lower bound on distance is maintained for all remaining surfaces Whenever the point moves far enough to violate this global lower LS DYNA3D Version 936 L3 Appendix I converge 01 iterate 8 bound all VDA surfaces must have the global search performed for them Hence this parameter should be set to the maximum number of surfaces that any point can be expected to be near at one time the largest number of surfaces that come together at one point Setting ntrack higher will require more memory but result in faster execution If ntrack is too low performance may be unacceptably slow The default value is 4 0 When surface iterations are performed to locate the near point iteration is continued until convergence is detected to within this distance all VDA coordinates in mm The default value is 0 01 Maximum number of surface iterations allowed Since points being tracked are checked every cycle if convergence fails it will be tried again next cycle so setting this parameter high does not necessarily help much On the other hand a point converging to a crease in the VDA surface a crease between patches with discon tinuous derivative for example may bounce back and forth between patches up to this many times without actually moving Hence this value should not be too large The default value is 8 Example for
63. 0 rotation Frictional moment limiting value for rotation If zero friction is inactive for 0 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 4 6 Elastic stiffness per unit radian for friction and stop angles for y rotation See Figure 4 6 If zero friction and stop angles are inactive for y rotation 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 4 6 LS DYNA3D Version 936 4 15 CONSTRAINED CONSTRAINED VARIABLE DESCRIPTION NSAPH Stop angle in degrees for negative rotation Ignored if zero PSAPH Stop angle in degrees for positive rotation Ignored if zero NSAT Stop angle in degrees for negative 0 rotation Ignored if zero PSAT Stop angle in degrees for positive 0 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 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
64. 1 f s so Vp8 s so CA where K is a user defined constant or a tabulated function of the absolute value of the relative velocity Vp is the piston velocity C is the discharge coefficient Ap is the piston area Ab is the total open areas of orifices at time t Pfluid is the fluid density is the coefficient for the linear term and C is the coefficient for the quadratic term In the implementation the orifices are assumed to be circular with partial covering by the orifice controller The gradually shutdown as the piston closes of the orifice is properly taken into account If the piston stroke is exceeded the stiffness value defined by STF stops further movement The piston stroke must exceed the initial length of the beam element The time step calculation is also based on the stiffness value A typical force versus displacement curve at constant relative velocity is shown in Figure 19 17 19 176 MAT LS DYNA3D Version 936 MAT Figure 19 16 Mathematical model for the Side Impact Dummy damper LS DYNA3D Version 936 19 177 MAT MAT linear loading after orifices close f r c e last orifice closes force increases as orifice is gradually covered displacement Figure 19 17 Force versus displacement as orifices are covered at a constant relative velocity Only the linear velocity term is active 19 178 MAT LS DYNA3D Version 936 MAT MAT HYDRAULIC GAS DAMPER DISCRETE BEAM This is Mate
65. 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 LCID Load curve ID see DEFINE CURVE SF Load curve scale factor CID Coordinate system ID optional see remark 1 on next page 18 12 LOAD LS DYNA3D Version 936 LOAD VARIABLE DESCRIPTION MI Node 1 ID Only necessary if DOF EQ 4 see remark 2 below M2 Node 2 ID Only necessary if DOF EQ 4 see remark 2 below M3 Node 3 ID Only necessary if DOF EQ 4 see remark 2 below Remarks 1 The global coordinate system is the default The local coordinate system IDOs are defined in the DEFINE_COORDINATE_SYSTEM section 2 Nodes 1 2 must be defined for a follower force The follower force acts normal to the plane defined by these nodes as depicted in Figure 18 2 The positive t direction is found by the cross product t v w where v and w are vectors as shown t md m m 1 m V Figure 18 2 Follower force acting on plane defined by nodes mj m2 and In this case the load is applied to node mj i e m2m Positive force acts in the positive t direction LS DYNA3D Version 936 18 13 LOAD LOAD LOAD RIGID BODY Purpose Apply a concentrated nodal force to a rigid body The force is applied at the cener of mass or a moment is applied around
66. 1 s 0 T T homologous temperature room melt T room Constants for a variety of materials are provided in Johnson and Cook 1983 Due to nonlinearity in the dependence of flow stress on plastic strain an accurate value of the flow stress requires iteration for the increment in plastic strain However by using a Taylor series expansion with linearization about the current time we can solve for oy with sufficient accuracy to avoid iteration 19 42 MAT LS DYNA3D Version 936 MAT The strain at fracture is given by ef n Dy exp D3 1 0 Ine D where 6 is the ratio of pressure divided by effective stress oko E o eff Fracture occurs when the damage parameter B reaches the value of 1 LS DYNA3D Version 936 19 43 MAT MAT MAT PSEUDO TENSOR This is Material Type 16 This model has been used to analyze buried steel reinforced concrete structures subjected to implusive loadings Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 19 44 MAT LS DYNA3D Version 936 MAT Card 4 Card 5 Card 6 1 2 3 4 5 6 7 8 Card 7 LS DYNA3D Version 936 19 45 MAT MAT VARIABLE MID RO G PR SIGF AO Al A2 AOF AIF Bl PER ER PRR SIGY ETAN LCP LCR EPS ES DESCRIPTION Material identification A unique number has to be chosen Mass density Shear modulus Poisson s ratio Te
67. 154 MAT LS DYNA3D Version 936 MAT The shear relaxation behavior is described for the Maxwell model by G t Ga Go A Jaumann rate formulation is used oj 1 D x at V where the prime denotes the deviatoric part of the stress rate Oj and the strain rate Dij For the Kelvin model the stress evolution equation is defined as Goo ei sjt si E 1 5 Go 1 5 en j The strain data as given to LS TAURUS may be used to predict damage see Bandak 1991 LS DYNA3D Version 936 19 155 MAT MAT MAT VISCOUS FOAM This is Material Type 62 This model was written to represent the energy absorbing foam found on certain crash dummies This model was added to model the Confor Foam on the ribs of the Eurosid This model is only valid for solid elements mainly under compressive loading Card Format Card 1 1 2 3 4 5 6 7 8 pete fe fe e fw VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density El Initial Young s modulus E1 N1 Exponent in power law for Young s modulus n1 V2 Viscous coefficient V2 E2 Elastic modulus for viscosity E2 see notes below N2 Exponent in power law for viscosity n2 PR Poisson s ratio V The model consists of a nonlinear elastic stiffness in parallel with a viscous damper The elastic stiffness is intended to limit total crush while the viscosity absorbs energy The stiffness E exists to pr
68. 19 DATABASE DATABASE DATABASE TRACER Purpose Tracer particles will save a history of either a material point or a spatial point into an ASCII file TRHIST This history includes positions velocities and stress components The option DATABASE TRHIST must be active Card Format x SS VARIABLE DESCRIPTION TIME Start time for tracer particle TRACK Tracking option 0 particle follows material EQ 1 particle is fixed in space X Initial x coordinate X Initial y coordinate X Initial z coordinate 8 20 DATABASE LS DYNA3D Version 936 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 COORDINATE NODES DEFINE COORDINATE SYSTEM DEFINE COORDINATE VECTOR DEFINE CURVE DEFINE SD ORIENTATION DEFINE TABLE DEFINE VECTOR LS DYNA3D Version 936 9 1 DEFINE DEFINE DEFINE BOX Purpose Define a specific box shaped volume The two 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 Variable BOXID XMN Type Default Remarks VARIABLE DESCRIPTION BOXID Box ID Define unique numbers XMN Xmin coordinate XMX Xmax coordinate YMN Ymin coordinate YMX Y max coordinate ZMN Zmin coordin
69. 28 LOAD THERMAL VARIABLE NODE 1 1 eene eene nennen 18 30 itr 19 1 ELASTIC OPTION netter Ree eee es erepta 19 4 M AT OPTION TROPICLELAS TIC ee ely 19 7 MAT PEASTIC KINEMXATIC iter tentes EO ER TEE OES 19 13 MAT BEASTIC PEASTIC THERMAL ete tte to tette e eere tee eta te 19 16 MAT SOIL hee tg Dee EE Pr Perte ye i erras 19 19 TMAT VISCOBLEASLIC iere eh DINI UEM 19 23 MAT BLATZ KO RUBBER eie pter e EE ESPERE ERI ides 19 24 MAT HIGH EXPLOSIVE BURN nnne tenere 19 25 IMAT NUDD nter eet eR tiger i ere ed 19 27 MAT ELASTIC PLASTIC 19 29 MAT STEINBERG reete tps conde ethos ie yep e 19 32 MAT ISOTROPIC ELASTIC PLASTIC eene nene nennen 19 36 MAT ISOTROPIC ELASTIC cierre eere pr beret 19 37 MAT SOIL FOAM FAIEURE nitet eerie hA 19 39 MAT JOHNSON toreni Te Eor e eee t EE e et 19 40 SMAT PSEUDOCTENSOR tenete riore eget eee bet pecore eerte Ete terna 19 44 MAT ORIENTED CRACK 5 opere Ht 19 49 MAT POWEBR em 19 50 MAT STRAIN RATE DEPENDENT PLASTICITY ee
70. 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 LS DYNA3D Version 936 4 11 CONSTRAINED CONSTRAINED Cylindrical joint Planar joint Universal joint Translational joint Figure 4 4 Joint definitions 4 12 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED JOINT STIFFNESS OPTION Options include GENERALIZED FLEXION TORSION Purpose Define joint stiffness for joints defined by CONSTRAINED JOINT OPTION Card Format for both options 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 LS DYNA3D Version 936 4 13 CONSTRAINED CONSTRAINED Card Format 2 of 4 Required for GENERALIZED stiffness Card 2 LCIDPH LCIDT LCIDPS DLCIDPH DLCIDT DLCIDPS Default none none none none none none Card Format 3 of 4 Required for GENERALIZED stiffness Card 3 3 4 5 6 Card Format 4 of 4 Required for GENERALIZED stiffness Card 4 NSAPH PSAPH NSAPS PSAPS 4 14 CONSTRAINED LS DYNA3D Version 936 VARIABLE LCIDPH LCIDT LCIDPS DLCIDPH DLCIDT DLCIDPS ESPH FMPH EST F
71. 936 MAT MAT SPRING INELASTIC This material allows to simulate an onelastic tension or compression only translational or rotational spring Optionally a user specified unloading stiffness can be taken instead of the maximum loading stiffness Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIPTION MID Material identification A uniques number has to be chosen LCFD Load curve identification describing arbitrary force torque versus displacement twist relationship This curve must be defined in the positive force displacement quadrant regardless of whether the spring acts in tension or compression KU Unloading stiffness optional If zero the maximum loading stiffness in the force displacement resp moment twist curve is used CTF Flag for compression tension EQ 1 0 tension only EQ 0 0 default is set to 1 0 EQ 1 0 compression only LS DYNA3D Version 936 19 227 MAT MAT MAT SEATBELT Purpose Define seat belt material See notes below Card Format Card 1 1 2 3 4 5 6 7 8 Variable MID LLCID ULCID Type Default VARIABLE DESCRIPTION MID Belt material number A unique number has to be chosen MPUL Mass per unit length LLCID Load curve identification for loading strain force with engineering strain ULCID Load curve identification for unloading strain force with engineering strain LMIN Minimum length for elements connected to slip rings and retractors see notes below
72. AS viscosity identification defined in the HOURGLASS ection EQ 0 default values are used GRAV Part initialization for gravity loading EQ 0 all parts initialized EQ 1 only current material initialized ADPOPT Indicate if this part is adapted not see also CONTROL_ADAPTIVITY EQ 0 no adaptivity EQ 1 yes LS DYNA3D Version 936 21 3 PART PART VARIABLE TMID XC YC ZC TM IRCS IXX IXY IYY IYZ LZ VTX VTY VTZ VRX VRY ZL 21 4 PART DESCRIPTION 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 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 principal moments of inertia with orientation vectors Ixx xx component of inertia tensor Ixy set to zero if IRCS 1 set to zero if IRCS 1 Iyy yy component of inertia tensor set to zero if IRCS 1 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
73. CONSTRAINED CONSTRAINED 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 fillet weld may occur gradually with first one node failing and later the second node may fail 4 6 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED 2 NODE SPOTWELD 3NODE SPOTWELD node 1 n NODE SPOTWELD Figure 4 1 Nodal ordering and orientation of the local coordinate system is important for determining spotweld failure LS DYNA3D Version 936 4 7 CONSTRAINED CONSTRAINED local coordinate system 2 NODE FILLET WELD 3NODE FILLET WELD Figure 4 2 Nodal ordering and orientation of the local coordinate system is shown for fillet weld failure The angle is defined in degrees 4 8 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED 2 tied nodes that can FA d pe be coincident 2 tied nodi L y 4 tied nodig Figure 4 3 Orientation of the local coordinate system and nodal ordering is shown for butt weld failure LS DYNA3D Version 936 4 9 CONSTRAINED CONSTRAINED CONSTRAINED JOINT OPTION Options include SPHERICAL REVOLUTE CYLINDRICAL PLANAR UNIVERSAL TRANSLATIONAL Purpose Define a joint between two rigid bodies see Figure 4 4 Card Format 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
74. Card 5 1 2 3 4 12 8 EOS LS DYNA3D Version 936 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 DYNA3D Version 936 12 9 EOS EOS VARIABLE DESCRIPTION EOSID Equation of state ID 10 All A12 A13 A20 A2 A22 A23 A30 A31 A32 A33 A40 AAT A42 A43 A50 AS A52 A53 A60 A61 A62 A63 A70 A71 12 10 EOS LS DYNA3D Version 936 EOS VARIABLE DESCRIPTION A72 73 14 24 ALPHA p E0 Initial internal energy vo Initial relative volume The ratio of polynomials equation of state defines the pressure as RO KR E 1 og F F E where n 3ifiz3 Po In expanded elements Fj is replaced by D u 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 DYNA3D Version 936 12 11 EOS EOS EOS LINEAR POLYNOMIAL WITH ENERGY LEAK Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Type VARIABLE DESCRIPTION EOSID Equation of state label CO Cl C2 C3 C4 C5 C6 E0 Initial internal energy vo Initial relative volume LCID Load curve ID defining the energy deposition rate 12 12 EOS LS DYNA3D Version 936 EOS EOS IGNITION AND GROWTH OF REACTION IN HE Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 VARIABLE DESCRIPTION EOSID Eq
75. 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 only for TRANSLATIONAL joints N6 Node 6 in rigid body B Define only for TRANSLATIONAL joints 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 4 10 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED With one exception 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 The geometry of joints is defined in Figure 4 4 Insofar as the penalty method is used 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 penalty stiffness 1s too large If instabilities occur the recommended way to eliminate these problems is to decrease the time step For cylindrical joints by setting node
76. ID option SET see SET NODE of added nodes This option allows the definition of additional nodes with extra masses loads or anything else to be constrained to a rigid body such as joints The extra nodes can be defined at any location and are assumed to be part of the rigid body The coordinates of the extra nodes are updated according to the rigid body motion 4 2 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED GENERALIZED WELD OPTION Then the following options are available SPOT FILLET BUTT Purpose Define spot and fillet welds Coincident nodes are permitted Card Format Variable Default Additional Card required for the SPOT option Card 2 1 2 3 4 5 6 7 8 m fefee Additional Card required for the FILLET option Card 2 1 2 3 4 5 6 7 8 Variable TFAIL EPSF SIGY BETA ALPHA LS DYNA3D Version 936 4 3 CONSTRAINED CONSTRAINED Additional Card required for the BUTT option Card 2 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 TFAIL Failure time for constraint set tf default 1 E 20 EPSF Effective plastic strain at failure en il defines ductile failure SN Sn normal force at failure only for the brittle failure of spotwelds SS Ss shear force at failure only for the brittle failure of spotwelds N n exponent for normal force only for the
77. 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 DYNA3D Version 936 29 7 RESTART RESTART VARIABLE PSIDMN LCVMNX DIR VID BIRTH DEATH DESCRIPTION Optional 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
78. INTERFACES The three dimensional contact impact algorithm was originally an extension of the NIKE2D Hallquist 1979 two dimensional algorithm 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 DYNA3D 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 surf
79. Initialize all discrete parts from the old parts No further input is required with this card This card is not required if SSTRESS INITIALIZATION 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 SSTRESS INITIALIZATION is specified without further input 29 34 RESTART LS DYNA3D Version 936 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 T
80. NODE and CON STRAINED ADAPTIVITY to be saved in the file adapt msh 6 2 CONTROL LS DYNA3D Version 936 CONTROL output periods mmm s endtime tdeath Figure 6 1 At time ibirth the adaptive calculation begins After computing for a time interval adpfreq error norms are computed and 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 again computed The mesh that existed at time tbirtht adpfreq is refined and the calculation continues to time tbirth 3 x adpfreq and so on LS DYNA3D Version 936 6 3 CONTROL CONTROL CONTROL ALE Purpose Set default control parameters for the Arbitrary Lagrange Eulerian calculations See also SECTION SOLID ALE and ALE SMOOTHING Card Format Card 1 1 2 3 4 5 6 7 8 Variable Default Card 2 1 2 3 4 5 6 7 8 Default 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 first order accuracte EQ 2 Van Leer half index shift EQ 3 Van Leer default AFAC Smoothing weight factor Simple average EQ 1 turn smoothing off 6 4 CONTROL LS DYNA3D Version 936 CONTROL VARIABLE DESCRIPTION BFAC Smoothing weight factor V
81. No thermal contact if gap is greater than this value LS DYNA3D Version 936 VARIABLE SOFT SOFSCL LCIDAB MAXPAR PENTOL DEPTH BSORT FRCFRQ PENMAX THKOPT CONTACT DESCRIPTION Soft constraint option EQ 0 penalty formulation EQ 1 soft constraint formulation Necessary if a surface in contact has wildly varying stiffnesses along surface 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 Load curve ID defining airbag thickness as a function of time for type a13 contact CONTACT AIRBAG SINGLE SURFACE 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 factor allows an increase in the size of the segments May be useful at sharp corners Special penetration tolerance not currently used Search depth in automatic contact Value of 1 is sufficiently accurate for most crash applications and is much less expensive LS DYNA3D for improved accuracy sets this value to 2 If zero the default is set to 2 Number of cycles between bucket sorts Values of 25 and 100 are recommended 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 DYNA3D determines the interval Numbe
82. ROTATIONAL ACCELERATIONS ABOUT THE LOCAL XYZ AXES TIME IS THE CURRENT TIME DT1 IS TIME STEP SIZE AT N 1 2 DT2 IS TIME STEP SIZE AT N 1 2 PARAM IS USER DEFINED INPUT PARAMETERS MAX 25 HIST IS USER DEFINED HISTORY VARIABLES MAX 25 ITRNON IS FLAG TO TURN ON THE AIRBAG INFLATION RBUG RBVG RBAG ARE SIMILAR TO RBU RBV RBA BUT ARE DEFINED GLOBALLY THE USER SUBROUTINE SETS THE VARIABLE ITRNON TO ITRNON 0 BAG IS NOT INFLATED ITRNON 1 BAG INFLATION BEGINS AND THIS SUBROUTINE IN NOT CALLED AGAIN QQQQ000000000000000000no00o0o0o0n0nqnQqnp DIMENSION RBU 6 RBV 6 PARAM 25 HIST 25 RBUG 6 RBVG 6 RBAG 6 RETURN END LS DYNA3D Version 936 B 1 Appendix C APPENDIX C User Defined Solution Control This subroutine may be provided by the user to control the I O monitor the energies and other solution norms of interest and to shut down the problem whenever he pleases The arguments are defined in the listing provided below This subroutine is call each time step and does not need any control card to operate SUBROUTINE UCTRL1 TIME DT1 DT2 PRTC PLTC FRCI PRTO PLTO FRCO VT VR AT AR UT UR XMST XMSR IRBODY RBDYN USRHV MESSAG TOTALM CYCL IDRINT CER KKK e Fe He e e e e e Fe e e KKK e e e e e e e e e e He He eee hehehe hehe hehehe He He ke e He ke ke He ke kk ke ke ke ke ke k k C LIVERMORE SOFTWARE TECHNOLOGY CORPORATION LSTC Qoo See ese E C COPYRIGHT 1987 19
83. Rayleigh stiffness damping coefficient by part set ID Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID see PART and SET_PART BETA Rayleigh damping coefficient for stiffness weighted damping The damping matrix in Rayleigh damping is defined as BK where M and damping mass stiffness matrices respectively The constants 04 and p are the mass and stiffness proportional damping constants The mass proportional damping be treated by system damping in LS DYNA3D see Control Card 14 Columns 1 5 Transforming C with the ith eigenvector gives 1C 0 aM BK a 206 jj where is the ith frequency radians unit time and is the corresponding modal damping parameter If 10 of critical damping is sought in the ith mode using stiffness proportional damping then set 7 4 DAMPING LS DYNA3D Version 936 DAMPING 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 LS DYNA3D Version 936 7 5 DAMPING DATABASE DATABASE The database defintions 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 SECTI
84. To make the coupled program run an input deck must be provided to both the OSP and LS DYNA3D The two input decks must be provided in the same set of consistent units This can potentially require a major conversion to either the OSP input or the LS DYNA3D input With two legitimate and consistent input decks the coupled program should run to completion with no problems Additional inputs are required to make the models interact between the OSP and LS DYNAJ3D portions of the run The simplest form of a coupled simulation is simply to include a single body in an OSP run No special modifications are needed to the OSP input deck for use in the coupled simulation Ellipsoids and planes in the OSP are usually attached to segments which correspond to LS DYNA3D rigid bodies Because the coupling procedure works on the basis of shared information on LS DYNAS3D rigid bodies with the OSP segments the ellipsoids planes listed in the OSP section must correspond to the segments which are to be coupled These ellipsoids and planes LS DYNA3D Version 936 F3 Appendix F may be actual geometry which is used for contact or they may be simply artificial shapes to permit the data transfer between the OSP and LS DYNA3D DUMMY MODELING The dummy is typically modeled entirely within the OSP The coupling of the dummy into LS DYNA3D requires the creation of a separate LS DYNA3D rigid body material for each segment of the OSP The easiest way to create a mesh fo
85. 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 DYNA3D Version 936 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 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 Variable PARM2 PARM3 PARM4 5 PARM6 PARM7 Default none none none none none none VARIABLE DESCRIPTION PARMn This is the nth user input parmeter LS DYNA3D Version 936 28 3 USER RESTART RESTART INPUT DATA In general three categories of restart actions are possible with LS DYNAS3D and are outlined in the following discussion a b A simple restart occurs when LS DYNA3D was interactively stopped before reaching the termination time Then simply defining the R rtf file on the execution line for LS DYNA3D r
86. VECTOR Purpose Define a vector with the coordinates of two nodes Card Format Variable Type Default Remarks 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 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 9 12 DEFINE LS DYNA3D Version 936 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 MAT_RIGID in the input are permanently rigid and cannot be changed to deformable Deformable parts may be switched to rigid at the start of the calculation by specifying them on the DEFORMABLE TO 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 swit
87. Whirley R G J O Hallquist and G L Goudreau An Assessment of Numerical Algorithms for Plane Stress and Shell Elastoplasticity on Supercomputers Engineering Computations Vol 6 pp 116 126 1989 Wilkins M L R E Blum E Cronshagen and P Grantham A Method for Computer Simulation of Problems in Solid Mechanics and Gas Dynamics in Three Dimensions and Time University of California Lawrence Livermore National Laboratory Rept UCRL 51574 1974 Woodruff J P KOVEC User s Manual University of California Lawrence Livermore National Laboratory Rept UCRL 51079 1973 30 6 REF LS DYNA3D Version 936 Appendix A APPENDIX A User Defined Materials The addition of user material subroutine into LS DYNA3D is relatively simple A keyword MAT USER DEFINED MATERIAL MODELS is required on which each user subroutine referenced The number of history variables is arbitrary and can be any number greater than or equal to 0 The coordinate system definition is optional but is probably necessary if the model involves material that have directional properties such as composites and anisotropic plasticity models When the coordinate system option is used then all data passed to the constitutive model is in the local system A bulk modulus and shear modulus are required for transmitting boundaries contact interfaces rigid body constraints and time step size calculations The number of constants read in columns 6 10 incl
88. YC ALPH LS DYNA3D Version 936 MAT DESCRIPTION Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector EQ 4 0 locally orthotropic in cylindrical coordinate system with the material axes determined by a vector v and an orginating point P They define the axis of symmetry Material axes change flag for brick elements EQ 1 0 default EQ 2 0 switch material axes a and b EQ 3 0 switch material axes a and c Coordinates of point p for AOPT 1 Components of vector a for AOPT z 2 Components of vector v for AOPT 3 Components of vector d for AOPT 2 Shear strength ab plane see Theoretical Manual Longitudinal tensile strength a axis see Theoretical Man
89. a global axis As an option local axes can be defined for force or moment directions Card Format 1 2 3 4 5 6 7 8 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 LCID Load curve ID see DEFINE CURVE SF Load curve scale factor CID Coordinate system ID MI Node 1 ID Only necessary if DOF EQ 4 see remark 2 on next page M2 Node 2 ID Only necessary if DOF EQ 4 see remark 2 on next page M3 Node 3 ID Only necessary if DOF EQ 4 see remark 2 on next page 18 14 LOAD LS DYNA3D Version 936 LOAD Remarks 1 The global coordinate system is the default The local coordinate system IDOs are defined in the DEFINE COORDINATE SYSTEM section This local axis is fixed in inertial space i e it does not move with the rigid body 2 Nodes Mj M2 M3 must be defined for a follower force The follower force acts normal to the plane defined by these nodes as depicted in Figure 18 2 The positive t direction is found by the cross product t v xw where v and w are vectors as shown The follower force is applied at the center of mass LS DYNA3D Version 936 18 15 LOAD LOAD LOAD SEGMENT Purpose Apply the distributed pre
90. a structural only analysis They are ignored in a thermal only or coupled thermal structural analysis see CONTROL THERMAL OPTION All 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 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 DYNA3D Version 936 18 23 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 7 8 NSID NSIDEX BOXID Card 2 1 2 3 4 5 6 7 8 i VARIABLE DESCRIPTION NSID Nodal set ID containing nodes for initial temperature see SET NODES EQ 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 initializ
91. 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 29 18 RESTART LS DYNA3D Version 936 RESTART CONTROL TERMINATION Purpose Stop the job Card Format 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 LS DYNA3D Version 936 29 19 RESTART RESTART CONTROL TIMESTEP Purpose Set time step size control using different options Card Format 1 2 3 4 5 6 7 8 fete see 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 EQ 0 characteristic length area longest side EQ 1 characteristic length area longest diagonal EQ 2 based on bar wave speed and MAX short
92. added to the physical stresses at the local element level The discussion of the hourglass control that follows pertains to all one point quadrilateral shell and membrane elements in LS DYNA3D 13 2 HOURGLASS LS DYNA3D Version 936 HOURGLASS The hourglass shape vector tj is defined as A58 Bay 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 the 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 Sr 811 227 81 31 The hourglass shape vector then operates on the generalized displacements to produce the generalized hourglass strain rates M qa 717 B A da 19 W _ 43 T Vq where the superscripts M B and W denote membrane bending and warping modes respectively The corresponding hourglass stress rates are then given by QM EtA ay Qa 8 3 p xg QW KGt A 12 1 143 where t is the shell thickness The hourglass coefficients and QW are generally assigned values between 0 05 and 0 10 LS DYNA3D Version 936 13 3 HOURGLASS HOURGLASS Finally the hourglass stresses which are updated using the time step Ar from the stress rates in the
93. and submerged structures where the gravitational preload is important Only one load curve and direction is permitted If multiple cards are used LCID and DIR should not change Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part set ID see PART or SET PART OPTION 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 DEFINE CURVE 18 10 LOAD LS DYNA3D Version 936 LOAD LOAD HEAT GENERATION OPTION Available options are SET SOLID Purpose Define solid elements or solid element set with heat generation Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SID Solid element set ID or solid element ID see SET SOLID or ELEMENT_SOLID respectively LCID Load curve ID for volumetric heat generation rate 4 GT 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 LS DYNA3D Version 936 18 11 LOAD LOAD LOAD NODE OPTION Options include POINT SET Purpose Apply a concentrated nodal force to a node or a set of nodes Card Format Variable NODE NSI DOF D VARIABLE DESCRIPTION NODE NSID Node ID or nodal set ID NSID see SET NODE OPTION DOF Applicable degrees of freedom EQ
94. 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 Olocking up characteristic in the force pullout curve see Figure 11 3 The final section can be very steep but must have a finite slope 11 14 ELEMENT LS DYNA3D Version 936 ELEMENT Element 1 Before Elemen s i Element 3 Element 1 Element 2 After Hlement Js Element 4 All nodes within this area are coincident Figure 11 2 Elements in a retractor LS DYNA3D Version 936 11 15 ELEMENT ELEMENT with weblockers without weblockers PULLOUT Figure 11 3 Retractor force pull characteristics 11 16 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SEATBELT SENSOR Purpose Define seat belt sensor Four types are possible see explanation below Card Format Type Remarks Default LS DYNA3D Version 936 11 17 ELEMENT ELEMENT Second Card if SBSTYP 2 1 2 3 Variable SBRID PULRAT PULTIM Type Default Remarks
95. as density and Young s Modulus A crash model can consist of 100 or more separate materials which are each assigned a material number and each materia number has an associated material type which determines if it is elastic plastic viscoelastic orthotropic etc The material type may also specify that it is a rigid body In this case all elements of the same material number are treated as a single rigid body These elements are integrated to determine the mass centroid and moments of inertia for the group This group is then treated as a rigid body with six degrees of freedom including three translations and three rotations The positions of the rigid bodies are updated in LS DYNA3D by a time integrator which works together with the central difference time integration There is an additional flag which specifies that the LS DYNA3D rigid body is coupled to an OSP rigid body This flag can be found in the description of the rigid body material MAT RIGID formerly material type 20 In coupled updates the OSP rigid body time integrator takes over control of the LS DYNA3D rigid body and the normal LS DYNA3D updates are bypassed The time integration procedure is then as follows F 2 LS DYNA3D Version 936 Appendix F 1 At the beginning of a step LS DYNA3D determines the locations and updates the positions of all of the rigid bodies which are coupled to the OSP This information is obtained from common block information in the OSP 2
96. asin 17 6 On 18 1 LOAD BEAM OPTION 55 sautadeveduacegbausbedubevencessauenldy 18 2 LOAD BODY QBTION iet rtt ee ee eee ee E E S 18 4 LOAD BODY GENERALIZED 5 nne hore dre rH i ee EP P RR Pr 18 6 LOAD 18 8 LOAD2 DENSITY DEPTH er rt E EE One HERE esi Reo ERE 18 10 LOAD HEAT GENERATION 18 11 EOAD NODE OPTION 1n t t RR 18 12 LOAD RIGID BODY ain 18 14 LOAD SEGMEN e etm ER Hte Eee SERT ERR TES ERN ERAT Eo HERE hts 18 16 LOAD SEGMENT SET ttt ee e e estt ee uut eve AUR eee 18 17 SEQAD SHELE OPTION 42 htt eR PPAR GEO e net 18 19 LS DYNA3D Version 936 V TABLE OF CONTENTS LOAD SUPERPLASTIC FORMING n terree eer 18 20 LOAD THERMAL OPTION eic tete ter eh eite te eo hr ob tienden 18 23 LOAD THERMAL CONS TANT ieri eret pere et ei e PEE 18 24 LOAD THERMAL CONSTANT 02 18 25 LOAD THERMAL ue P RE eR Cri bei tis 18 26 SELOADZLHERMATL TOPAZ noH tied iach Ande ee a dee 18 27 LOAD THERMAL VARIABLE iit pertice rt vo ded 18
97. been fitted to one and two dimensional shock initiation and detonation data for four explosives PBX 9404 RX 03 BB PETN and cast TNT The details of the calculational method are described by Cochran and Chan 1979 The detailed one dimensional calculations and parameters for the four explosives are given by Lee and Tarver 1980 LS DYNA3D Version 936 12 15 EOS EOS EOS TABULATED COMPACTION Card Format Card 1 1 2 3 4 5 6 7 8 Variable EOSID GAMA Type Card Format 5E16 0 Card 2 1 2 3 4 5 Variable Type Card 3 Variable Type Repeat Cards 2 and 3 for Cj 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 12 16 EOS LS DYNA3D Version 936 EOS VARIABLE DESCRIPTION GAMA y EO Initial internal energy VO Initial relative volume The tabulated compaction model is linear in internal energy Pressure is defined by p C ey gT ey E in the loading phase The volumetric strain y 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 12 1 Up to 10 points and as few as 2 may be used when defining the tabulated functions LS DYNA3D will extrapolate to find the pressure if necessary L
98. bodies SNLOG Disable shooting node logic in thickness offset contact EQ 0 logic is enabled default EQ 1 logic is skipped sometimes recommended for metal forming calculations 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 master set ID is not defined for the single surface contact algorithms The draw bead is defined by a consecutive list of 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 5 16 CONTACT LS DYNA3D Version 936 CONTACT D depth of draw bead F Foending Figure 5 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 LS DYNA3D Version 936 5 17 CONTACT CONTACT INTERF
99. by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector Coordinates of point p for AOPT 1 Components of vector a for AOPT 2 Components of vector v for AOPT 3 Components of vector d for AOPT 2 LS DYNA3D Version 936 MAT Remarks 1 The compression option allows the simulation of airbag inflation with far less elements than would be needed for the discritization of the wrinkles which would occur for the case when compressive stresses are not eliminated 2 When using this material for the analysis of membranes as airbags it is well known from classical theory that only one layer has to be defined The so called elastic liner has to be defined for numerical purposes only when the no compression option is invoked LS DYNA3D Version 936
100. by the current volume The pressure is uniformly applied to the control volume 1 18 AIRBAG LS DYNA3D Version 936 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 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 0 0 IAREAI is the load curve ID defining the orifice area as a function of absolute pressure SF Shape factor LT 0 0 ISFI is the load curve ID defining vent orifice coefficient as a function of relative time This input is valid for the following airbag types AIRBAG SIMPLE AIRBAG MODEL AIRBAG WANG NEFSKE AIRBAG WANG NEFSKE JETTING AIRBAG WANG NEFSKE MULTIPLE JETTING The airbags must contain the same gas 1 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 DYNA3D Version 936 1 19 AIRBAG AIRBAG AIRBAG REFERENCE GEOMETRY Purpose If the reference configuration of the airbag is 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 fo
101. c aor 0 ajf 0 385 where ucf ag is a unit conversion factor for f psi DYNA pressure unit A zero equation of state number can also be specified in this case and data for a tri linear E088 model good for pressures below approximately 5 kbars will be generated internally using the values given for Poisson s ratio and f c Otherwise Equation of State 8 9 or 11 must be specified and the corresponding data provided by the user Principal material and reinforcement properties are combined using a rule of mixtures as follows bulk 1 fs bkm fs bkr shrm 1 fs gm fs gr sigy 1 fs sym fs syr where sym f k1 edot a0 p al a2 p g dmg or f kl edot g p and syr f k2 edot qs qh epx f k edot denotes the yield stress strain rate scaling factor obtained by linear interpolation from load curve k if k 0 f 1 0 and g denotes either the damage or pressure scaling factor obtained by linear interpolation from the yield stress table dmg is an isotropic measure of damage defined as dmg 0 CE Jes sigf LS DYNA3D Version 936 19 47 MAT MAT fs is the percent reinforcement which is treated isotropically If the maximum principal stress in an element exceeds the tensile cutoff the matrix material in that element is assumed to have fractured After fracture the matrix material in an element can support only compressive loads and its shear strength is limited by the yield surface for f
102. coefficient Coefficient for fluid inertia term k stiffness coefficient if piston bottoms out P fluid fluid density coefficient for linear velocity term Co coefficient for quadratic velocity term Load curve number ID defining force versus piston displacement s i e term s 50 Compressive behavior is defined in the positive quadrant of the force displacement curve Displacements falling outside of the defined force displacement curve are extrapolated Care must be taken to ensure that extrapolated values are reasonable Load curve number ID defining damping coefficient versus piston displacement s i e g s 59 Displacements falling outside the defined curve are extrapolated Care must be taken to ensure that extrapolated values are reasonable Initial displacement so typically set to zero A positive displacement corresponds to compressive behavior d orifice location of ith orifice relative to the fixed end orifice radius of ith orifice if zero the default radius is used LS DYNA3D Version 936 19 175 MAT MAT As the damper moves the fluid flows through the open orifices to provide the necessary damping resistance While moving as shown in Figure 19 16 the piston gradually blocks off and effectively closes the orifices The number of orifices and the size of their opening control the damper resistance and performance The damping force is computed from 2 1 CV p fuia E
103. coincident with the retractor node but should not be inside the retractor 3 At least one sensor should be defined The first point of the load curve should be 0 Tmin Tmin is the minimum tension All subsequent tension values should be greater than 5 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 1 2 3 A 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 11 12 ELEMENT LS DYNA3D Version 936 ELEMENT In the unlocked regime the retractor attempts to apply a constant tension to the belt 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 constan
104. defined by load curve n VALDMP System damping constant d this option is bypassed if the load curve number defined above is nonzero LS DYNA3D Version 936 7 1 DAMPING DAMPING Remark 1 This keyword is also used for the restart see RESTART With system damping the acceleration is computed as a u pups F where is the diagonal mass matrix P is the external load vector F is the internal load vector and F dapib is the force vector due to system damping This latter vector is defined as n damp 7 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 FD D 20 min is recommended where the natural frequency given in radians per unit time is generally taken as the fundamental frequency of the structure 7 2 DAMPING LS DYNA3D Version 936 DAMPING DAMPING PART MASS Purpose Define mass weighted damping by part set ID Card Format 1 2 3 4 3 6 7 8 VARIABLE DESCRIPTION PID Part ID see PART and SET 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 Mass weighted damping damps all motions including rigid body motions For oscillatory motion stiffness weighted damping is preferred LS DYNA3D Version 936 7 3 DAMPING DAMPING DAMPING PART STIFFNESS Purpose Assign
105. 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 1 are unchanged in e2 they are set equal to those in el The retractor now pays out material into e2 LS DYNA3D Version 936 11 13 ELEMENT ELEMENT 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 Omouth element into which belt material will be fed 1 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 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 element 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
106. defining the yield stress as a function of the effective strain rate 19 52 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION ETAN Plastic hardening modulus LC2 Load curve ID defining Young s modulus as a function of the effective strain rate optional LC3 Load curve ID defining tangent modulus as a function of the effective strain rate optional LC4 Load curve ID defining von Mises stress at failure as a function of the effective strain rate optional TDEL Minimum time step size for automatic element deletion Use for shells only In this model a load curve is used to describe the yield strength og as a function of 3 ijt ij and the prime denotes the deviatoric component The yield stress is defined as effective strain rate E where 0 00 Ep where is effective plastic strain and Ep is given by EE Ej LS DYNA3D Version 936 19 53 MAT MAT MAT RIGID This is Material 20 Parts made from this material are considered to belong to a rigid body for each part ID Also the coupling of a rigid body with MADYMO and CAL3D can be defined via this material Alternatively a VDA surface can be attached as surface to model the geometry e g for the tooling in metalforming applications Also global and local constraints on the mass center can be optionally defined Optionally a local consideration for output and user defined airbag sensors can be chosen
107. direction initial 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 x coordinate of local x axis Origin lies at 0 0 0 y coordinate of local x axis z coordinate of local x axis LS DYNA3D Version 936 PART VARIABLE XLIP YLIP ZLIP CMSN MDEP MOVOPT Remarks DESCRIPTION x coordinate of local in plane vector y coordinate of local in plane vector z coordinate of local in plane vector CAL3D segment number MADYMO system number See the numbering in the corresponding program MADYMO ellipse plane number GT 0 ellipse number EQ 0 default LT 0 absolute value is plane number 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 EQ 0 merged rigid body is repositioned EQ 1 merged rigid body is not repositioned 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 2 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 comput
108. displacement magnitude of the centre of mass is exceeded stop 4 If more than one condition is input the analysis stops when any of the conditions is satisfied Termination by other means is controlled by the CONTROL TERMINATION control card Note This type of termination is not active during dynamic relaxation LS DYNA3D Version 936 25 1 TERMINATION TERMINATION Card Format Default For the NODE option 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 For the BODY option VARIABLE DESCRIPTION PID Part ID of rigid body see 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 25 2 TERMINATION LS DYNA3D Version 936 TITLE TITLE Purpose Define job title Card Format Variable LS DYNA3D USER INPUT VARIABLE DESCRIPTION TITLE Heading to appear on output and in output files
109. for y versus a scale factor which scales the bending moment due to the amp rotation This load curve should be defined in the interval 7 Y lt 7 If zero the scale factor defaults to 1 0 See DEFINE CURVE Load curve ID for B torsion moment versus twist in radians If zero the applied twist is set to zero See DEFINE CURVE Load curve ID for damping moment versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE 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 Load curve ID for B damping torque versus rate of twist If zero damping is not considered See DEFINE CURVE Elastic stiffness per unit radian for friction and stop angles for rotation see Figure 4 7 If zero friction and stop angles are inactive for 04 rotation Frictional moment limiting value for rotation If zero friction is inactive for amp 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 4 7 Elastic stiffness per unit radian for friction and stop angles for D twist see Figure 4 7 If zero friction and stop angles are inactive for B twist Frictional moment limiting value for twis
110. heating cause material softening Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 19 40 MAT LS DYNA3D Version 936 MAT Card 4 Variable Type Default VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus E Young s Modulus shell elements only PR Poisson s ratio shell elements only DTF Minimum time step size for automatic element deletion shell elements A See equations below B See equations below N See equations below C See equations below M See equations below TM Melt temperature TR Room temperature EPSO Effective plastic strain rate CP Specific heat PC Failure stress or pressure cutoff pmin lt 0 0 LS DYNA3D Version 936 19 41 MAT MAT VARIABLE DESCRIPTION SPALL Spall type EQ 0 0 default set to 2 0 EQ 1 0 gt Pmin EQ 2 0 if Omax 2 pmin element spalls and tension p lt 0 is never allowed EQ 3 0 p lt pmin element spalls and tension p lt 0 is never allowed IT Plastic strain iteration options EQ 0 0 no iterations default EQ 1 0 accurate iterative solution for plastic strain Much more expensive than default D1 D5 Failure parameters see equations below Johnson and Cook express the flow stress as ines where A B C n and m input constants EP effective plastic strain P 22 28 E effective plastic strain rate for 9
111. high strain rates 210 and can be used with solid elements The yield strength is a function of temperature and pressure An equation of state is determines the pressure Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 Card 4 19 32 MAT LS DYNA3D Version 936 VARIABLE MID RO GO SIGO BETA GAMA SIGM BP TMO GAMO SA PC SPALL FLAG LS DYNA3D Version 936 MAT DESCRIPTION Material identification A unique number has to be chosen Mass density Basic shear modulus Oo see defining equations D see defining equations n see defining equations initial plastic strain see defining equations Om see defining equations b see defining equations b see defining equations h see defining equations f see defining equations Atomic weight if 0 0 R must be defined Tmo see defining equations Yo see defining equations a see defining equations Pmin OF Of Spall type EQ 0 0 default set to 2 0 EQ 1 0 p gt EQ 2 0 if Omax 2 pmin element spalls and tension p lt 0 is never allowed EQ 3 0 p lt pmin element spalls and tension p lt 0 is never allowed R Z0 0 A is not defined Set to 1 0 for coefficients for the cold compression energy fit Default is 1 19 33 MAT MAT VARIABLE DESCRIPTION MMN Umin Nmin Optional u or minimum value MMX Umax Nmax Optional u or n maximum value
112. in formulations with Model 27 we find that the results obtained with this model are nearly identical with those of Material 27 as long as large values of Poisson s ratio are used 19 196 MAT LS DYNA3D Version 936 MAT MAT SOIL CONCRETE This is Material Type 78 This model permits concrete and soil to be efficiently modelled See the explanations below Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type Card 2 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus K Bulk modulus LCPV Load curve ID for pressure versus volumetric strain The pressure versus volumetric strain curve is defined for compression only The sign convention requires that both pressure and compressive strain be defined as positive values where the compressive strain is taken as the negative value of the natural logrithm of the relative volume LCYP Load curve ID for yield versus pressure GT 0 von Mises stress versus pressure LT 0 Second stress invariant Jo versus pressure LCFP Load curve ID for plastic strain at which fracture begins versus pressure LS DYNA3D Version 936 19 197 MAT MAT VARIABLE DESCRIPTION LCRP Load curve ID for plastic strain at which residual strength is reached versus pressure PC Pressure cutoff for tensile fracture OUT Output option for plastic strain in database EQ 0 volumetric plastic strain
113. 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 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 The optional definition of part sets in minimum or maximum coordinate direction allows the motion to be controlled in arbitrary direction LS DYNA3D Version 936 4 33 CONSTRAINED CONSTRAINED D Te NU RIGID BODY STOPPER Figure 4 9 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 D and D respectively c g center of gravity 4 34 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED RIVET Purpose Define massless rivets between non contiguous nodal pairs The nodes must not have the same coordinates The action is such
114. 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 Odrift before the pretensioner is activated To activate the pretensioner the following sequence of events must occur 1 Anyone of up to four sensors must be triggered 2 Then user defined time delay occurs 3 Then the pretensioner acts 11 10 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SEATBELT RETRACTOR Purpose Define seat belt retractor Card Format SBRID SBRNID SBID SID3 SIDA Second Card TDEL PULL LLCID ULCID VARIABLE DESCRIPTION SBRID Retractor ID Use consecutive numbering see below SBRNID Retractor node ID SBID Seat belt element ID SID1 Sensor ID 1 LS DYNA3D Version 936 11 11 ELEMENT 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 between time delay ending and retractor locking a length value LLCID Load curve for loading Pull out Force see Figure 11 3 ULCID Load curve for unloading Pull out Force see Figure 11 3 LFED Fed length see explanation below Remarks l Retractor IDs should start at 1 and be consecutive 25 The retractor node should not be on any belt elements The element defined should have one node
115. is recommended to avoid problems F 6 LS DYNA3D Version 936 Appendix F 3 The dummy passes through the airbag A most likely problem is that the contacts are improperly defined Another possibility is that the models were developed in an incompatible unit system The extra check for penetration flag if set to 1 on the contact control cards variable PENCHK in the CONTACT definitions may sometimes cause nodes to be prematurely released due to the softness of the penalties In this case the flag should be turned off 4 The OSP fails to converge This may occur when excessively large forces are passed to the OSP First check that unit systems are consistent and then look for improperly defined contacts in the LS DYNA3D input 5 Time step approaches zero This is almost always in the airbag If elastic or orthotropic MAT ELASTIC or MAT COMPOSITE material 1 or 22 is being used then switch to fabric material MAT FABRIC which is less time step size sensitive and use the fully integrated membrane element Increasing the damping in the control volume usually helps considerably Also check for cuts in the airbag where nodes are not merged These can allow elements to deform freely and cut the time step to zero LS DYNA3D Version 936 F 7 Appendix G APPENDIX G Interactive Graphics Commands Only the first four or less characterers of command are significant These commands are available in the interactive phase of L
116. length offset The area and offset are defined on either the cross section or element cards For a slack cable the offset should be input as a negative length For an initial tensile force the offset should be positive 19 182 MAT LS DYNA3D Version 936 MAT If a load curve is specified the Young s modulus will be ignored and the load curve will be used instead The points on the load curve are defined as engineering stress versus engineering strain i e the change in length over the initial length The unloading behavior follows the loading LS DYNA3D Version 936 19 183 MAT MAT MAT BILKHU DUBOIS FOAM This is Material Type 75 This model is for the simulation of isotropic crushable forms Uniaxial and triaxial test data have to be used For the elastic response the Poisson ratio is set to zero Card Format Card 1 1 2 3 4 5 6 7 8 me fete fet et ef VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density YM Young s modulus E LCPY Load curve ID giving pressure for plastic yielding versus volumetric strain see Figure 19 19 LCUYS Load curve ID giving unixial yield stress versus volumetric strain see Figure 19 19 Viscous damping coefficient 05 recommended value lt 50 The logarithmic volumetric strain is defined in terms of the relative volume V as y In V In defining the curves the stress and strain pairs should be positive values
117. loads are given in force per unit length s and t directions are defined on the ELEMENT BEAM keyword LS DYNA3D Version 936 18 3 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 LOAD BODY PARTS keyword If a part subset is defined then all nodal points belonging to the subset will have body forces applied The 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 Card Format for options X Y Z RX RY and RZ Default 18 4 LOAD LS DYNA3D Version 936 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 factor LCIDDR Load curve ID for dynamic relaxation phase optional This is only needed if dynamic relaxation is defined See CONTROL_DYNAMIC_RELAX ATION XC X center of rotation define for angular velocities Y center of rotation define for angular velocities 7 Z center of rotation define for angular velocities PSID Part set ID Remark 1 Angular
118. magnitude To model the rubber as an unconstrained material a hydrostatic work term is included in the strain energy functional which is function of the relative volume J Ogden 1984 way ea D 2 The asterisk indicates that the volumetric effects have be eliminated from the principal stretches E The number of terms n is may vary between to 8 inclusive and K is the bulk modulus Rate effects are taken into account through linear viscoelasticity by a convolution integral of the form LS DYNA3D Version 936 19 195 MAT MAT t b Sige t 2 8 d or in terms of the second Piola Kirchhoff stress S ij and Green s strain tensor Ej dt t Sij h t where gijj t 1 t t are the relaxation functions for the different stress measures This stress is addedto the stress tensor determined from the strain energy functional If we wish to include only simple rate effects the relaxation function is represented by six terms from the Prony series N g t 209 m 1 given by g Y Ge Pi i l This model is effectively a Maxwell fluid which consists of a dampers and springs in series We characterize this in the input by shear modulii G and decay constants B The viscoelastic behavior is optional and an arbitrary number of terms may be used The Mooney Rivlin rubber model model 27 is obtained by specifying n 1 In spite of the differences
119. matrix defined in terms of the material z L constants of the orthogonal material axes a b and c The inverse of C 15 defined as L 19 10 MAT LS DYNA3D Version 936 MAT o Ee dz D m a define a and d AOPT 0 0 AOPT 2 0 9 X 2 lt d is parallel to the z axis 1 shell element or middle surface of brick AOPT 1 0 V y a Included angle is b md specified in the element axis of x definition symmetry r x vxr z XXy r AOPT 4 0 Figure 19 1 Options for determining principal material axes a AOPT 0 0 b AOPT 1 0 c AOPT 2 0 Note that ax d and that b cxa 4 AOPT 3 0 and e AOPT 4 0 for brick elements LS DYNA3D Version 936 19 11 MAT MAT ab Up Vea 9 Note that E a 19 12 MAT LS DYNA3D Version 936 MAT MAT PLASTIC KINEMATIC This is Material Type 3 This model is suited to model isotropic and kinematic hardening plasticity with the option of including rate effects It is a very cost effective model and is available for beam Hughes Liu shell and solid elements Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic tangent hardening modulus see Figure 19 2 BETA Hardening paramet
120. 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 all velocities will be reset to zero 29 14 RESTART LS DYNA3D Version 936 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 Variable Type Default 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 LS DYNA3D Version 936 29 15 RESTART RESTART 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 29 16 RESTART LS DYNA3D Version 936 RESTART CONTROL DYNAMIC RELAXATION Purpose Define contro
121. of cycles between contact searching using three dimensional bucket searches Defaults recommended Flag for intermittent searching in old surface to surface contact using the interval specified as NSBCS above EQ 0 off EQ 1 on Contact surface maximum penetration check multiplier If the small penetration checking option PENCHK on the contact surface control card 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 and 15 See comments below EQ 0 logic is enabled default EQ 1 logic is skipped 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 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 su
122. on overall runtime is problem dependent but generally not very large Other methods are under consideration Default rsb expdir n This only applies when using Recursive Coordinate Bisection where 1 specifies the X coordinate direction 2 the Y and 3 the Z For a full explanation see the following item Default 1 expsf 1 This only applies when using Recursive Coordinate Bisection model will be compressed by a factor of t in the coordinate direction indicated by the keyword expdir before RCB is performed This in no way affects the geometry of the actual model but it has the effect of expanding the decomposition domains in the indicated direction by a factor of l t Preliminary experience indicates that this can be used to provide much improved load balance for contact problems For example if expdir is set to the punch travel direction for a sheet metal stamping problem and expsf is given as 0 each processor will be responsible for a whole column of the problem This result in the contact work being very equally distributed among the processors and in some such problems can result in dramatic speed improvements over the other decomposition methods Default 1 1 52 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION show If this Keyword appears in the decomposition section the D3PLOT file is doctored so that the decomposition can be viewed with the post processor Displaying material 1 will show that portion of th
123. 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 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 DYNA3D 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 e
124. properties must be defined for the tempertaure range that the material will see in the analysis Card Format 1 of 5 1 2 3 4 5 6 7 8 Card Format 2 of 5 Type Type LS DYNA3D Version 936 19 239 MAT MAT Card Format 4 of 5 Type Card Format 5 of 5 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be chosen TRO Thermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT LT 0 function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation T8 Temperatures T1 T8 8 Heat capacity at T1 T8 K8 Thermal conductivity at T1 T8 SOLT Solidus temperature TS must be TL LIQT Liquidus temperature must be gt TS LH Latent heat 19 240 MAT LS DYNA3D Version 936 MAT During phase change that is between the solidus and liquidus temperatures the heat capacity of the material will be enhanced to account for the latent heat as follows TAR L Ts c t 4i cos Ts T TT Where Tr liquidus termperature Ts solidus termperature T termperature m multiplier such that car Ts latent heat c hear capcity LS DYNA3D Version 936 19 241 MAT MAT MAT THERMAL ISOTROPIC
125. reference Failure is optional with two failure criteria available Optionally stiffness proportional damping can be defined In the stress initialization phase temperatures can be varied to impose the initial stresses This model is only available for shell elements 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 19 120 MAT LS DYNA3D Version 936 Card 4 Card 5 MAT VARIABLE MID RO EA EB EC PRBA PRCA PRCB GAB GBC GCA DT TRAMP ALPHA DESCRIPTION Material identification A unique number has to be chosen Mass density Ea Young s modulus in a direction Ep Young s modulus in b direction Ec Young s modulus in c direction Vba Poisson s ratio ba Poisson s ratio ca Veb Poisson s ratio cb Gap shear modulus ab Gbc shear modulus bc Gea shear modulus ca Temperature increment for isotropic stress initialization This option can be used during dynamic relaxation Time to ramp up to the final temperature Thermal expansion coefficient LS DYNA3D Version 936 19 121 MAT MAT VARIABLE LCIDA LCIDB EFAIL DTFAIL CDAMP AOPT XP YP ZP A1 A2 A3 D1 D2 D3 V1 V2 V3 19 122 MAT DESCRIPTION Optional load curve ID defining the nominal stress versus strain along a axis Strain is defined as Ag 1 where is the stretch ratio along the a axis Optional load curve ID defining th
126. s 2 where the deviatoric strain increment is defined as Ac ger 4AE Kj Now a check is made to see if the yield stress for the fully compacted material is exceeded by comparing trial _ 3 trial _trial Sef 580 sU 2 the effective trial stress to the defined yield stress SIGY If the effective trial stress exceeds the yield stress the stress components are simply scaled back to the yield surface 511 9 y trial U trial Seff Now the pressure is updated using the elastic bulk modulus K ES poct 3 1 2v to obtain the final value for the Cauchy stress QU y y After completing the stress update transform the stresses back to the global configuration LS DYNA3D Version 936 19 83 MAT MAT unloading and reloading path Volumetric strain 1 V curve extends into negative unloading is based on volumetric strain quadrant since the interpolated Young s LS DYNA3D will extrapolate using modulii which must the two end points It is important provide an unloading that the extropolation does not extend tangent that exceeds the into the negative stress region loading tangent Figure 19 7 Stress quantity versus volumetric strain Note that the yield stress at a volumetric strain of zero is non zero In the load curve definition see DEFINE CURVE the time value is the volumetric strain and the function value is the yield stre
127. same function and may also be used Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Shell node ID NSID Solid nodal set ID see SET NODE OPTION The shell brick interface an extension of the tied surface capability ties regions of hexahedron elements to regions of shell elements A shell node may be tied to up to nine brick nodes lying along the tangent vector to the nodal fiber See Figure 4 10 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 LS DYNA3D Version 936 4 37 CONSTRAINED CONSTRAINED Nodes are constrained to stay on fiber vector Nodes 51 3 coincident Figure 4 10 The interface between shell elements and solids ties shell node 51 to a line of nodes on the solid elements n1 n5 It is very important for the nodes to be aligned 4 38 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED SPOTWELD Purpose Define massless spotwelds between non contiguous nodal pairs The nodes must not have the same coordinates A rigid beam is assumed between the nodal pairs thus nodal rotations and dis
128. shells Merging of occupants airbags and belts with car models 1 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 40 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION TAURUS POST PROCESSING LS TAURUS Brown and Hallquist 1984 processes output from LS DYNA3D LS TAURUS reads the binary plot files generated by LS DYNA3D 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 TAURUS can compute a variety of strain measures reaction forces along constrained boundaries and momenta LS TAURUS is operational on the CRAY VAX SUN APOLLO IBM RS6000 SGI STARDENT HP and MIPS computers Interfaces from LS TAURUS to other commercial post processors are available LS DYNA3D generates three binary databases One contains information for complete states at infrequent intervals 50 to 100 states of this sort is typical in a LS DYNAS3D 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 print
129. should be defined These nine curves define the time history of the displacement gradient components shown in Table H 1 The velocity gradient matrix L is approximated by taking the time derivative of the ij components in Table H 1 If these components are considered to form a tensor 5i then io Od and the strain rate tensor is defined as t Lj Lij y 2 and the spin tensor as Eos 0 so y J U 2 LS DYNA3D Version 936 H 1 Appendix H Table H 1 Load Curve Definitions versus Time Load Curve Number Component Definition ox 2 LS DYNA3D Version 936 Appendix H INTERACTIVE DRIVER COMMANDS After reading the input file and completing the calculations LS DYNA3D gives a command prompt to the terminal A summary of the available interactive commands is given below An on line help package is available by typing HELP ACCL Scale all abscissa data by f Default is f 1 ASET amin omax Set min and max values on abscissa to amin and amax respectively If amin amax 0 scaling is automatic CHGL n Change label for component n LS DYNA3D prompts for new label CONTINUE Re analyze material model CROSS c2 Plot component c versus c2 ECOMP Display component numbers on the graphics display x stress 2 y stress 3 z stress 4 xy stress 5 yz stress 6 zx stress 7 effective plastic strain 8 pressure 9 von Mises effective stress 10 Ist principal deviatoric stress 11 2nd principal d
130. 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 DYNA3D Version 936 16 3 INTEGRATION INTEGRATION w flange width tr flange thickness d depth tw web thickness Sref location of reference surface normal to s Hughes Liu beam only tref location of reference surface normal to t Hughes Liu beam only Type 1 W section Type 2 C section t 4 b 5 5 4 H w Type 3 Angle section Type 4 T section ps MEE HE Figure 16 3a Standard beam cross sections 16 4 INTEGRATION LS DYNA3D Version 936 INTEGRATION Type 5 Rectangular tubin t Type 7 Trapezoidal section t Figure 16 3b Standard beam cross sections LS DYNA3D Version 936 16 5 INTEGRATION INTEGRATION INTEGRATION SHELL Purpose Define user defined through the thickness integration rules for the shell element Card Format Card 1 1 2 3 4 5 6 7 8 Define NIP cards below 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 EQ 0 integration points are defined below EQ 1 integration points are equally spaced through thickness such that the shell is subdivided into N
131. starting with a volumetric strain value of zero 19 184 MAT LS DYNA3D Version 936 MAT gt 2 Uniaxial yield stress Pressure yield NNR DAN VOLUMETRIC STRAIN Figure 19 19 Behavior of crushable foam Unloading is elastic The yield surface is defined as an ellipse in the equivalent pressure and von Mises stress plane LS DYNA3D Version 936 19 185 MAT MAT MAT GENERAL VISCOELASTIC This is Material Type 76 This material model provides a general viscoelastic Maxell model having up to 6 terms in the prony series expansion and is useful for modeling dense continuum rubbers and solid explosives Either the coefficients of the prony series expansion or a relaxation curve may be specified to define the viscoelastic deviatoric and bulk behavior Card Format Card 1 1 2 3 4 5 6 7 8 Variable Insert a blank card here if constants are defined on cards 3 4 below Card 2 1 2 3 4 5 6 7 8 LCID BSTART TRAMP LCIDK BSTARTK TRAMPK Card Format for viscoelastic constants Up to 6 cards may be input A keyword card with a in column 1 terminates this input if less than 6 cards are used These cards are not needed if relaxation data is defined The number of terms for the shear behavior may differ from that for the bulk behavior simply insert zero if a term is not included Optional 1 2 3 4 5 6 7 8 Cards 19 186 MAT LS DYNA3D Version 936 VARIABLE MID RO BULK LCID NT
132. strain rate becomes 4 da f Tp a 19 18 LS DYNA3D Version 936 MAT MAT SOIL AND FOAM This is Material Type 5 This is a very simple model and works in some ways like a fluid It should be used only in situations when soils and foams are confined within a structure or when geometric boundaries are present Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 EPS7 EPS8 Card 4 LS DYNA3D Version 936 19 19 MAT MAT Card 5 Variable Type Card 6 Variable Type VARIABLE MID RO G K AO Al A2 PC P1 P2 PN 19 20 MAT DESCRIPTION Material identification A unique number has to be chosen Mass density Shear modulus Bulk modulus for unloading used for VCR 0 0 Yield function constant for plastic yield function below Yield function constant for plastic yield function below Yield function constant for plastic yield function below Pressure cutoff for tensile fracture Volumetric crushing option EQ 0 0 on EQ 1 0 loading and unloading paths are the same Volumetric strain values natural logarithmic values see comments below A maximum of 10 values are allowed and a minimum of 2 values are necessary The tabulated values must competely cover the expected values in the analysis If the first value is not for a volumetric strain value of zero then the point 0 0 0 0 will be automatically generated and upto a further nine add
133. stress plastic shear strain curve at low levels of shear stress The function F is defined as u o o eo mafo sore where N is a constant defining the size of the yield surface The value of N may be interpreted as the radial distant between the outside of the initial yield surface and the inside of the limit surface In order for the limit surface of the kinematic hardening cap model to correspond with the failure 19 76 MAT LS DYNA3D Version 936 MAT envelope surface of the standard cap model the scalar parameter must be replaced N in the definition Fe The cap model contains a number of parameters which must be chosen to represent a particular material and are generally based on experimental data The parameters and y are usually evaluated by fitting a curve through failure data taken from a set of triaxial compression tests The parameters W D and define the cap hardening law The value W represent the void fraction of the uncompressed sample and D governs the slope of the initial loading curve in hydrostatic compression The value of R is the ration of major to minor axes of the quarter ellipse defining the cap surface Additional details and guidelines for fitting the cap model to experimental data are found in Chen and Baladi 1985 LS DYNA3D Version 936 19 77 MAT MAT MAT HONEYCOMB This is Material Type 26 The major use of this material model is for honeycomb and foam materials
134. t axis Load curve ID yield force versus plastic displacement r axis Load curve ID yield force versus plastic displacement s axis Load curve ID yield force versus plastic displacement t axis Load curve ID yield moment versus plastic rotation r axis Load curve ID yield moment versus plastic rotation s axis Load curve ID yield moment versus plastic rotation t axis Optional failure parameter If zero the corresponding force is not considered in the failure calculation Optional failure parameter If zero the corresponding force F is not considered in the failure calculation Optional failure parameter If zero the corresponding force is not considered in the failure calculation Optional failure parameter If zero the corresponding moment My is not considered in the failure calculation Optional failure parameter If zero the corresponding moment Ms is not considered in the failure calculation Optional failure parameter If zero the corresponding moment Mi is not considered in the failure calculation Optional failure parameter If zero the corresponding displacement is not considered in the failure calculation Optional failure parameter If zero the corresponding displacement us is not considered in the failure calculation Optional failure parameter If zero the corresponding displacement ut is not considered in the failure calculation Optional failure parameter If zero the correspond
135. tail of any outward drawn normal vector n originating on wall tail and terminating in space head see Figure 22 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 Interface friction EQ 0 0 frictionless sliding after contact EQ 1 0 stick condition after contact 0 lt FRIC lt 1 Coulomb friction coefficient x coordinate of head of edge vector 1 see Figure 22 1 y coordinate of head of edge vector 1 z coordinate of head of edge vector Length of ledge A zero valure defines an infinite size plane Length of m edge A zero valure defines an infinite size plane Length of prism in the direction negative to n see Figure 22 1 Radius of cylinder Length of cylinder see Figure 22 1 Only if a valure larger than zero is specified is a finite length assumed Radius of sphere Stonewall motion curve number see DEFINE CURVE Type of motion EQ 0 velocity specified EQ 1 displacement specified 22 5 RIGIDWALL RIGIDWALL VARIABLE DESCRIPTION VX x direction cosine of velocity displacement vector VY y direction cosine of velocity displacement vector VZ z direction cosine of velocity displacement vector 22 6 RIGIDWALL LS DYNA3D Version 936 RIGIDWALL Figure 22 1 Vector n determines the orientation of the generalized stonewalls For the prescribed motion op
136. that the distance between the two nodes is kept constant throughout any motion No failure can be specified Card Format Variable Type Default VARIABLE DESCRIPTION NI Node ID N2 Node ID Remark l Nodes connected by a rivet cannot be members of another constraint set that constrain the same degrees of freedom a tied interface or a rigid body 1 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 DYNA3D Version 936 4 35 CONSTRAINED CONSTRAINED CONSTRAINED SHELL IN SOLID Purpose Couple a Lagrangian mesh of shells to the material points of an Eulerian flow 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 Card Format Default VARIABLE DESCRIPTION PSIDS Part or part set ID of embedded shells see PART or PART PSIDM Part or part set ID of solid elements see PART or SET PART SSTYP Slave type EQ 0 part set ID EQ 1 part ID MSTYP Master type EQ 0 part set ID EQ 1 part ID 4 36 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED SHELL TO SOLID Purpose Define a tie between a shell edge and solid elements Nodal rigid bodies can perform the
137. 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 12 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 From this data and the maximum excess compression the material has attained Umax the pressure for any excess compression u can be determined 12 26 EOS LS DYNA3D Version 936 EOS 1 0 Virgin loading curve Completely crushed curve Partially crushed curve ML M 0 04 08 12 16 u 20 2 Excess Compression Figure 12 2 Pressure versus compaction curve Unloading occurs along the virgin loading curve until the excess compression surpasses uj 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 p then all unloading will follow the completely crushed curve For unloading between u1 and a partially crushed curve is determined by the relationship
138. 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 Quadrature 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 1 14 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION INTERFACE 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 LINKING SEGMENT as master segments and in 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
139. the isotropic Young s modulus and Poisson s ratio respectively The input for the fiber directions and liner should be input as zero for the isotropic elastic fabric Young s modulus transverse direction set to zero for isotropic elastic material Young s modulus normal direction set to zero for isotropic elastic material Poisson s ratio ba direction Poisson s ratio ca direction set to zero for isotropic elastic material Vcb Poisson s ratio cb direction set to zero for isotropic elastic material Gap shear modulus ab direction set to zero for isotropic elastic material Gbc shear modulus bc direction set to zero for isotropic elastic material shear modulus ca direction set to zero for isotropic elastic material LS DYNA3D Version 936 19 105 MAT MAT VARIABLE CSE EL PRL LRATIO DAMP AOPT XP YP ZP Al A2 A3 V1 V2 V3 D1 D2 D3 19 106 MAT DESCRIPTION Compressive stress elimination option default 0 0 EQ 0 0 don t eliminate compressive stresses EQ 1 0 eliminate compressive stresses Young s modulus for elastic liner optional Poisson s ratio for elastic liner optional Ratio of liner thickness to total fabric thickness Rayleigh damping coefficient A 0 05 coefficient is recommended corresponding to 5 of critical damping Sometimes larger values are necessary Material axes option EQ 0 0 locally orthotropic with material axes determined
140. the least squares fit Exit option EQ 0 0 stop if strain limits are exceeded recommended NE 0 0 continue if strain limits are exceeded The curve is then extrapolated Maximum strain limit Green St Venant Strain Minimum strain limit Green St Venant Strain Specimen gauge length see Figure 19 8 Specimen width see Figure 19 8 Specimen thickness see Figure 19 8 Load curve ID see DEFINE CURVE giving the force versus actual change in gauge length See also Figure 19 9 for an alternative definition The constants can be defined directly or a least squares fit can be performed if the uniaxial data SGL SW ST and LCID is available If a least squares fit is chosen then the terms to be included in the energy functional are flagged by setting their corresponding coefficients to unity If all coefficients are zero the default is to use only the terms involving I I gt defaults to unity if the least square fit is used The strain energy functional U is defined in terms of the input constants as LS DYNA3D Version 936 2 3 4 U t C299 t C300 400 C110 1 2 2 2 C210 112 C91012 Copol 5 f J 19 97 MAT MAT where the invariants can be expressed in terms of the deformation gradient matrix Fj and the Green St Venant strain tensor Ejj h Ej 1 a 2 5j Spa Epi Ej The derivative of U with respect to a component of strain give
141. 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 3 Before After Figure 11 4 Elements passing through slipring 11 22 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SHELL OPTION Available options include BLANK THICKNESS BETA Purpose Define three and four node shell or membrane element The type of the element is specified through the part ID see PART and the section ID see SECTION SHELL Also the thickness of each element can be specified For orthotropic and anisotropic materials a local material axis can be defined Card Format Card 1 1 2 3 4 5 6 7 8 9 10 Variable pe idi in LS DYNA3D Version 936 11 23 ELEMENT ELEMENT Optional Card Requir
142. 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 dollar sign in column one precedes a comment and causes the input line to be ignored Data blocks are not a requirement for LS DYNA3D 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 DYNA3D 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 N2 N3 N4 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 ide
143. truss elements rivets based on equations of rigid body dynamics e massless beam elements spot welds based on equations of rigid body dynamics e expanded databases with more history variables and integration points force limited resultant beam e rotational spring and dampers local coordinate systems for discrete elements e resultant plasticity for C triangular element e energy dissipation calculations for stonewalls e hourglass energy calculations for solid and shell elements e viscous and Coulomb friction with arbitrary variation over surface e distributed loads on beam elements Cowper and Symonds strain rate model e segmented stonewalls e stonewall Coulomb friction e stonewall energy dissipation e airbags 1990 e nodal rigid bodies e automatic sorting of triangular shells into C groups mass scaling for quasi static analyses user defined subroutines warpage checks on shell elements e thickness consideration in all contact types e automatic orientation of contact segments e sliding interface energy dissipation calculations e nodal force and energy database for applied boundary conditions e defined stonewall velocity with input energy calculations LS DYNA3D Version 936 L5 INTRODUCTION INTRODUCTION and in 1991 1992 rigid deformable material switching rigid bodies impacting rigid walls strain rate effects in metallic honeycomb model 26 shells and beams inte
144. usual way i e Q t AtQ and the hourglass resultant forces are then H M fal 10 Mey 90 H W fai 710 where the superscript H emphasizes that these are internal force contributions from the hourglass deformations 13 4 HOURGLASS LS DYNA3D Version 936 INCLUDE INCLUDE INCLUDE Purpose File to be included in this keyword file The file contents are placed directly at the location of the INCLUDE line Card Format Card 1 1 VARIABLE DESCRIPTION FILENAME File name of file to be included in this keyword file 80 characters maximum 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 dummy k INCLUDE bag k CONTACT eee END Note that the command END terminates the include file LS DYNA3D Version 936 14 1 INCLUDE INCLUDE 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
145. velocity is assumed to have the units of radians per unit time about a global axis LS DYNA3D Version 936 18 5 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 Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION N1 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 18 6 LOAD LS DYNA3D Version 936 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 factor 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 Remark 1 Required for angular velocity loading LS DYNA3D Version 936 18 7 LOAD LOAD LOAD BRODE Purpose Define Brode function for application of pressure loads due to explosion see Brode 1970 also see ALOAD SEGMENT LOAD SEGMENT SET or LOAD SHELL Car
146. versus time EQ 0 use constant multiplier value HMULT LT 0 function versus temperature HMULT Curve multiplier for h TLCID Load curve ID for Too versus time see DEFINE CURVE EQ 0 use constant multiplier value TMULT TMULT Curve multiplier for Too A convection boundary condition is calculated using 4 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 DYNA3D Version 936 3 3 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 boundarys 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 Format Default 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
147. where Co and p are the inflator orifice coefficient area and gas density respectively Further additional 2 cards are required for JETTING models The following additional cards are defined for the WANG NEFSKE JETTING and 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 Default 1 12 AIRBAG LS DYNA3D Version 936 AIRBAG 1st additional card of 2 required for NEFSKE MULTIPLE JETTING option Card 1 1 2 3 4 5 6 7 8 XJFP YJFP XJVH YJVH ZJVH LCJRV BETA Default Remark 2nd additional card of 2 required for WANG NEFSKE JETTING WANG NEFSKE MULTIPLE JETTING option Card 2 1 2 3 4 5 6 7 8 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
148. where pe is the external pressure and po is the internal pressure in the bag A critical pressure relationship is defined as 2 med where y is the ratio of specific heats If Q7Qerit Q Wang and Nefske define the mass flow through the vents and leakage by TOPE Dy Y yR Ls CA Y Dg I1 f C53 23 0 41 0 2 R n C53403 m o be 1 i o 2 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 Pc 2 y 1 Qcrit A i LS DYNA3D Version 936 1 11 AIRBAG AIRBAG where p is a critical pressure at which sonic flow occurs is the inflator pressure The exhaust pressure is given by Pe Pa Pe Pc if lt where p is the pressure in the control volume The mass flow into the control volume is governed by the equation 2 yyh 8 Q 7 Min CoAo42prpr yal
149. will be created if necessary This is of primary use on systems where each processor has its own local disk Default global path e Decomposition Holds decomposition specific options file filename The name of the file that holds the decomposition information This file will be created if the pre decomposition program is being run Otherwise it is expected to exist in the current working directory If the filename does not end with the extension pre then this extension is added If this option is not specified there is no default value numproc For pre decomposition only The problem will be decomposed for n processors The resulting decomposition file can later be used on any number of processors that evenly divides n LS DYNA3D Version 936 L51 INTRODUCTION INTRODUCTION costinc n The elements involved in contact are considered to be this much more computationally expensive during decomposition The average thin shell is given a weight of about 30 so setting costinc to 30 would indicate that each shell element involved in contact is about twice as computationally expensive as a normal shell element Default 0 method name Currently there are three decomposition methods supported Method rsb is Recursive Spectral Bisection This method is only available when using the pre decomposition program Method greedy is a much faster but less sophisticated method Method rcb is Recursive Coordinate Bisection The impact
150. 0 set to 1000 machine roundoff DCP Divergence control parameter steady state problems 0 3 DCP 1 0 default 1 0 transient problems 0 0 lt DCP 1 0 default 0 5 6 26 CONTROL LS DYNA3D Version 936 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 Variable ATYPE PTYPE SOLVER CGTOL GPT ES NE NN Default VARIABLE DESCRIPTION ATYPE Thermal analysis type EQ 0 Steady state analysis EQ 1 transient analysis PTYPE Thermal problem type see CONTROL THERMAL NONLINEAR if no zero EQ 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 dseg diagonal scaled conjugate gradient iterative default EQ 4 incomplete choleski conjugate gradient iterative CGTOL Convergence tolerance for iterative solver types 3 and 4 EQ 0 0 setto 1 0e 04 GPT Number of Gauss points to be used in the solid elements EQ 0 the default is set to 8 EQ 1 one point quadrature is used LS DYNA3D Version 936 6 27 CONTROL CONTROL Remark 1 Use of a direct solver SOLVER e g 1 or 2 is mostly less e
151. 19 107 MAT MAT MAT PLASTIC GREEN NAGHDI RATE This is Material Type 35 This model is available only for brick elements and is similar to model 3 but uses the Green Naghdi Rate formulation rather than the Jaumann rate for the stress update For some cases this might be helpful This model also has a strain rate dependency following the Cowper Symonds model Card Format Card 1 1 2 3 4 5 6 7 8 Type Card 2 VARIABLE DESCRIPTION MID Material identification RO Density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic hardening modulus SRC Strain rate parameter C SRP Strain rate parameter P BETA Hardening parameter 0 lt B lt 1 19 108 MAT LS DYNA3D Version 936 MAT MAT 3 PARAMETER BARLAT This is Material Type 36 This model was developed by Barlat and Lian 1989 for modelling sheets with anisotropic materials under plane stress conditions This material allows the use of the Lankford parameters for the definition of the anisotropy This particular development is due to Barlat and Lian 1989 Card Format Card 1 1 2 3 4 5 6 7 8 Type Card 2 Type Card 3 Type Card 4 Variable LS DYNA3D Version 936 19 109 MAT MAT Card 5 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus E PR Poisson s ratio V HR Hardening rule EQ 1 0 linear default EQ 2 0 exponential M
152. 1990 The unreacted propellant and the reaction product equations of state are both of the form 9C T p Ag EU pe V d LS DYNA3D Version 936 12 23 EOS EOS 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 T is temperature in d is the co volume and and R2 are constants Setting A B 0 yields the van der WaalOs co volume equation of state The JWL equation of state is generally useful at pressures above several kilobars while the van der WaalOs 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 Ocold compression and internal energies are used the calculated temperatures are very reasonable and thus can be used to check propellant performance The reaction rate used for the propellant deflagration process is of the form T 7 1 F p V 1 Frp t i m for 0 F lt for Fio lt F 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 Flimit and are constants used to describe the pressure dependance and surface area dependence of the reaction rates Two or more pressure dependant reaction rates ar
153. 3D The CONTACT 1D is for modeling rebars in concrete structure 1 12 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION CONTROL Options available in the CONTROL section allow the resetting of default global parameters such as the hourglass type the contact penalty scale 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 DYNA3D With this keyword the frequency of writing the various databases can be determined DEFINE This section allows the user to define curves for loadings 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 deforma
154. 4 EOS LS DYNA3D Version 936 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 E0 Initial internal energy vo Initial relative volume The Sack equation of state defines pressure as A _ B B ud v 3 Be y V V and is used for detonation products of high explosives LS DYNA3D Version 936 12 5 EOS EOS EOS GRUNEISEN This is Equation of state Form 4 Card Format Variable EOSID Type Card 2 Variable Type VARIABLE DESCRIPTION EOSID Equation of state ID C 51 52 53 E0 Initial internal energy vo Initial relative volume 12 6 EOS LS DYNA3D Version 936 EOS The Gruneisen equation of state with cubic shock velocity particle velocity defines pressure for compressed materials as Po c 1 79 aS u 2 p 7 Yo ap E u 1 S 1 u 55 S4 51 u 2 ud and for expanded materials as 2 It Yo where C is the intercept of the vs vp curve S1 S2 and 53 are the coefficients of the slope of the vs B Vp curve yo is the Gruneisen gamma is the first order volume correction to yo and u Po LS DYNA3D Version 936 12 7 EOS EOS EOS RATIO OF POLYNOMIALS This is Equation of state Form 5 Card Format 110 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
155. 4 cards follow MAT ANISOTROPIC ELASTIC 5 cards follow Card Format of Cards 1 and 2 for the ORTHO option Card 1 1 2 3 4 5 6 7 8 Card 2 Type LS DYNA3D Version 936 19 7 MAT MAT Card Format of Cards 1 2 and 3 for the ANISO option Card 1 1 2 3 4 5 6 7 8 2 3 Card Format of Cards 3 4 and 4 5 for the ORTHO ANISO options Card 3 4 Card 4 5 19 8 LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density Define for the ORTHO option only EA Young s modulus in a direction EB Ep Young s modulus in b direction EC Ec Young s modulus in c direction PRBA Vba Poisson s ratio ba PRCA Poisson s ratio ca PRCB Veb Poisson s ratio cb GAB Gap shear modulus ab GBC Gbc shear modulus bc GCA Gea shear modulus ca Due to symmetry define the upper triangular Cij s for the ANISO option only C11 The 1 1 term in the 6 6 anisotropic constitutive matrix Note that 1 corresponds to the a material direction C12 The 1 2 term in the 6 6 anisotropic constitutive matrix Note that 2 corresponds to the b material direction C66 The 6 6 term in the 6 6 anisotropic constitutive matrix Define for both options AOPT Material axes option see Figure 19 1 LS DYNA3D Version 936 19 9 MAT MAT VARIABLE DESCRIPTION EQ 0 0 locally orthotropic wi
156. 7 8 Card 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic hardening modulus see notes for model 37 R Anisotropic hardening parameter see notes for model 37 19 118 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION HLCID Load curve ID defining effective stress versus effective plastic strain The yield stress and hardening modulus are ignored with this option LCIDFLD Load curve ID defining the Flow Limit Diagram Minor strains in percent are defined as abcissa values and Major strains in percent are defined as ordinate values The flow limit diagram is shown in Figure 19 11 In defining the curve list pairs of minor and major strains starting with the left most point and ending with the right most point see DEFINE CURVE See material model 37 for the theoretical basis The first history variable is the maximum strain ratio defined by E major workpiece major r Emnr 0 PLANESTRAIN 6 corresponding to minor workpiece 95 MAJOR STRAIN 10 20 30 50 MINOR STRAIN Figure 19 11 Flow limit diagram LS DYNA3D Version 936 19 119 MAT MAT MAT NONLINEAR ORTHOTROPIC This is Material Type 40 This model allows the definition of an orthotropic nonlinear elastic material based on a finite strain formulation with the initial geometry as the
157. 748 140 4 0 17 920 135 3 9 9 450 125 4 0 30 030 237 3 9 111 070 211 3 8 74 810 163 33 HP 128 735 Mod99 186 35 1 0 4 657 35 1 0 2 338 31 1 0 7 734 61 1 0 29 250 55 1 0 21 005 46 1 0
158. 88 1989 JOHN O HALLQUIST LSTC C ALL RIGHTS RESERVED Qe e e e hee e e e e Se he e he e e k e k se k k he k e k se k k he k e k k k k k k e k k k k ke k e k k k k ke k k k k k c CHARACTER MESSAG INTEGER CYCLE USER SUBROUTINE FOR SOLUTION CONTROL NOTE LS DYNA3D USED AN INTERNAL NUMBERING SYSTEM ACCOMODATE ARBITRARY NODE NUMBERING TO ACCESS INFORMATION FOR USER NODE N ADDRESS ARRAY LOCATION M M L F N 1 TO OBTAIN USER NODE NUMBER N CORRESPONDING TO ARRAY ADDRESS M SET N L FINV M 1 ARGUMENTS NUMNP NUMBER OF NODAL POINTS NDOF NUMBER OF DEGREES IF FREEDOM PER NODE TIME CURRENT SOLUTION TIME PRTC OUTPUT INTERVAL FOR TAURUS TIME HISTORY DATA PLTC OUTPUT INTERVAL FOR TAURUS STATE DATA FRCI OUTPUT INTERVAL FOR TAURUS INTERFACE FORCE DATA PRTO OUTPUT TIME FOR TIME HISTORY FILE PLTO OUTPUT TIME FOR STATE DATA FRCO OUTPUT TIME FOR FORCE DATA VT 3 NUMNP NODAL TRANSLATIONAL VELOCITY VECTOR VR 3 NUMNP NODAL ROTATIONAL VELOCITY VECTOR THIS ARRAY IS DEFINED IF AND ONLY IF NDOF 6 AT 3 NUMNP NODAL TRANSLATIONAL ACCELERATION VECTOR AR 3 NUMNP NODAL ROTATIONAL ACCELERATION VECTOR THIS ARRAY IS DEFINED IF AND ONLY IF NDOF 6 UT 3 NUMNP NODAL TRANSLATIONAL DISPLACEMENT VECTOR UR 3 NUMNP NODAL ROTATIONAL DISPLACEMENT VECTOR THIS ARRAY IS DEFINED IF AND ONLY IF NDOF 6 XMST NUMNP RECIPROCAL OF NODAL TRANSLATIONAL MASSES XMSR NUMNP RECIPROCAL OF NODAL ROTATIONAL MASSES THIS ARRAY IS DEFINED IF AND ONL
159. 9 20 DAMPING GLOBAL 3 deret penale 29 21 DATABASE OPTION ies SUBIRE 29 22 DATABASE BINARY OPTION rtt 29 24 DBEEETIE OPTION eee eee ee te a eate et ut ue baee ote 29 25 INTERPACE SPRINGBAQCK S ig tpe fe ede ec ee ere feries 29 27 RIGID DEFORMABLE OPTION 2 2222020040000000 29 29 5 55 2220 2222200 200 000 0 0 29 32 S TRESS INFEDAELZAT ION ie petet cete eo orte eee neret eret etre t tp ete ote 29 33 LS DYNA3D Version 936 TABLE OF CONTENTS STRESS INITIALIZATION DISCRETE eese 29 34 STRESS INITIALIZATION 2 2 2 0 29 34 TERMINATION OPTION repe 29 35 29 37 no 30 1 APPENDIX A USER DEFINED MATERIALS reir Oe APPENDIX USER DEFINED AIRBAG SENSOR B 1 APPENDIX C USER DEFINED SOLUTION 1 APPENDIX D USER DEFINED INTERFACE rennen nnne nnne enne D 1 APPENDIX E USER DEFINED INTERFACE FRICTION E 1 APPENDIX F OCCUPANT SIMULATION INCLUDING THE COUPLING
160. 936 MAT MAT DAMPER NONLINEAR VISCOUS This material allows to simulate a nonlinear versus translation or rotational damper with arbitrary force velocity resp moment rotational velocity dependency With the damper located between two nodes only one degree of freedom is connected Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen LCDR Load curve identification describing force versus rate of displacement relationship resp moment versus rate of rotation relationship LS DYNA3D Version 936 19 221 MAT MAT MAT SPRING GENERAL NONLINEAR This material allows to simulate a general nonlinear translational or rotational spring with arbitrary loading and unloading definitions Optionally hardening or softening can be defined With the spring located between two nodes only one degree of freedom is connected Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen LCDL Load curve identification describing force versus displacement resp moment versus rotation relationship for loading see Figure 19 25 LCDU Load curve identification describing force versus displacement resp moment versus rotation relationship for unloading see Figure 19 25 BETA Hardening parameter p EQ 0 0 tensile and compressive yield with strain softening negative or zero slope allowed in the
161. 936 11 9 ELEMENT ELEMENT VARIABLE DESCRIPTION SBSIDI 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 z 1 Remarks 1 Pretensioner ID s should start at 1 and be consecutive 2 At least 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 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
162. 9e 9 l For further explanation see PART and SECTION SHELL 3 Current NASTRAN only supports shell element with constant thickness T 27 6 TRANSLATE LS DYNA3D Version 936 TRANSLATE For further explanation see PART and SECTION SOLID PSOLID PID MID SCID EOSID HGID 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 DYNA3D will treat it as nodal rigid body constraint Otherwise LS DYNA3D will use nodal constraints to treat this RBE2 LS DYNA3D Version 936 27 7 TRANSLATE USER USER USER INTERFACE OPTION 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 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 Default LS DYNA3D Version 936 28 1 USER USER Card Format Use as many cards as necessary to define NOCI variables 1 2 3 4 5 6 7 8
163. ACE TYPE ID PENCHK ELEMENT FORMULA FOR RELEASE OF TYPE PENETRATING NODAL POINT 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 d XPENE thickness of shell element a3 a5 a10 d 0 5 thickness of solid element d 0 4 slave thickness master thickness d 0 5 thickness of solid element d 0 4 slave thickness master thickness Table 5 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 5 18 CONTACT LS DYNA3D Version 936 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 stiffne
164. AMPER NONLINEAR VISCOUS MAT SPRING GENERAL NONLINEAR SPRING MAXWELL MAT SPRING INELASTIC For the seatbelts one material is available MAT_SEATBELT For thermal materials in a coupled structural thermal or thermal only analysis six materials are available These materials are related to the structural material via the PART card Thermal materials are defined only for solid and shell elements MAT THERMAL ISOTROPIC MAT THERMAL ORTHOTROPIC MAT THERMAL ISOTROPIC TD MAT THERMAL ORTHOTROPIC TD MAT THERMAL ISOTROPIC PHASE CHANGE MAT THERMAL ISOTROPIC TD LC LS DYNA3D Version 936 19 3 MAT MAT MAT ELASTIC OPTION This is Material Type 1 This is an isotropic elastic material and is available for beam shell and solid elements in LS DYNA3D A specialization of this material allows the modeling of fluids Options include BLANK FLUID such that the keyword cards appear MAT ELASTIC MAT ELASTIC FLUID The fluid option is valid for solid elements only Define the following card for all options Card Format Variable Default 19 4 MAT LS DYNA3D Version 936 MAT Define the following extra card for the FLUID option Card Format Variable VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio DA Axial damping factor used for Belytschko Schwer beam type 1 only DB Bending da
165. ANSVERSELY ANISOTROPIC seen 19 119 MAT NONLINEAR 2 4 01 0 4 00000000 nennen nennen 19 121 MAT USER DEFINED MATERIAL MODELS emen 19 125 ii niit tte tee pee ge tecto erbe 19 128 MAT BAMMAN 2 22022202 0 0 000000 19 134 CLOSED CELL 50 19 137 MAT ENHANCED COMPOSITE 0 2 19 140 MAT LOW DENSITY FOAM Pese aero E 19 145 MAT COMPOSITE FAILURE MODEL 1 19 149 EEASTIC WITH VISCOSITY citer tte ete rate te pre 19 153 MAT KELVIN MAXWELL VISCOELASTIC eene 19 157 MAT VISCOUS FOAM e E Hee RETE ERR EYE ERE 19 159 MAT CRUSHABLEE FOAM tete ee e ee ee DU eine et ete et teg 19 161 MAT RATE SENSITIVE POWERLAW PLASTICITY 2 22 2 1 19 163 MAT MODIFIED ZERILLI ARMSTRONG eene nennen heiter 19 165 MAT LINEAR ELASTIC DISCRETE BEAM eene 19 168 MAT NONLINEAR ELASTIC DISCRETE BEAM Ie 19 170 MAT NONLINEAR PLASTIC DISCRETE BEAM eere 19 172 MAT SID DAMPER DISCRETE BEAM erem Ime 19 177 MAT HYDRAULIC GAS DAMPER DISCRETE BEAM
166. AT_BAMMAN 10 2 3 TYPE 52 MAT BAMMAN DAMAGE 0 2 3 53 CLOSED CELL FOAM 0 TYPE 54 ENHANCED COMPOSITE DAMAGE 2 57 LOW DENSITY 0 59 COMPOSITE FAILURE MODEL 0 2 TYPE 60 ELASTIC WITH VISCOSITY 0 2 TYPE 61 MAT KELVIN MAXWELL VISCOELASTIC 0 62 VISCOUS FOAM 0 TYPE 63 CRUSHABLE FOAM 0 TYPE 64 RATE SENSITIVE POWERLAW PLASTICITY 0 2 3 TYPE 65 MODIFIED ZERILLI ARMSTRONG 0 TYPE 66 MAT LINEAR ELASTIC DISCRETE BEAM 1D TYPE 67 NONLINEAR ELASTIC DISCRETE BEAM 1D TYPE 68 NONLINEAR PLASTIC DISCRETE BEAM 1D 69 SID DAMPER DISCRETE BEAM 1D 19 2 MAT LS DYNA3D Version 936 MAT TYPE 70 HYDRAULIC GAS DAMPER DISCRETE BEAM 1D TYPE 71 MAT CABLE DISCRETE BEAM 1D 75 BILKHU DUBOIS FOAM 0 TYPE 76 GENERAL VISCOELASTIC 0 77 8 RUBBER 0 and OGDEN RUBBER 0 TYPE 78 MAT SOIL CONCRETE 0 TYPE 79 MAT HYSTERETIC SOIL 0 81 MAT PLASTICITY WITH DAMAGE 2 TYPE 86 MAT_ORTHOTROPIC_VISCOELASTIC 2 87 CELLULAR RUBBER 0 90 MAT ACOUSTIC 0 For the discrete springs and dampers eight materials are available SPRING ELASTIC MAT DAMPER VISCOUS SPRING ELASTOPLASTIC SPRING NONLINEAR ELASTIC MAT D
167. AT_HIGH_EXPLOSIVE_BURN 0 TYPE 9 MAT_NULL 0 TYPE 10 MAT_ELASTIC_PLASTIC_HYDRO 0 TYPE 11 MAT_STEINBERG 0 TYPE 12 MAT_ISOTROPIC_ELASTIC_PLASTIC 0 2 3 TYPE 13 MAT_ISOTROPIC_ELASTIC_FAILURE 0 TYPE 14 MAT_SOIL_AND_FOAM_FAILURE 0 TYPE 15 MAT_JOHNSON_COOK 0 2 TYPE 16 MAT_PSEUDO_TENSOR 0 TYPE 17 MAT_ORIENTED_CRACK 0 TYPE 18 MAT POWER LAW PLASTICITY 0 1H 2 3 19 MAT STRAIN RATE DEPENDENT PLASTICITY 0 2 3 TYPE 20 MAT RIGID 0 1H 1B 1T 2 3 21 ORTHOTROPIC THERMAL 0 2 3 LS DYNA3D Version 936 19 1 MAT MAT 22 MAT COMPOSITE DAMAGE 0 2 3 23 TEMPERATURE DEPENDENT ORTHOTROPIC 0 2 3 TYPE 24 MAT PIECEWISE LINEAR PLASTICITY 0 1H 2 3 TYPE 25 MAT GEOLOGIC 0 TYPE 26 HONEYCOMB 0 27 MAT MOONEY RIVLIN RUBBER 0 2 TYPE 28 MAT_RESULTANT_PLASTICITY 1B 2 TYPE 29 MAT_FORCE_LIMITED 1B TYPE 30 MAT_CLOSED_FORM_SHELL_PLASTICITY 2 3 TYPE 31 MAT_FRAZER NASH_RUBBER 0 32 LAMINATED GLASS 2 3 TYPE 33 MAT_BARLAT_ANISOTROPIC_PLASTICITY 0 2 3 TYPE 34 MAT_FABRIC 4 35 PLASTIC GREEN NAGHDI RATE 0 TYPE 36 MAT 3 PARAMETER BARLAT 2 TYPE37 MAT TRANSVERSELY ANISOTROPIC ELASTIC PLASTIC 2 3 TYPE 38 MAT_BLATZ KO_FOAM 0 2 TYPE 39 MAT_FLD_TRANSVERSELY_ANISOTROPIC 2 3 TYPE 40 MAT_NONLINEAR_ORTHOTROPIC 2 TYPE 41 50 MAT_USER_DEFINED_MATERIALS TYPE 51 M
168. BULATED 10 EOS PROPELLANT DEFLAGRATION TYPE 1I EOS TENSOR PORE COLLAPSE LS DYNA3D Version 936 12 1 EOS EOS EOS LINEAR POLYNOMIAL Purpose Define coefficients for linear polynomial EOS Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Type VARIABLE DESCRIPTION EOSID Equation of state label CO C2 C3 C4 C5 C6 E0 Initial internal energy vo Initial relative volume 12 2 EOS LS DYNA3D Version 936 EOS The linear polynomial equation of state is linear in internal energy The pressure is given by E 2 3 2 CU cp cui where terms and are set to zero if i 0 Rx ES is the ratio of current 0 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 Cp C3 0 and C4 Cs 1 where is the ratio of specific heats The pressure is then given by Bote The units of E are the units of pressure LS DYNA3D Version 936 12 3 EOS EOS EOS JWL This is Equation of state Form 2 Card Format VARIABLE DESCRIPTION EOSID Equation of state label A B R2 OMEG 0 VO The JWL equation of state defines the pressure as RV 1 1 B 1 2 R V R V 1 2 V and is usually used for detonation products of high explosives 12
169. Blank thickness 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 2 Scale factor for true thickness optional g3 Load curve ID defining thickness versus time optional GEOTYP 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 5 24 CONTACT LS DYNA3D Version 936 CONTACT X IGTYPE 1 Infinite Plane IGTYPE 2 Sphere Z 0 b X X n Y n 7 n 22 b 3 Infinite Cylinder IGTYPE 4 Hyperellipsoid Figure 5 3a Contact Entities LS DYNA3D Version 936 5 25 CONTACT CONTACT IGTYPE 5 Torus IGTYPE 10 Finite Plane Z axis of symmetry Load Curve x IGTYPE 11 Load Curve Figure 5 3b Contact Entities 5 26 CONTACT LS DYNA3D Version 936 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 Default 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 displacement EXP Exponent in damage curve With this option t
170. C3 FRIC4 NINPUT UA SIDE Qe ke ee he e he e e e se he e he e e k e k e k k he k e k se k k he k e k k k k he k e k k k k ke k he k k k k ke k ke k k k k k k k k e k kk k C LIVERMORE SOFTWARE TECHNOLOGY CORPORATION LSTC a ie ae ot eR en a Eee ME E COPYRIGHT 1987 1988 1989 JOHN HALLQUIST LSTC C ALL RIGHTS RESERVED Qe ke ke e he e e e e e e he e he e e k e k e he k he k e k Se k k he k e k se k k he k e e k k k he k he k k k k ke k e k k k k k k e kkk kkk INTEGER CYCLE CHARACTER SIDE DIMENSION UA MASTRS 4 XCM 4 YCM 4 ZCM 4 USER SUBROUTINE FOR INTERFACE FRICTION CONTROL NOTE LS DYNA3D USES INTERNAL NUMBERING SYSTEM ACCOMODATE ARBITRARY NODE NUMBERING ACCESS INFORMATION FOR USER NODE ADDRESS ARRAY LOCATION M LQF N 1 OBTAIN USER NODE NUMBER CORRESPONDING TO ARRAY ADDRESS M SET N LQFINV M 1 ARGUMENTS NSI NUMBER OF SLIDING INTERFACE CURRENT SOLUTION TIME CYCLE CYCLE NUMBER DT2 TIME STEPS SIZE AT N 1 2 NSLAVE SLAVE NODE NUMBER IN LS DYNA3D INTERNAL NUMBERING AREAS SLAVE NODE AREA INTERFACE TYPES 5 amp 10 ONLY XS X COORDINATE SLAVE NODE PROJECTED 5 Y COORDINATE SLAVE NODE PROJECTED 25 Z COORDINATE SLAVE NODE PROJECTED MSN MASTER SEGMENT NUMBER MASTRS 4 MASTER SEGMENT NODE LS DYNA3D INTERNAL NUMBERING AREAM MA
171. CE ERODING SURFACE TO SURFACE ERODING SINGLE SURFACE NODES TO SURFACE 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 TIEBREAK NODES TO SURFACE TIEBREAK SURFACE TO SURFACE TIED NODES TO SURFACE TIED SHELL EDGE TO SURFACE TIED SURFACE TO SURFACE 5 3 CONTACT CONTACT Remarks 1 TIED_NODES_TO_SURFACE TIED_SHELL_EDGE_TO_SURFACE TIED_SURFACE_TO_SURFACE These contact definitions are based on constraint equations and will not work with rigid bodies It is suggested to use the CONSTRAINED_EXTRA_NODE_OPTION instead 2 CONSTRAINT NODES TO SURFACE CONSTRAINT SURFACE TO SURFACE These contact definitions have to 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 a CONSTRAINT type the other one could be a standard penalty type such as SURFACE TO SURFACE or NODES TO SURFACE 3 AIRBAG_SINGLE_SURFACE 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 elem
172. D Version 936 19 15 MAT MAT MAT ELASTIC PLASTIC THERMAL This is Material Type 4 Temperature dependent material coefficients can be defined A maximum of eight temperatures with the corresponding data can be defined A minimum of two points is needed Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 Card 4 19 16 MAT LS DYNA3D Version 936 MAT Card Format no defaults are assumed Card 5 ALPHA ALPHA2 ALPHA3 ALPHA4 5 ALPHA6 ALPHA7 ALPHA8 Card 6 1 2 3 4 5 6 8 SIGY4 SIGY5 SIGY6 SIGY7 Card 7 ETAN4 ETANS ETAN6 ETAN7 releja VARIABLE DESCRIPTION MID Material identification A unique number must be chosen RO Mass density TI Temperatures The minimum is 2 the maximum is 8 EI Corresponding Young s moduli at temperature TI PRI Corresponding Poisson s ratios ALPHAI Corresponding coefficients of thermal expansion SIGYI Corresponding yield stresses ETANI Corresponding plastic hardening moduli LS DYNA3D Version 936 19 17 MAT MAT At least two temperatures and their corresponding material properties must be defined The analysis will be terminated if a material temperature falls outside the range defined in the input If a thermoelastic material is considered do not define SIGY and ETAN The coefficient of thermal expansion is defined with respect to the reference temperature at the beginning of the calculation for the material Thus the thermal
173. DESCRIPTION Exponent for normal force Exponent for shear force Failure criterion NEN MES 4 SFLF Failure is assumed if the left side is larger than 1 4n and 4s are the normal and shear interface force Normal failure stress Shear failure stress Failure criterion esl Y los Y CNN BC d 2 1 NFLS SFLS 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 Load curve ID giving force versus deflection behavior for RIGID_ contact See also the definition of FCM below 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 Unloading stiffness for RIGID contact The default is to unload along the loading curve This should not be larger than the maximum value used in the loading curve Conductivity of fluid in gap Radiation conductance across gap Heat transfer coefficient Critical gap For gaps less than GCRIT the heat transfer coefficient is used For gaps greater than GCRIT the conductivity of fluid in the gap is used
174. DYNA3D Version 936 INTRODUCTION EXECUTION SYNTAX The interactive execution line for LS DYNA3D is as follows LS DYNA3D I inf O otf G ptf D dpf F thf U xtf T tpf A rrd M sif J jif S iff Z isf1 L isf2 B rlf W root E efl X scl C cpu K kill V vda Y c3d KEYWORD MEMORY nwds where inf otf ptf dpf thf xtf tpf rrd sif jif iff isfl isf2 rif efl root cpu kill vda c3d nwds input file user specified high speed printer file defaultZD3HS P binary plot file for graphics defaultZD3PLOT dump file for restarting default D3DUMP binary plot file for time histories of selected data defaultZD3THDT binary plot file for time extra data default XTFILE optional temperature file TOPAZ3D plotfile running restart dump file default RUNRSF stress initialization file user specified optional JOY interface file interface force file user specified interface segment save file to be created user specified existing interface segment save file to be used user specified binary plot file for dynamic relaxation default D3DRFL echo file containing optional input echo with or without node element data root file name for general print option scale factor for binary file sizes default 7 cpu limit in seconds applies to total calculation not just cpu from a restart if LS DYNA3D encounters this file name it will terminate with a restart file default D3KIL VDA IGES database for geometrica
175. DYNA3D Version 936 29 29 RESTART RESTART For the CONTROL option define the following card Card Format Default 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 EQ 0 no change EQ 1 delete EQ 2 activate DTMAX Maximum permitted time step size after restart 29 30 RESTART LS DYNA3D Version 936 RESTART For the D2R option define the following card Termination of this input is when the next card is read Card Format Variable Type Default 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 Variable Type Default VARIABLE DE
176. Default is same as at node 1 Scale factor for plastic moment versus rotation curve about s axis at node 2 Default is same as at node 1 Yield moment about s axis at node 1 for interaction calculations default set to 1 0E 20 to prevent interaction Yield moment about s axis at node 2 for interaction calculations default set to YMS1 Load curve ID for plastic moment versus rotation about t axis at node 1 If Zero this load curve is ignored Scale factor for plastic moment versus rotation curve about t axis at node 1 Default 1 0 Load curve ID for plastic moment versus rotation about t axis at node 2 Default is the same as at node 1 Scale factor for plastic moment versus rotation curve about t axis at node 2 Default is the same as at node 1 19 91 MAT MAT VARIABLE DESCRIPTION YMTI Yield moment about t axis at node 1 for interaction calculations default set to 1 0E 20 to prevent interactions YMT2 Yield moment about t axis at node 2 for interaction calculations default set to YMTI LPR Load curve ID for plastic torsional moment versus rotation If zero this load curve is ignored SFR Scale factor for plastic torsional moment versus rotation default 1 0 YMR Torsional yield moment for interaction calculations default set to 1 0E 20 to prevent interaction This material model is available for the Belytschko resultant beam element only Plastic hinges form at the ends of the beam when the moment r
177. E BINARY Purpose Specify output database to be written Binary applies to the data written to the D3PLOT 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 number For the corresponding VTYPE integer components from the following tables can be chosen 0 Table 8 1 VTYPE EQ 1 Table 8 2 VTYPE EQ 2 not supported VTYPE EQ 3 Table 8 3 VTYPE EQ 4 not supported LS DYNA3D Version 936 8 9 DATABASE DATABASE 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 organization is relatively transparent The MOVIE and MPGS database are widely used and will be familiar with users who ar
178. 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 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 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 Velocity Acceleration Displacement flag EQ 0 velocity rigid bodies and nodes EQ 1 acceleration nodes only EQ 2 displacement rigid bodies and nodes Load curve ID to describe motion value versus time see DEFINE CURVE Load Curve Scale Factor Vector ID for DOF values of 4 or 8 see DEFINE VECTOR Time imposed motion constraint is removed EQ 0 0 default set to 1028 Offset for DOF types 9 11 y z x direction Offset for DOF types 9 11 z x y direction Abitrary 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 LS DYNA3D Version 936 3 11 BOUNDARY BOUNDARY BOUNDARY PRESSURE OUTFLOW OPTION Available options are SEGMENT SET Purpose Define pressure outflow boundary conditions These bounday condit
179. EQ 1 deviatoric plastic strain B Residual strength factor after cracking see Figure 19 21 FAIL Flag for failure EQ 0 no failure EQ 1 failure when pressure reaches failure pressure element loses it ability to carry tension Pressure is positive in compression Volumetric strain is defined as the natural log of the relative volume and is positive in compression where the relative volume V is the ratio of the current volume to the initial volume The tabulated data should be given in order of increasing compression If the pressure drops below the cutoff value specified it is reset to that value and the deviatoric stress state is eliminated If the load curve ID LCYP is provided as a positive number the deviatoric perfectly plastic pressure dependent yield function is given as 4 37 F p where F p is a tabulated function of yield stress versus pressure and the second invarient Jo is defined in terms of the deviatoric stress tensor as 1 Ja 5 2545 ij assuming that If the ID is given as negative then the yield function becomes J5 F p being the deviatoric stress tensor If cracking is invoked by setting the residual strength factor on card 2 to a value between 0 0 and 1 0 the yield stress is multiplied by a factor f which reduces with plastic strain according to a trilinear law as shown in Figure 19 21 19 198 MAT LS DYNA3D Version 936 MAT 1 0 j 25 p
180. ERATION rette ere et ete tek estou bladed tee v ten tet L40 LS TAURUS POST PROCESSINQG niei ee 1 41 EXECUTION SPEEDS IRR RII E 1 43 UNITS 1 ie to o to ere d tous e Met boys o He e e HP Eoo re Ee 1 45 GENERAL CARD FORMA 202 L46 MPP LS DYNA3D USER INFORMATION 1 47 sounssvassonsvenssonssoasevasvuassoassuaseunsibesdoasubasusnsieestsasvbasdonsubecdudgvoassonsunsensveees 1 1 EGRESSUS RICHIE SU 1 1 AIRBAG INTERACTION rm I a e e teas reve 1 19 AIRBAG REFERENCE GEOMETRY 1 1 20 TAL om M M 2 1 OG ROTER peres 24 BOUNDARY 3 1 BOUNDARY CONVECTION 2 002022000 01 0000 0000000 3 2 BOUNDARY CYCLIGC SEE PRSE 3 4 BOUNDARYX EEUX OPTION ree e e DER ear REE Lo cue a UL aen 3 6 BOUNDARY NON REFLECTING he Re e 3 9 LS DYNA3D Version 936 1 TABLE OF CONTENTS BOUNDARY PRESCRIBED MOTION OPTION eese eene hee 3 10 BOUNDARY PRESSURE OUTFLOW
181. ES i soiis ieaiai no ai E EE nnne nennen enne nennen eene 9 3 DEFINE COORDINATE SYSTEM niece e pee P EP P 9 4 DBFINE COORDINATE VECTOR t tr e her PIU PIT 9 6 DEFINE CUR VE x enm HH e E E EU ese e ve re ve pesi lees 9 7 DEEINE SD ORIENTATION cost sch ptu preti ete e repete eet goce tie pee eerte teg rete 9 9 LS DYNA3D Version 936 iii TABLE OF CONTENTS DEEFINE TABLE neue seemed ecd 9 10 DBEINE VECTOR uh RR 9 12 DEFORMABLE RIGID 4 eere 10 1 DEFORMXABLE TO RIGID 5 EEE crsbacceersscopeensbocenseeneg 10 2 DEFORMABLE TO RIGID 10 3 DEFORMABLE TO RIGID INERTIA prre eere cre erre eret 10 7 11 1 ELEMENT BEAM OPTION E 11 2 ELEMENT DISCRETE eerte iet EE EEEE EREE OEE NS 11 5 ELEMEN T MASS tu eet tte toe ete e t tee t AE E ede he 11 6 ELEMENT SEATBBELT ntt tr e ee n 11 7 ELEMENT SEATBELT 4 eterne hee 11 8 ELEMENT SEATBELT PRETENSIONER 11 9 ELEMENT SEATBELT 11 11 BELEMENT SEATBELT SENSOR siipien e ep Ee ete eei
182. EWISE LINEAR PLASTICITY This is Material Type 24 An elasto plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency can be defined See also Remark below Also failure based on a plastic strain or a minimum time step size can be defined Card Format Card 1 1 2 3 4 5 6 7 8 10 20 10 20 2 3 LS DYNA3D Version 936 19 67 MAT MAT Card 4 Variable Type Default VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Tangent modulus ignored if LCSS GT 0 is defined EPPF Plastic strain at failure logrithmic TDEL Minimum time step size for automatic element deletion C Strain rate parameter C see formula below P Strain rate parameter P see formula below LCSS Load curve ID or Table ID Load curve ID defining effective stress versus effective plastic strain If defined EPS1 EPS8 and ES1 ES8 are ignored The table ID defines for each strain rate value a load curve ID giving the stress versus effectiveplastic strain for that rate See Figure 19 5 The stress versus effective plastic strain curve for the lowest value of strain rate is used if the strain rate falls below the minimum value Likewise the stress versus effective plastic strain curve for the highest value of strain rate is used if the strain rate exceeds the m
183. Element Analysis Using Compressive Uniaxial and Triaxial Data SAE Nat Conf Detroit 1993 pp 4 34 Brode H L Height of Burst Effects at High Overpressure RAND RM 6301 DASA DASA 2506 1970 Brown B E and J O Hallquist TAURUS An Interactive Post Processor for the Analysis Codes NIKE3D DYNA3D TACO3D and GEMINI University of California Lawrence Livermore National Laboratory Rept UCID 19392 1982 Rev 1 1984 Burton D E et al Physics and Numerics of the TENSOR Code Lawrence Livermore National Laboratory Internal Document UCID 19428 July 1982 Chang and Chang A Progressive Damage Model for Laminated Composites Containing Stress Concentration J of Composite Materials 21 834 855 1987a Chang F K and K Y Chang Post Failure Analysis of Bolted Composite Joints in Tension or Shear Out Mode Failure J of Composite Materials 21 809 833 1987b Chung K and K Shah Finite Element Simulation of Sheet Metal Forming for Planar Anisotropic Metals Int J of Plasticity 8 453 476 1992 Cochran S G and J Chan Shock Initiation and Detonation Models in One and Two Dimensions University of California Lawrence Livermore National Laboratory Rept UCID 18024 1979 Couch R E Albright and N Alexander The Joy Computer Code Lawrence Livermore National Laboratory Internal Document Rept UCID 19688 January 1983 CRAY 1 Co
184. Figure 19 21 Strength reduction factor b residual strength factor j plastic stain at which cracking begins 2 plastic stain at which residual strength is reached and are tabulated function of pressure that are defined by load curves see Figure 19 22 The values on the curves are pressure versus strain and should be entered in order of increasing pressure The strain values should always increase monotonically with pressure By properly defining the load curves it is possible to obtain the desired strength and ductility over a range of pressures see Figure 19 23 P Figure 19 22 Cracking strain versus pressure LS DYNA3D Version 936 19 199 MAT MAT Figure 19 23 19 200 MAT LS DYNA3D Version 936 MAT MAT HYSTERETIC SOIL This is Material Type 79 This model is a nested surface model with five superposed layers of elasto perfectly plastic material each with its own elastic moduli and yield values Nested surface models give hysteric behavior as the different layers yield at different stresses See notes below 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 Card 4 1 2 3 4 5 6 7 8 LS DYNA3D Version 936 19 201 MAT MAT VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density KO Bulk modulus at the reference pressure PO Cut off datum pressure must be 0 lt i e tensile Bel
185. HLF VT 3 NSV I X1 XI 1 NSV I 4DSP1 X2 XI 2 NSV I YDSP2 X3 XI 3 NSV I DSP3 THKS MAX THSV I THKS XMINS MIN XMINS X1 XMAXS MAX XMAXS X1 YMINS MIN YMINS X2 YMAXS MAX YMAXS X2 ZMINS MIN ZMINS X3 ZMAXS MAX ZMAXS 10 CONTINUE DO 20 I 1 NMN DSP1 UT 1 MSR I DT2HLF VT 1 MSR I DSP2 UT 2 MSR I DT2HLF VT 2 MSR I DSP3 UT 3 MSR I DT2HLF VT 3 MSR I X1 XI 1 MSR I 4DSP1 X2 XI 2 MSR I 4DSP2 X3 XI 3 MSR I 4DSP3 THKM MAX THMR I THKS XMINS MIN XMINM X1 XMAXS MAX XMAXM X1 YMINS MIN YMINM X2 YMAXS MAX YMAXM X2 ZMINS MIN ZMINM X3 ZMAXS MAX ZMAXM X3 20 CONTINUE IF XMAXS4THKS LT XMINM THKM GO 40 IF YMAXS4THKS LT YMINM THKM GO TO 40 D 2 LS DYNA3D Version 936 IF ZMAXS THKS LT ZMINM THKM IF XMAXS THKM LT XMINS THKS IF YMAXS THKM LT YMINS THKS IF ZMAXS THKM LT ZMINS THKS ISKIP 0 RETURN 40 ISKIP 1 RETURN END LS DYNA3D Version 936 GO TO 40 GO TO 40 GO TO 40 GO TO 40 Appendix D D 3 Appendix E APPENDIX E User Defined Interface Friction This subroutine may be provided by the user to set the Coulomb friction coefficients This option is activated by the USER INTERFACE FRICTION keyword The arguments are defined in the listing provided below SUBROUTINE USRFRC NSI TIME CYCLE DT2 NSLAVE AREAS XS YS ZS MSN MASTRS AREAM XCM YCM ZCM STFSN STFMS FORCEN RVY RVZ FRIC1 FRIC2 FRI
186. IP layers of equal thickness S 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 1 the weighting E Atj factor for the ith integration point as seen in Figure 16 4 Not necessary if ESOP 1 PID Optional part ID if different from the ID specified on the element card The material type is not allowed to change see PART 16 6 INTEGRATION LS DYNA3D Version 936 INTEGRATION midsurface Figure 16 4 In the user defined shell integration rule the ordering of the integration points is arbitrary LS DYNA3D Version 936 16 7 INTEGRATION 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 isf1 on the execution command line 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 I
187. IRBAG 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 This section applies to various methods of specifying either fixed or prescribed boundary conditions For compatibility with older versions of LS DYNA3D it is still possible to specify some nodal boundary conditions in the NODE card section 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 base on plastic strain The 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 ve
188. ITIAL LS DYNA3D Version 936 Figure 15 1 INITIAL VARIABLE DESCRIPTION PEAK Peak pressure po of incident pressure pulse see remark below DECAY Decay constant 7 XS x coordinate of standoff point see Figure 15 1 YS y coordinate of standoff point ZS z coordinate of standoff point NID Reference node ID near structure Remark t 1 The pressure versus time curve is defined by p t Poe T Pressure profile at standoff point Standoff point Structure 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 Initialization of the initial pressures due to an explosive disturbance is performed in the acoustic media LS DYNA3D 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 LS DYNA3D Version 936 15 3 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 Variable Type Default VARIABLE DESCRIPTION EID Element ID MX Initial x momentum MY Initial y momentum MZ Initial zzmomentum DEPT Deposition time 15 4 INITIAL LS DYNA3D Version 936 INITIAL INITIAL STRESS BEAM Purpose Initi
189. Implementation of the Hughes Liu Shell Finite Element Methods for Plate and Shell Structures T J R Hughes and E Hinton Editors 394 431 Pineridge Press Int Swanea U K 1986 Hallquist J O and D J Benson DYNA3D User s Manual Nonlinear Dynamic Analysis of Solids in Three Dimensions University of California Lawrence Livermore National Laboratory Rept UCID 19156 Rev 2 1986 Rev 3 1987 Hallquist J O D W Stillman T J R Hughes C and Tarver Modeling of Airbags Using MVMA DYNA3D LSTC Report 1990 Herrmann L R and F E Peterson A Numerical Procedure for Viscoelastic Stress Analysis Seventh Meeting of ICRPG Mechanical Behavior Working Group Orlando FL CPIA Publication No 177 1968 Hill R A Theory of the Yielding and Plastic Flow of Anisotropic Metals Proceedings of the Royal Society of London Series A Vol 193 1948 pp 281 197 Hill R Constitutive Modelling of Orthotropic Plasticity in Sheet Metals J Mech Phys Solids Vol 38 No 3 1989 pp 405 417 Hughes T J R and W K Liu Nonlinear Finite Element Analysis of Shells Part I Three Dimensional Shells Comp Meths Appl Mechs 27 331 362 1981 Hughes T J R and W K Liu Nonlinear Finite Element Analysis of Shells Part II Two Dimensional Shells Comp Meths Appl Mechs 27 167 181 1981b Hughes T J R W K Liu and I Levit Nonlinear Dynamics Finite Element Analysis of Shells Nonlinear Finit
190. Key 1974 e high explosive burn e hydrodynamic without deviatoric stresses e elastoplastic hydrodynamic e temperature dependent elastoplastic Steinberg and Guinan 1978 e isotropic elastoplastic e isotropic elastoplastic with failure e soil and crushable foam with failure e Johnson Cook plasticity model Johnson and Cook 1983 e pseudo TENSOR geological model Sackett 1987 e elastoplastic with fracture e power law isotropic plasticity e strain rate dependent plasticity e rigid e thermal orthotropic composite damage model Chang and Chang 1987a 1987b e thermal orthotropic with 12 curves e piecewise linear isotropic plasticity e inviscid two invariant geologic cap Sandler and Rubin 1979 Simo et al 1988a 1988b orthotropic crushable model e Mooney Rivlin rubber e resultant plasticity e force limited resultant formulation closed form update shell plasticity e Frazer Nash rubber model 1 20 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION e laminated glass model e fabric e unified creep plasticity e temperature and rate dependent plasticity e elastic with viscosity e anisotropic plasticity e user defined crushable cellular foams Neilsen Morgan and Krieg 1987 e urethane foam model with hystersis 1992 and some more foam and rubber models as well as many materials models for springs and dampers The hydrodynamic material models determine only the de
191. LE 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 LS DYNA3D Version 936 24 9 SET SET VARIABLE DESCRIPTION N1 Nodal point nj N2 Nodal point N3 Nodal point n3 N4 Nodal 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 Remarks 1 Segment attributes can be assigned for some input types For example for the contact options the attributes for the SLAVE surface are DA1 NFLS Normal failure stress CONTACT_TIEBREAK_ 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 DA1 FSF Coulomb friction scale factor DA2 VSF Viscous friction scale factor For airbags see AIRBAG a time delay DAI TI 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 3 The default segment attributes c
192. LETE OPTION INTERFACE SPRINGBACK RIGID DEFORMABLE 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 LS DYNA3D Version 936 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 DYNA3D Version 936 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 t
193. LOCAL Y STRAIN EPS 3 LOCAL Z STRAIN EPS 4 LOCAL XY STRAIN EPS 5 LOCAL YZ STRAIN EPS 6 LOCAL ZX STRAIN EPS 1 LOCAL X STRAIN SIG 1 LOCAL X STRESS SIG 2 LOCAL Y STRESS SIG 3 LOCAL Z STRESS QQQQ00000000000300000n0n LS DYNA3D Version 936 Appendix A SIG 4 LOCAL XY STRESS SIG 5 LOCAL YZ STRESS SIG 6 LOCAL ZX STRESS HISV 1 1ST HISTORY VARIABLE HISV 2 2ND HISTORY VARIABLE HISV N NTH HISTORY VARIABLE SHALL NOT EXCEED VALUE GIVEN IN MAT USER DEFINED MATERIAL MODELS DT1 CURRENT TIME STEP SIZE CAPA REDUCTION FACTOR FOR TRANSVERSE SHEAR ETYPE EQ BRICK FOR SOLID ELEMENTS EQ SHELL FOR ALL SHELL ELEMENTS EQ BEAM FOR ALL BEAM ELEMENTS TIME CURRENT PROBLEM TIME ALL TRANSFORMATIONS INTO THE ELEMENT LOCAL SYSTEM ARE PERFORMED PRIOR TO ENTERING THIS SUBROUTINE TRANSFORMATIONS BACK TO THE GLOBAL SYSTEM ARE PERFORMED AFTER EXITING THIS SUBROUTINE ALL HISTORY VARIABLES ARE INITIALIZED TO ZERO IN THE INPUT PHASE INITIALIZATION OF HISTORY VARIABLES TO NONZERO VALUES MAY BE DONE DURING THE FIRST CALL TO THIS SUBROUTINE FOR EACH ELEMENT ENERGY CALCULATIONS FOR THE DYNA3D ENERGY BALANCE ARE DONE OUTSIDE THIS SUBROUTINE QQQQ000000000000300000000000n0nqoooonqn CHARACTER ETYPE DIMENSION CM EPS SIG HISV COMPUTE SHEAR MODULUS G G2 CM 1 1 CM 2 G 5 G IF ETYPE EQ BRICK THEN DAVG EPS 1 EPS 2 EPS 3 3 P DAVG CM 1 1 2 CM 2 SIG 1
194. LS DYNA3D Version 936 RESTART The STATUS REPORT FREQUENCY option allows the output status interval to be changed Card Format VARIABLE DESCRIPTION IKEDIT Problem status report interval steps in the D3HSP output file EQ 0 interval remains unchanged LS DYNA3D Version 936 29 9 RESTART 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 29 10 RESTART LS DYNA3D Version 936 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 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 VELOCITY ZERO cards are defined then all velocities will be reset to zero LS DYNA3D Version 936 29 11 RESTART RESTART The THERMAL PARAMETERS option allows parameters used by a thermal or couple
195. LS DYNA3D Version 936 6 1 CONTROL CONTROL CONTROL ADAPTIVE Purpose Activate adaptive meshing The parts which are adaptively meshed are defined by PART Card Format Variable ADPFREQ ADPTOL ADPOPT MAXLVL TBIRTH TDEATH LCADP IOFLAG Default VARIABLE DESCRIPTION ADPFREQ Time interval between adaptive refinements see Figure 6 1 ADPTOL Adaptive error tolerance in degrees see also option ADPOPT below ADPOPT Adaptive options EQ 1 angle change in degrees per adaptive refinement relative to the surrounding elements for each element to be refined 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 MAXLVL Maximum number of refinement levels Values of 1 2 3 allow a maximum of 4 16 64 elements respectively to be created for each original element TBIRTH Birth time at which the adaptive remeshing begins see Figure 6 1 TDEATH Death time at which the adaptive remeshing ends see Figure 6 1 LCADP Adaptive interval is a function of time given by load curve ID LCADP If this option is nonzero the adpfreq will be replaced by LCADP IOFLAG Flag to generate adaptive mesh at exit including NODE ELEMENT SHELL and BOUNDARY_ CONTACT
196. LS DYNA3D shell elements Counterclockwise node numbering determines the top surface Figure 11 6 Orientation of material directions relative to the 1 2 side 11 26 ELEMENT LS DYNA3D Version 936 ELEMENT i Figure11 7 A multi layer laminate can be defined The angle D is defined for the ith lamina integration point see SECTION SHELL LS DYNA3D Version 936 11 27 ELEMENT ELEMENT ELEMENT SOLID OPTION Available options include BLANK ORTHO Purpose Define a solid element The type of solid element has to be specified via PART and SECTION SOLID OPTION Also a local coordinate system for orthotropic and anisotropic materials can be defined Card Format 1018 Variable Type 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 7 8 9 10 Variable Type Remarks 11 28 ELEMENT LS DYNA3D Version 936 ELEMENT Optional card 2 1 2 3 4 5 6 7 8 9 10 Variable Type Default Remarks VARIABLE DESCRIPTION EID Element ID A unique number has to be chosen PID Part ID see PART N1 Nodal point 1 N2 Nodal point 2 N3 Nodal point 3 N8 Nodal point 8 Al x component of local material direction a A2 y component of local material direction a A3 z component of local material direction a D1 x component of vector in the plane of the material vectors a and b D2 y compone
197. MAT LS DYNA3D Version 936 MAT MAT CLOSED CELL FOAM This is Material Type 53 This allows the modeling of low density closed cell polyurethane foam It is for simulating impact limitors in automotive applications The effect of the confined air pressure is included with the air being treated as an ideal gas The general behavior is isotropic with uncoupled components of the stress tensor Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type Card 2 Variable GAMAO Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus A a factor for yield stress definition see notes below B b factor for yield stress definition see notes below C c factor for yield stress definition see notes below PO Initial foam pressure Po PHI Ratio of foam to polymer density GAMAO Initial volumetric strain Yo The default is zero LS DYNA3D Version 936 19 135 MAT MAT A rigid low density closed cell polyurethane foam model developed at Sandia Laboratories Neilsen et al 1987 has been recently implemented for modeling impact limiters in automotive applications A number of such foams were tested at Sandia and reasonable fits to the experimental data were obtained In some respects this model is similar to the crushable honeycomb model type 26 in that the components of the stress tensor are uncoupled until full volumetric compaction is achieved However
198. MPLE PRESSURE VOLUME SIMPLE AIRBAG MODEL ADIABATIC GAS MODEL WANG NEFSKE WANG NEFSKE JETTING WANG NEFSKE MULTIPLE JETTING LOAD CURVE LINEAR FLUID Purpose Define an airbag or control volume LS DYNA3D Version 936 1 1 AIRBAG AIRBAG Card Format Variable SID SIDTYP VSCA PSCA VINI MWD SPSF VARIABLE DESCRIPTION SID Set ID SIDTYP Set type EQ 0 segment NE 0 part IDs RBID Rigid body ID for user defined activation subroutine EQ 0 the control volume is active from time zero EQ n user sensor subroutine flags the start of the inflation Load curves are offset by initiation time See Appendix B VSCA Volume scale factor default 1 0 PSCA Pressure scale factor Psca default 1 0 VINI Initial filled volume Vini MWD Mass weighted damping factor D SPSF Stagnation pressure scale factor O lt y 1 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 material subset which represents shell elements which form the closed boundary All polygon normals must be oriented to face outwards from the control volume If holes are detected they ar
199. MT ESPS FMPS CONSTRAINED DESCRIPTION Load curve ID for moment versus rotation in radians See Figure 4 5 If zero the applied moment is set to 0 0 See DEFINE CURVE Load curve ID for 0 moment versus rotation in radians If zero the applied moment is set to 0 0 See DEFINE CURVE Load curve ID for y moment versus rotation in radians If zero the applied moment is set to 0 0 See DEFINE CURVE Load curve ID for damping moment versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE Load curve ID for 0 damping moment versus rate of rotation in radians per unit time If zero damping is not considered See DEFINE CURVE 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 Elastic stiffness per unit radian for friction and stop angles for rotation See Figure 4 6 If zero friction and stop angles are inactive for rotation 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 4 6 Elastic stiffness per unit radian for friction and stop angles for 0 rotation See Figure 4 6 If zero friction and stop angles are inactive for
200. N EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector XP YP ZP Coordinates of point p for AOPT 1 Al A2 Components of vector a for AOPT z 2 V1 V2 V3 Components of vector v for AOPT 3 D1 D2 D3 Components of vector d for AOPT 2 The yield function is defined as 151 521 182 9310 153 5110 26 m where is the effective stress and Sj 1 2 3 are the principal values of the symmetric matrix Sog Sxx C Oxx b oz 1 3 Syy 6072 C Oxx 3 Szz b oz 0721 3 Syz f Oyz Szx 8 The material constants a b c f g and h represent anisotropic properties When a b c f g h 1 the material is isotropic and the yield surface reduces to the Tresca yield surface for m 1 and von Mises yield surface for m 2 or 4 For face centered cubic FCC materials m 8 is recommended and for body centered cubic BCC materials m 6 is used The yie
201. N NO RIGID BODIES PRESENT NOTE IN BLANK COMMENT VR FOLLOWS VT THIS FACT IS USED BELOW DO 10 1 2 XMSN 1 XMST N VN1 VT 1 N VN2 VT 2 N VN3 VT 3 N XM XM4XMSN VN1 YM YM XMSN VN2 ZM ZM XMSN VN3 XKE XKE XMSN VN1 VN1 VN2 VN2 VN3 VN3 CONTINUE ELSE RIGID BODIES PRESENT DO 20 N 1 NUMNP XMSN 1 XMST VN1 RBDYN N VT 1 N VN2 RBDYN N VT 2 N VN3 RBDYN N VT 3 N XM XM XMSN VN1 YM YM XMSN VN2 ZM ZM XMSN VN3 XKE XKE XMSN VN1 VN1 VN2 VN2 VN3 VN3 CONTINUE IF NDOF EQ 6 THEN DO 30 N 1 NUMNP XMSN 1 XMSR VN1 RBDYN N VR 1 N LS DYNA3D Version 936 C 3 Appendix C QQQQ00000n0 C4 30 VN2 RBDYN N VR 2 N VN3 RBDYN N VR 3 N XM XM XMSN VN1 YM YM XMSN VN2 ZM ZM XMSN VN3 XKE XKE XMSN VN1 VN1 VN2 VN2 VN3 VN3 CONTINUE ENDIF ENDIF RETURN END Berar TOTAL KINETIC ENERGY XKE 5 XKE 7 962 TOTAL INTERNAL ENERGY XIE XPE DEENG TOTAL ENERGY XTE XKE XPE DEENG TOTAL X RIGID BODY VELOCITY XRBV XM TOTALM ces He TOTAL Y RIGID BODY VELOCITY YRBV YM TOTALM ih uid TOTAL Z RIGID BODY VELOCITY ZRBV ZM TOTALM RETURN END LS DYNA3D Version 936 Appendix D APPENDIX D User Defined Interface Control This subroutine may be provided by the user to turn the interfaces on and off This option is activated by the USER INTERFACE CONTROL keyword The arguments are defined in the listing provided below
202. NA3D Version 936 19 143 MAT MAT VARIABLE LCID TC HU BETA DAMP SHAPE FAIL BVFLAG ED BETAI KCON DESCRIPTION Load curve ID see DEFINE CURVE for nominal stress versus strain Tension cut off stress Hysteretic unloading factor between 0 and 1 default 1 i e no energy dissipation see also Figure 19 12 decay constant to model creep in unloading Viscous coefficient 05 recommended value 50 to model damping effects Shape factor for unloading Active for nonzero values of the hysteretic unloading factor Values less than one reduces the energy dissipation and greater than one increases dissipation see also Figure 19 12 Failure option after cutoff stress is reached EQ 0 0 tensile stress remains at cut off value EQ 1 0 tensile stress is reset to zero Bulk viscosity activation flag see remark below EQ 0 0 no bulk viscosity recommended EQ 1 0 bulk viscosity active Optional Young s relaxation modulus E for rate effects See comments below Optional decay constant Bj Stiffness coefficient for contact interface stiffness Maximum slope in stress vs strain curve is used When the maximum slope is taken for the contact the time step size for this material is reduced for stability In some cases At may be significantly smaller and defining a reasonable stiffness is recommended The compressive behavior is illustrated in Figure 19 12 where hysteresis on unloading is
203. NERTIA 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 Variable Default Additional Cards are required for the INERTIA option Card 2 1 2 3 4 5 6 7 8 Variable Default LS DYNA3D Version 936 4 25 CONSTRAINED CONSTRAINED Card 3 1 foe e ame Card 4 1 foo oo Optional card required for the IRCS 1 2 3 d 2 3 a 5 1 2 3 4 26 CONSTRAINED LS DYNA3D Version 936 VARIABLE NSID CID XC YC ZC TM IRCS IXX IXY IXZ IYY IYZ 177 VTX VTY VTZ VRX VRY VRZ CONSTRAINED DESCRIPTION Nodal set ID see SET NODE OPTION This nodal set defines the rigid body Coordinate system ID for output of data in local system see DEFINE COORDINATE OPTION Only necessary if no local system is defined below x coordinate of 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 principal moments of inertias with orientation vectors as given below Ixx XX component of inertia tensor Ixy set to zero if IRCS 1 Ixz set to zero if IRCS 1 Iyy yy component o
204. NNR DAN Stress increases at higher strain rates VOLUMETRIC STRAIN Figure 19 13 Behavior of strain rate sensitive crushable foam Unloading is elastic to the tension cutoff Subsequent reloading follows the unloading curve LS DYNA3D Version 936 19 159 MAT MAT RATE SENSITIVE POWERLAW PLASTICITY This is Material Type 64 which will model strain rate sensitive elasto plastic material with a power law hardening Optionally the coefficients can be defined as functions of the effective plastic strain Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus of elasticity PR Poisson s ratio K Material constant If lt 0 the absolute value of k is taken as the load curve number that defines k as a function of effective plastic strain M Strain hardening coefficient m If m 0 the absolute value of m is taken as the load curve number that defines m as a function of effective plastic strain N Strain rate sensitivity coefficient If lt 0 the absolute value of n is taken as the load curve number that defines n as a function of effective plastic strain EO Initial strain rate default 0 0002 This material model follows a constitutive relationship of the form o kemen 19 160 MAT LS DYNA3D Version 936 MAT where the constants k m and n can be expressed as functions of strain or c
205. ON 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 TSMINZDTSTART DTMIN where DTSTART is the initial step size determined by LS DYNA3D 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 ODT2MS Remark 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 DTMIN will be eroded LS DYNA3D Version 936 6 25 CONTROL 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 Format Default VARIABLE DESCRIPTION REFMAX Maximum number of matrix reformations per time step EQ 0 set to 10 reformations TOL Convergence tolerance for temperature EQ 0
206. ON OPTION DATABASE EXTENT OPTION 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 DYNA3D Version 936 8 1 DATABASE DATABASE DATABASE OPTION Options for ASCII files include if the file is not specified it will not be created SECFORC Cross section forces See DATABASE CROSS SECTION OPTION RWFORC Wall forces NODOUT Nodal point data See also DATABASE HISTORY OPTION ELOUT Element data See also DATABASE HISTORY OPTION GLSTAT Global data DEFORC Discrete elements MATSUM Material energies NCFORC Nodal interface forces RCFORC Resultant interface forces DEFGEO Deformed geometry file SPCFORC SPC reaction forces SWFORC Nodal constraint reaction forces spotwelds and rivets ABSTAT Airbag statistics NODFOR Nodal force groups See also DATABASE NODAL FORCE GROUP BNDOUT Boundary condition forces and energy RBDOUT Rigid body data GCEOUT Geometric contact entities SLEOUT Sliding interface energy JNTFORC Joint force file SBTOUT Seat belt output file AVSFEFLT AVS database See also DATABASE EXTENT OPTION MOVIE MOVIE See also DATABASE EXTENT OPTION MPGS MPGS See also DATABASE EXTENT OPTION TRHIST Tracer particle history information See also DATABASE TRACER TPRINT Thermal output from a coupled structural thermal or thermal only an
207. ONTROL CONTROL CPU Purpose Control cpu time Card Format VARIABLE DESCRIPTION CPUTIM Seconds of cpu time EQ 0 0 no cpu time limit set 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 DYNA3D If a value is specified on both the control line and in the input deck the minimum value will be used LS DYNA3D Version 936 6 13 CONTROL CONTROL CONTROL DYNAMIC RELAXATION Purpose Define controls for dynamic relaxation Important for stress initialization Card Format 1 2 3 4 5 6 7 8 mIRC le 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 SCRT defined on CONTROL TIMESTEP After converging the scale factor is reset to SCRT IRELAL Automatic control for dynamic relaxation option based on algorithm of Papad
208. Poisson s ratio DF Damping factor see definition in notes below A proper control for the timestep has to be maintained by the user 19 90 MAT LS DYNA3D Version 936 VARIABLE AOPT YTFLAG ASOFT MI 2 8 LC2 LC8 LPS SFS1 LPS2 SFS2 YMSI YMS2 LS DYNA3D Version 936 MAT DESCRIPTION Axial load curve option EQ 0 0 axial load curves are force versus strain EQ 1 0 axial load curves are force versus change in length Flag to allow beam to yield in tension EQ 0 0 beam does not yield in tension EQ 1 0 beam can yield in tension Axial elastic softening factor applied once hinge has formed When a hinge has formed the stiffness is reduced by this factor If zero this factor is ignored Applied end moment for force versus strain change in length curve At least one must be defined A maximum of 8 moments can be defined The values should be in ascending order Load curve ID see DEFINE CURVE defining axial force versus strain change in length see AOPT for the corresponding applied end moment Define the same number as end moments Each curve must contain the same number of points Load curve ID for plastic moment versus rotation about s axis at node 1 If zero this load curve is ignored Scale factor for plastic moment versus rotation curve about s axis at node 1 Default 1 0 Load curve ID for plastic moment versus rotation about s axis at node 2
209. R value in reference to the ET and R ANSYS keywords 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 DYNA3D Version 936 TRANSLATE TRANSLATE IDEAS OPTION Available options include MASTER Purpose Provide a convenient route to read in files created by IDEAS SUPERTAB as part of the LS DYNA3D keyword input This keyword can appear more than once in the input It is a direct interface to IDEAS universal files Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION FILE Filename of the IDEAS universal file The following table lists supported IDEAS keywords Version SDRC IDEAS Universal File LS DYNA3D Keyword All N Type NODE Val1 Val2 Val3 NODE All EN Type I1 12 13 14 15 I6 17 I8 ELEMENT 5 781 NODE 7 2411 NODE 5 780 ELEMENT 7 2412 ELEMENT 5 773 MAT_ELASTIC 5 772 PART amp SECTION 6 788 PART amp SECTION LS DYNA3D Version 936 27 3 TRANSLATE TRANSLATE Version SDRC IDEAS Universal File 7 2430 5 755 7 791 time variation set le 0 0 time variation set gt 0 0 7 790 load type eq 1 27 4 TRANSLATE LS DYNA3D Keyword PART amp SECTION BOUNDARY SPC NODE BOUNDARY SPC NODE BOUNDARY PRESCRIBED _ MOTION NODE LOAD NODE LS DYNA3D Version 936 TRANSLATE TRANSLATE NASTRAN Purpose Provide a convenient route to read in NASTRAN input deck as part of the LSDYNA3D keyword input This key
210. RE TE mao ms 24 3 SEI NODE OPTION i eicere e ehe te dee pote ere edite eon tede 24 4 PART OPTION heh ere he P E EP P EP DR ER ER as 24 6 TSELSEGMENT tek EADEM eb QE 24 9 SET SHELL OPTION nnn e ee rv e ei re eed Peste ee Pe s 24 11 ep ieget endete erts 24 14 ine eee oett 24 15 MUiUrO 25 1 TUIERMINATION OPTIGON 5 niente din diane eens 25 1 dH HB DRE ERE EE 26 1 TITE E 2641 UP 27 1 TRANSLATE ANS YS OPTION iere treten et rette ret repere eme eode deter 27 1 ERANSLATE IDEAS OPTION pr reet roe pr 27 3 TRANSLATE NASTRAN 27 5 55554 568 000605500690 080000 Y Teo ke ow Y Too 60661000 28 1 USER INTERFACE OPTION rer tot ot Fee ev tetas 28 1 USBR EOADLNQG tnit ertet rre tet tetro eee 28 3 RESTART INPUT 29 1 CHANGE ZOPTION heri er o eR PHOTO OPI dette 29 3 CONTROL DYNAMIC 29 17 CONTROL TERMINATIO N 3 2e beet eno ceto eh Det rt aet re eei aes 29 19 CONTROLDPEZEIMEBSEEBP diete tee ettet e eee tre ere eere ee dep redes 2
211. RUS to be labeled there as effective plastic strain EQ 1 hardening parameter k EQ 2 cap axis intercept X EQ 3 volumetric plastic strain eb EQ 4 first stress invarient Jj EQ 5 second stress invarient 72 EQ 6 not used EQ 7 not used EQ 8 response mode number EQ 9 number of iterations Formulation flag EQ 1 soil or concrete Cap surface may contract EQ 2 rock Cap doesn t contract Vectorization flag EQ 0 vectorized fixed number of iterations EQ 1 fully iterative If the vectorized solution is chosen the stresses might be slightly off the yield surface however on vector computers a much more efficient solution is achieved Tension Cut Off TOFF 0 positive in compression LS DYNA3D Version 936 MAT The implementation of an extended two invariant cap model suggested by Stojko 1990 is based on the formulations of Simo et al 1988 1990 and Sandler and Rubin 1979 In this model the two invariant cap theory is extended to include nonlinear kinematic hardening as suggested by Isenberg Vaughn and Sandler 1978 A brief discussion of the extended cap model and its parameters is given below Figure 19 6 yield surface of the two invariant cap model in pressure J J5p space Surface f4 is the failure envelope f is the cap surface and is the tension cutoff The cap model is formulated in terms of the invariants of the stress tens
212. Report 1082 LS DYNA3D USER S MANUAL Nonlinear Dynamic Analysis of Structures in Three Dimensions August 1 1995 Version 936 copyright 1992 1995 all rights reserved LIVERMORE SOFTWARE TECHNOLOGY CORPORATION Mailing Address Livermore Software Technology Corporation 2876 Waverley Way Livermore Ca 94550 FAX 510 449 2507 TEL 510 449 2500 Copyright 1995 LSTC All rights reserved TABLE OF CONTENTS TABLE OF CONTENTS PAALA M T T Dl A A E E O E I 1 iyu UO M L3 CHRONOLOGICAL HISTORY i e t e re te e E Rh beo ee RR o L3 DESCRIPTION OF L8 MATERIAE MODELS ree eter epe es atii d oae repa 1 20 SPATIAL DISCREJTIZATION 5 n sited pint ght digas oid PER ee he 1 22 SLIDING INTERFACES hior tione titer tie teen eite rb erit E AE EE EA E EEA EES 1 25 INTERFACE DEFINITIONS FOR COMPONENT ANALYSIS eee L27 CAPACITY iiie e eue egre ler ee eee e I 29 CODE ORGANIZATION inier epe don hU hier 1 30 SENSE SWITCH CONTROLS 2 ttr e Ente eto Rer e Feb een e ESSE RR ERE Ee o L31 PRECISION tet re bee 1 32 EXECUTION SYNTAX nOD epit d p Ro e p PE I 33 RESTART ANALYSIS neige dee ROGO ERE 1 37 VDA IGES DATABASES ka ext 1 39 MESH GEN
213. S HOURGLASS CONTROL CONTACT CONTACT Option RIGIDWALL Option LS DYNA3D Version 936 INTRODUCTION Table I 1 continued Keywords for the most commonly used options Boundary Conditions amp Loadings Constraints and spot welds Output Control Termination Restraints Gravity body load Point load Pressure load Thermal load Load curves Constrained nodes Welds 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 LS DYNA3D Version 936 NODE 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 Option DATABASE HISTORY Option DATABASE NODAL FORCE GROUP CONTROL TERMINATION CONTROL TERMINATION CONTROL CPU TERMINATION NODE 1 19 INTRODUCTION INTRODUCTION MATERIAL MODELS Some of the material models presently implemented are e elastic e orthotropic elastic e kinematic isotropic plasticity Krieg and Key 1976 e thermoelastoplastic Hallquist 1979 e soil and crushable non crushable foam Key 1974 e linear viscoelastic Key 1974 Blatz Ko rubber
214. S DYNA3D The interactive graphics are available by using the SW5 command after invoking the Ctrl C interrupt The MENU command brings up a push button menu ANIMATE BACK BGC BIP CENTER CL CMA COLOR CONTOUR COOR COP CR CUT LS DYNA3D Version 936 Animate saved sequence stop with switch 1 Return to previous display size after zoom then list display attributes Change display background color RGB proportions BGC red green blue Select beam integration point for contour BIP lt gt Center model center on node or center with mouse i e center cent value or cent gin Classification labels on display class commercial in confidence Color materials on limited color displays Set or unset shaded coloring of materials View with colored contour lines contour component gt list mat gt see TAURUS manual Get node information with mouse Hardcopy of display on the PC copy laserj paintj tekcol coljet or epson Restores cutting plane to default position Cut away model outside of zoom window use mouse to set zoom window size 1 Appendix G CX CY CZ DIF DISTANCE DMATERIALS DRAW DSCALE DYN ELPLT END ESCAPE EXECUTE FCL FOV FRINGE GETFRAME G 2 Rotate slice plane at zmin about x axis Rotate slice plane at zmin about y axis Rotate slice plane at zmin about z axis Change diffused light level for materia
215. S DYNA3D Version 936 11 1 ELEMENT ELEMENT ELEMENT BEAM OPTION Available options include BLANK THICKNESS Purpose Define beam and truss elements For beams two alternatives are available Standard is the stress resultant beam Belytschko beam using the BLANK option Using the THICKNESS option an integration through the thickness is performed for the so called Hughes Liu beam and the Belytschko Schwer beams Also so called discrete beams are defined with this option Card Format 1018 Variable Type idi Paid DA Vidi ii Pit i Optional Card Required if THICKNESS is specified after the keyword 11 2 ELEMENT LS DYNA3D Version 936 ELEMENT VARIABLE DESCRIPTION EID Element ID A unique number has to be specified PID Part ID see PART N1 Nodal point end 1 N2 Nodal point end 2 N3 Nodal point 3 THICIS Beam thickness in s direction at node 1 for integrated beam THIC2S Beam thickness in s direction at node 2 for integrated beam THICIT Beam thickness in t direction at node 1 for integrated beam THIC2T Beam thickness in t direction at node 2 for integrated beam A Area for resultant beam ISS Inertia about s axis for resultant beam ITT Inertia about t axis for resultant beam IRR Inertia about r axis for resultant beam SA Shear area for resultant beam Remarks 1 A plane through defines the orientation of the principal r s plane of the beam see Figure 11 1
216. S DYNA3D Version 936 12 17 EOS EOS pressure The bulk unloading modulus is a function of volumetic strain Volumetric strain 5 e H tension cutoff Figure 12 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 12 18 EOS LS DYNA3D Version 936 EOS EOS TABULATED This is Equation of state Form 9 Card Format Card 1 1 2 Card Format 5E16 0 3 Card 2 1 2 3 4 5 Card 3 Repeat Cards 2 and 3 for and 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 LS DYNA3D Version 936 12 19 EOS EOS VARIABLE DESCRIPTION GAMA y Initial internal energy VO Initial relative volume The tabulated equation of state model is linear in internal energy Pressure is defined by P C y y T ey E The volumetric strain y 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 DYNA3D will extrapolate to find the pressure if necessary 12 20 EOS LS DYNA3D Version 936 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 6 7 8 2 3 4 5
217. SCRIPTION PID Part ID of the part which is switched to a deformable material LS DYNA3D Version 936 29 3 RESTART RESTART STRESS INITIALIZATION OPTION This keyword allows a full deck restart to be performed in LS DYNA3D 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 keyword are BLANK DISCRETE SEATBELTS 29 32 RESTART LS DYNA3D Version 936 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 Default 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 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 SEATBBELT are defined LS DYNA3D Version 936 29 33 RESTART RESTART STRESS INITIALIZATION DISCRETE
218. STER SEGMENT NUMBER XCM 4 X COORDINATES MASTER SURFACE PROJECTED 4 Y COORDINATES MASTER SURFACE PROJECTED 2 4 Z COORDINATES MASTER SURFACE PROJECTED 5 5 SLAVE NODE PENALTY STIFFNESS 5 5 MASTER SEGMENT PENALTY STIFFNESS FORCEN NORMAL FORCE RVX RVY RVZ RELATIVE X Y Z VELOCITY BETWEEN SLAVE NODE AND MASTER SEGMENT LS DYNA3D Version 936 E 1 Appendix E Qe ke ee he e he e e e e he e he e he k e k se k k he k e k se k k he k e k e k k he k e e k k k ke k he e k k THE FOLLOWING VALUES ARE TO BE SET BY USER FRIC1 STATIC FRICTION COEFFICIENT FRIC2 DYNAMIC FRICTION COEFFICIENT FRIC3 DECAY CONSTANT FRIC4 VISCOUS FRICTION COEFFICIENT SETTING FRIC4 0 TURNS THIS OPTION OFF C K ke k He ke ke ke k ke ke ke ke k ke k k k k de k k k k k k k k k k k k k k k k kk k c c NINPUT NUMBER OF VARIABLES INPUT INTO UA c UA USERS ARRAY FIRST NINPUT LOCATIONS DEFINED BY USER THE LENGTH OF THIS ARRAY IS DEFINED ON CONTROL CARD 15 THIS ARRAY IS UNIQUE TO INTERFACE NSI SIDE MASTER FOR FIRST PASS THE MASTER e SURFACE IS THE SURFACE DESIGNATED IN THE INPUT SLAVE FOR SECOND PASS AFTER SLAVE AND MASTER SURFACES HAVE BE SWITCHED FOR THE 3 SYMMETRIC INTERFACE TREATMENT Qe e e e e he k k k k k k k k k e e k k k k k k k k k k k c RETURN END E 2 LS DYNA3D Version 936 App
219. SURFACE NODES TO SURFACE 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 TIEBREAK NODES TO SURFACE TIEBREAK SURFACE TO SURFACE TIED NODES TO SURFACE TIED SHELL EDGE TO SURFACE TIED SURFACE TO SURFACE LS DYNA3D Version 936 5 1 CONTACT CONTACT OPTION specifies a thermal contact and takes the single option THERMAL 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 DYNA3D but are included for extension in the near future The title card is picked up by some of the peripheral LS DYNA3D codes to aid in post processing 5 2 CONTACT LS DYNA3D Version 936 CONTACT The keyword options for the contact type and the corresponding Version 92X type numbers are STRUCTURED INPUT TYPE ID KEYWORD NAME al3 a5 210 13 3 18 17 23 16 14 15 10 20 21 19 22 pl N A 9 wo LS DYNA3D Version 936 AIRBAG SINGLE SURFACE AUTOMATIC NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE CONSTRAINT NODES TO SURFACE CONSTRAINT SURFACE TO SURFACE DRAWBEAD ERODING NODES TO SURFA
220. Second Card if SBSTYP 3 1 2 3 Variable Type Default Second Card if SBSTYP 4 1 2 3 Variable NID1 NID2 Type Default Remarks 11 18 ELEMENT LS DYNA3D Version 936 VARIABLE SBSID SBSTYP SBSFL NID DOF ACC ATIME SBRID PULRAT PULTIM TIME NIDI NID2 DMX DMN Remarks 1 2 ELEMENT DESCRIPTION Sensor ID see remark below Sensor type EQ 1 acceleration of node EQ 2 retractor pull out rate EQ 3 time EQ 4 distance between nodes Sensor flag EQ 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 y 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 1 ID Node 2 ID Maximum distance Minimum distance Sensor ID s should start at 1 and be consecutive Node should not be on rigid body velocity boundary condition or other Oimposed motion feature Sensor triggers when the distance between the two nodes is d gt dmax or d lt dmin LS DYNA3D Version 936 11 19 ELEMENT ELEMENT Sensors are used to trigger locking of retractors and activate pretensioners Four types of sensors are available which trigger according to the f
221. Sn Ss where fy and f are the normal and shear interface force Component fn contributes for tensile values only When the failure time tr is reached the nodal rigid body becomes inactive and the constrained nodes may move freely In Figure 4 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 to nodes 2 and n 1 Progressive failure is necessary to preclude failures that would create new rigid bodies Ductile fillet weld failure due to plastic straining is treated identically to spotweld failure Brittle failure of the fillet welds occurs when Blo 322 r gt where On normal stress Tn Shear stress in direction of weld local y tt Shear stress normal to weld local x of failure stress p failure parameter Component On 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 In Figure 4 2 the ordering of the nodes is shown for the 2 node and 3 node fillet welds This order is with respect to LS DYNA3D Version 936 4 5
222. T 3 NUMNP NODAL TRANSLATIONAL VELOCITY VECTOR XI 3 NUMNP INITIAL COORDINATES 0 UT 3 NUMNP NODAL TRANSLATIONAL DISPLACEMENT VECTOR IDRINT FLAG FOR DYNAMIC RELAXATION PHASE NE 0 DYNAMIC RELAXATION IN PROGRESS EQ 0 SOLUTION PHASE NUMNP NUMBER OF NODAL POINTS DT2 TIME STEP SIZE N 1 2 NUMBER OF VARIABLES INPUT INTO UA UA USER S ARRAY FIRST NINPUT LOCATIONS DEFINED BY USER THE LENGTH THIS ARRAY IS DEFINED ON CONTROL CARD 10 THIS ARRAY IS UNIQUE INTERFACE NSI SET FLAG FOR ACTIVE CONTACT D 1 Appendix D e ISKIP 0 ACTIVE ISKIP 1 INACTIVE e Qe ke e e he e e e e e e he e he e he k e e e k k ke k e k k k k ke k e e k k k ke k k k e ke k k k DIMENSION MSR NSV THMR THSV VT 3 XI 3 UT 3 UA c THE FOLLOWING SAMPLE OF CODEING IS PROVIDED TO ILLUSTRATE HOW THIS SUBROUTINE MIGHT USED HERE WE CHECK TO SEE IF THE SURFACES IN THE SURFACE SURFACE CONTACT ARE SEPARATED IF SO THE ISKIP 1 AND THE CONTACT TREATMENT IS SKIPPED e IF NTY EQ 4 RETURN DT2HLF DT2 2 XMINS 1 E20 XMAXS XMINS YMINS 1 E20 YMAXS YMINS ZMINS 1 E20 ZMAXS ZMINS XMINM 1 E20 XMAXM XMINM YMINM 1 E20 YMAXM YMINM ZMINM 1 E20 ZMAXM ZMINM THKS 0 0 THKM 0 0 DO 10 I 1 NSN DSP1 UT 1 NSV I DT2HLF VT 1 NSV I DSP2 UT 2 NSV I DT2HLF VT 2 NSV I DSP3 UT 3 NSV I DT2
223. T RIGID NODES RIGID BODY CONTACT_RIGID_BODY_ONE_WAY_TO_RIGID_BODY CONTACT_RIGID_BODY_TWO_WAY_TO_RIGID_BODY CONTACT SINGLE EDGE CONTACT_SLIDING_ONLY LS DYNA3D Version 936 1 47 INTRODUCTION INTRODUCTION CONTACT_SLIDING_ONLY_PENALTY CONTACT_TIEBREAK_NODES_TO_SURFACE CONTACT_TIEBREAK_SURFACE_TO_SURFACE CONTACT_TIED_SHELL_EDGE_TO_SURFACE CONTACT ID DATABASE AVS DATABASE MOVIE DATABASE_MPGS DATABASE BEAM SET DATABASE SOLID SOLID SET DATABASE TSHELL TSHELL SET e DATABASE_NODAL_FORCE_GROUP DATABASE_TRACER DEFORMABLE_TO_RIGID ELEMENT_SEATBELT_ACCELEROMETER INTERFACE_COMPONENT INTERFACE JOY LOAD_SUPERPLASTIC_OPTION USER PART REPOSITION RIGIDWALL_PLANAR_FORCES TERMINATION MPP LS DYNA3D can restart however the restart options are still quite limited Only the termination time plot interval time step control and restart dump frequency may be changed when restarting The supported keywords are CONTROL_TERMINATION CONTROL TIMESTEP DATABASE BINARY Arbitrary Numbering MPP LS DYNA3D assumes arbitrarily numbered input This affects the format of some of the input options For example if the initial velocity option is used all nodes in the problem must appear in the initial velocity section L48 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION Contact Interfaces MPP LS DYNA3D u
224. TABASE BINARY OPTION Card Format Variable Default 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 LS DYNA3D Version 936 8 17 DATABASE 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 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 8 18 DATABASE LS DYNA3D Version 936 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 39 DTOUT Output time interval for output to pressure curvel and curve files The pressure file contains general information from the analysis and the files curvel and curve 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 LS DYNA3D Version 936 8
225. TD LC This is thermal material property type 10 It allows isotropic thermal properties that are temperature dependent specified by load curves to be defined The properties must be defined for the tempertaure range that the material will see in the analysis Card Format 1 of 2 1 2 3 4 5 6 7 8 Card Format 2 of 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be chosen TRO Thermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number see DEFINE_CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT Ip function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation HCLC Load curve ID specifying heat capacity vs temperature TCLC Load curve ID specifying thermal conductivity vs temperature 19 242 MAT LS DYNA3D Version 936 NODE 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 0 218 Card 1 1 2 3 4 5 6 7 8 9 10 Variable Type Default VARIABLE DESCRIPTION NID Node number X X coordinate Y y coordinate Z Z coordinate TC Translational Constraint EQ 0 no constraints EQ 1 constrained x displacement EQ 2 c
226. THERMAL NONLINEAR 6 26 CONTROL THERMAL SOLNVER nente ete rettet teet 6 27 CONTROL THERMAL TIMESTEP 52 three P rtp eee dept 6 29 CONTROL TIMES TEP sitive alban ain An E e eb dettes 6 30 DAMBPING 7 1 DAMPING GEOBAL trem o o re e ted eoo qp eve e ere 7 1 DAMBING PART MASS eter tete eite tt feto eite tee ferens 7 3 DAMPING PART STIFENESS n breit baee dives 7 4 DATABASE resser sipaki rs soati ria ate ES a ENE SAPA 8 1 DATABASE OPTION a RI eh HB E EIAS 8 2 DATABASE BINARY OPTION np rtr ie teo e eue Rp oae Feo eo de dos 8 4 DATABASE CROSS SECTION OPTION 244 20222 2 0 00 0 000 8 6 DATABASE EXTENT OPTION bt a ee aep 8 9 DATABASE HISTORY OPTION uc nte RESET 8 16 DATABASE NODAL FORCE 8 17 DATABASE SPRING 8 18 DATABASE SUPERPLASTIC 8 19 SDATABASE TRACER estne RB IR eR bt nei 8 20 rn 9 1 DBPEINE BOX 9 2 DEFINE COORDINATE NOD
227. TION MID Material ID A unique number has to be chosen DC Damping constant force displacement rate or moment roation rate 19 218 MAT LS DYNA3D Version 936 MAT MAT SPRING ELASTOPLASTIC This material allows to simulate an elastoplastic translational or rotational spring with isotropic hardening located between two nodes Only one degree of freedom is then connected Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material number A unique number has to be chosen K Elastic stiffness force displacement or moment rotation KT Tangent stiffness force displacement or moment rotation FY Yield force or moment LS DYNA3D Version 936 19 219 MAT MAT MAT SPRING NONLINEAR ELASTIC This material allows to simulate a nonlinear elastic translational or rotational spring with arbitrary force displacement resp moment rotation dependency Optionally strain rate effects can be considered through a velocity dependent scale factor With the spring located between two nodes only one degree of freedom is connected Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIPTION MID Material number A unique numbe has to be chosen LCD Load curve ID describing force versus displacement or moment versus rotation relationship LCR Optional loadcurve describing scale factor on force or moment as a function of relative velocity resp rotational velocity 19 220 MAT LS DYNA3D Version
228. TO PROGRAMS CAL3D AND MAID VIMO EE F 1 INTRODUCTION cet tot si save tee ee vost ede e eee eres F 1 THE LS DYNA3D OCCUPANT SIMULATION PROGRAM 2222222 21 F 1 DUMMY MODELING teet p IRURE F 4 AIRBAG MODELING eti t reso ERE Ee dave eves Bus DL evo Fe Tee 4 KNEE BOLSTER 6 COMMON ERRORS sis utes One e en i obtenir F 6 APPENDIX G INTERACTIVE GRAPHICS G 1 APPENDIX H INTERACTIVE MATERIAL MODEL DRIVER eene H 1 INTRODUCTION soca te e Widnes ren e e aureus ede H 1 INPUT DEFINITION Ain Anas Ava anti Aarti i eee dental H 1 INTERACTIVE DRIVER 8 2 3 APPENDIX I MDADXATABASE 1 1 x LS DYNA3D Version 936 TABLE OF CONTENTS APPENDIX J LS TAURUS USER S MANUAL bonnet tbid ates J 1 To open the LS TAURUS User s Manual select LS TAURUS in the Bookmark List which should be located at the left hand side of this window LS DYNA3D Version 936 xi INTRODUCTION LS DYNA3D USER S MANUAL Nonlinear Dynamic Analysis of Structures in Three Dimensions ABSTRACT This manual provides a description of the input data required by Version 93X of LS DYNA3D A new keyword database provides a more flexib
229. U must be set to zero The other is to define a mass flow out by a load curve then and have to both be set to zero 1 6 AIRBAG LS DYNA3D Version 936 AIRBAG Additional card required for ADIABATIC GAS MODEL option 1 2 3 4 5 6 7 8 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 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 po 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 p y I pe 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 LS DYNA3D Version 936 1 7 AIRBAG AIRBAG The pressure above is the absolute pressure the resultant pressure acting on the control volume is PSF p p where PSF is the pressure scale factor Starting from the initial pressure p an initial internal energy is calculated _ Pot De 70 p y 1 Additional 4 cards are requ
230. VC A on see above 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 LS DYNA3D Version 936 VARIABLE LCIDRF LCIDNF DBDTH DFSCL NUMINT ISYM EROSOP IADJ NFLF SFLF LS DYNA3D Version 936 CONTACT DESCRIPTION Load curve ID giving the bending component of the restraining force F bending per unit draw bead length as a function of displacement see Figure 5 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 Load curve ID giving the normal force per unit draw bead length as a function of displacement 6 see Figure 5 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 Draw bead depth see Figure 5 2 Necessary to determine correct displacement from contact displacements Scale factor for load
231. Version 936 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 Default VARIABLE DESCRIPTION PIDM Master rigid body part ID see PART PIDS Slave rigid body part ID see PART All actions valid for the master rigid body e g constraints given velocity are now also valid for the newly created rigid body LS DYNA3D Version 936 4 31 CONSTRAINED 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 load 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 4 9 Card Format Card 1 1 2 3 4 5 6 7 8 PID LCMAX LCMIN PSIDMX PSIDMN LCVMNX DIR Card 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 See DEFINE_CURVE EQ 0 no limitation of the maximum displacement LCMIN Load curve ID defining the minimum coordinate as a function of time See DEFINE_CURVE EQ 0 no limitation of the minimum displacement 4 32 CONSTRAINED LS DYNA3D Vers
232. XL X coordinate of point on local x axis YL 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 YP Y coordinate of point in local x y 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 DYNA3D Version 936 9 5 DEFINE DEFINE DEFINE COORDINATE VECTOR Purpose Define a local coordinate system with two vectors see Figure 9 2 From the cross product xy X x z the z axis is determined followed by the computation of the y axis by y z X x Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION CID Coordinate system ID A unique number has to be defined XX 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 0 Figure 9 2 Definition of the coordinate system with two vectors 9 6 DEFINE LS DYNA3D Version 936 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 LCID SIDR SFA SFO OFFA OFFO DATTYP me
233. Y IF NDOF 6 IRBODY FLAG FOR RIGID BODY NODAL POINTS IF DEFORMABLE NODE THEN SET TO 1 0 IF RIGID BODY NODE THEN SET TO 0 0 DEFINED IF AN ONLY IF RIGID BODY ARE PRESENT QQQ0Q000000000000000000000000000000nn02n0n LS DYNA3D Version 936 1 Appendix C NE 0 DYNAMIC RELAXATION IN PROGRESS EQ 0 SOLUTION PHASE I E IRBODY NE O IF NO RIGID BODY ARE PRESENT USRHV LENHV USER DEFINED HISTORY VARIABLES THAT ARE STORED IN THE RESTART FILE LENHV 100 U NUMMAT WHERE NUMMAT IS THE OF MATERIALS THE PROBLEM ARRAY USRHV IS UPDATED ONLY THIS SUBROUTINE 55 FOR DYNA3D WHICH MAY BE SET SW1 LS DYNA3D TERMINATES WITH RESTART FILE SW3 LS DYNA3D WRITES RESTART FILE SW4 LS DYNA3D WRITES PLOT STATE TOTALM TOTAL MASS IN PROBLEM CYCLE CYCLE NUMBER IDRINT FLAG FOR DYNAMIC RELAXATION PHASE COMMON PTIMES PRTIMS 32 PRTLST 32 IGMPRT PRTIMS 32 OUTPUT INTERVALS FOR ASCII FILES ASCII FILES 1 CROSS SECTION FORCES 2 RIGID WALL FORCES 3 DATA 4 ELEMENT DATA 5 GLOBAL DATA 6 DISCRETE ELEMENTS 7 MATERIAL ENERGIES 8 NODAL INTERFACE FORCES 9 RESULTANT INTERFACE FORCES 10 SMUG ANIMATOR 11 SPC REACTION FORCES 12 NODAL CONSTRAIN RESULTANT FORCES 13 AIRBAG STATISTICS 14 AVS DATABASE 15 NODAL FORCE GROUPS 16 OUTPUT INTERVALS FOR NODAL BOUNDARY CONDITIONS 17 32 UNUSED AT THIS TIME
234. a single surface contact algorithm to eliminate interpenetrations during the inflation phase see CONTACT OPTION The contact types showing an a in front are most suited for airbag analysis Current recommended material types for the airbags are MAT ELASTIC Type 1 Elastic MAT COMPOSITE DAMAGE Type 22 Layered orthotropic elastic for composites MAT FABRIC Type 34 Fabric model for folded airbags FA LS DYNA3D Version 936 Appendix F Model 34 is a fabric model which can be used for flat bags As a user option this model may or may not support compression The elements which can be used are as follows Belytschko Tsay quadrilateral with 1 point quadrature This element behaves rather well for folded and unfolded cases with only a small tendency to hourglass The element tends to be a little stiff Stiffness form hourglass control is recommended Belytschko Tsay membrane This model is softer than the normal Belytschko Tsay element and can hourglass quite badly Stiffness form hourglass is recommended As a better option the fully integrated Belytschko Tsay membrane element can be chosen CO Triangular element The CO triangle is very good for flat bag inflation and has no tendency to hourglass The best choice is a specially developed airbag membrane element with quadrilateral shape This is an automatic choice when the fabric material is used As an airbag inflates a considerable amount of energy is tr
235. ace shell edge tied to shell surface nodes spot welded to surface tiebreak interface one way treatment of sliding impact friction 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 LS DYNA3D Version 936 1 25 INTRODUCTION INTRODUCTION 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 abov
236. ailable for the D3PLOT D3THDT and INTFOR files NOBEAM Option flag for DATABASE_ BINARY D3PLOT If set to 1 the spring and damper discrete elements are not added to the D3PLOT database where they are displayed as beam elements This option is useful when translating old LS DYNA3D 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 causing a fatal error NPLTC DT ENDTIME NPLTC applies to D3PLOT only This overrides the DT specified in the first field LS DYNA3D Version 936 8 5 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 8 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 5 6 7 8 mI IEIIIIIL Format 2 of 2 for the PLANE option 1 2 3 4 5 6 7 8 8 6 DATABASE LS DYNA3D Version 936 DATABASE Resultants are computed on this plane Origin of cutting plane Figure 8 1 Definition of cutting plane for automatic definiti
237. ailed material symf p a1f a2 p 19 48 MAT LS DYNA3D Version 936 MAT MAT ORIENTED CRACK This is Material Type 17 This material may be used to model brittle materials which fail due to large tensile stresses Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type Default VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic hardening modulus FS Fracture stress PRF Failure or cutoff pressure lt 0 0 When the maximum principal stress exceeds the fracture stress the element fails on a plane perpendicular to the direction of the maximum principal stress In tension the element will not carry any stresses on the fracture plane but in compression it will carry both normal and shear stresses If the fracture stress is exceeded in another direction the element fails isotropically the element loses its ability to carry tension the deviatoric stresses are set to zero and the material behaves as a fluid LS DYNA3D Version 936 19 49 MAT MAT MAT POWER LAW PLASTICITY This is Material Type 18 This is an isotropic plasticity model with rate effects which uses a power law hardening rule Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s r
238. al Type 60 which was developed to simulate forming of glass products e g car windshields at high temperatures Deformation is by viscous flow but elastic deformations can also be large The material model in which the viscosity may vary with temperature is suitable for treating a wide range of viscous flow problems and is implemented for brick and shell elements Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 Card 4 19 150 MAT LS DYNA3D Version 936 Card 5 Card 6 MAT ALPHA ALPHA2 ALPHA3 ALPHA4 5 ALPHA7 ALPHA8 VARIABLE MID RO VO A B C LCID T2 TN PR2 PRN V1 V2 VN El E2 EN ALPHA LS DYNA3D Version 936 DESCRIPTION Material identification A unique number has to be chosen Mass density Temperature independent viscosity coefficient Vo If defined the temperature dependent viscosity defined below is skipped see type 1 and ii definitions for viscosity below Viscosity coefficient see type 1 and ii definitions for viscosity below Viscosity coefficient see type 1 and ii definitions for viscosity below Viscosity coefficient see type 1 and ii definitions for viscosity below Load curve see DEFINE CURVE defining factor on viscosity versus time Optional Temperatures define up to 8 values Poisson s ratios for the temperatures Corresponding viscosity coeffic
239. al input if they are needed in a later restart Unless these properties are defined LS DYNA3D 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 1 2 3 4 5 6 7 8 Variable Default Card 2 1 2 3 4 5 6 7 8 Type Card 3 1 2 3 4 5 6 7 8 Variable Default LS DYNA3D Version 936 10 7 DEFORMABLE TO RIGID DEFORMABLE TO RIGID VARIABLE PID XC YC ZC TM IXX IXY IXZ IYY 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 Ixx xx component of inertia tensor 10 8 DEFORMABLE TO RIGID LS DYNA3D Version 936 ELEMENT ELEMENT The element cards in this section are defined in alphabetical order ELEMENT BEAM OPTION ELEMENT DISCRETE 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 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 a keyword control card L
240. alent 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 46 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION MPP LS DYNA3D USER INFORMATION Supported Features First and foremost the only input formats currently supported are 920 930 and keyword Models in any of the older formats will need to be converted to one these input formats before then can be run with the current version of LS DYNA3D for massively parallel processors mpp The large majority of LS DYNA3D options are available on the MPP computers Those that are not supported are being systematically added Unless otherwise noted here all options of LS DYNA3D version 93x are supported by MPP LS DYNA3D Here is the list of unsupported options ALE BOUNDARY_CONVECTION BOUNDARY_CYCLIC BOUNDARY_FLUX BOUNDARY_RADIATION BOUNDARY_TEMPERATURE BOUNDARY_USA_SURFACE CONSTRAINED_RIGID_BODY_STOPPERS CONSTRAINED_SHELL_TO_SOLID CONSTRAINED TIE BREAK CONSTRAINED TIED NODES FAILURE CONTROL ADAPTIVE CONTACT_AIRBAG_SINGLE_SURFACE CONTACT_CONSTRAINT_NODES_TO_SURFACE CONTACT_CONSTRAINT_SURFACE_TO_SURFACE CONTACT_DRAWBEAD CONTACT ERODING NODES TO SURFACE CONTACT_ERODING_SINGLE_SURFACE CONTACT_ERODING_SURFACE_TO_SURFACE CONTAC
241. alize 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 1 2 3 4 5 6 7 8 Variable Default Define NTPS cards below one per integration point 2 1 2 3 4 5 6 7 8 SIGI1 SIG22 51633 SIG12 SIG23 SIG31 EPS 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 LS DYNA3D Version 936 15 5 INITIAL INITIAL VARIABLE DESCRIPTION NPTS Number of integration points output SIGIJ Define the IJ stress component EPS Effective plastic strain 15 6 INITIAL LS DYNA3D Version 936 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 4 5 6 7 8 TE Define NPLANE X NTHICK cards below one per integration point For each through thickness point define NPLANE points NPLANE sh
242. alysis 8 2 DATABASE LS DYNA3D Version 936 DATABASE Card Format Default VARIABLE DESCRIPTION DT Time interval between outputs If DT is zero no output is printed FLAGI Meaning depends on the file being written see below The flags on the above card have the following meanings RBDOUT FLAGI Default option for writing to RBDOUT file EQ 0 print rigid body data into file default EQ n do not print rigid body data into file Remark 1 This keyword is also used in the restart phase see RESTART Thus the output interval can be changed when restarting 2 All information in the files except in AVSFLT MOVIE AND MPGS can also be plotted using the post processor LS TAURUS Arbitrary cross plotting of results between ASCII files is easily handled LS DYNA3D Version 936 8 3 DATABASE DATABASE DATABASE BINARY OPTION Options for binary output files with the default names given include D3PLOT Dt for complete output states See also DATABASE EXTENT BINARY D3THDT Dt for time history data of element subsets See DATABASE HISTORY D3DRLF Dynamic relaxation database Define output frequency in cycles D3DUMP Binary output restart files Define output frequency in cycles RUNRSF Binary output restart file Define output frequency in cycles INTFOR Dt for output of contact interface data file name must be given XTFILE Flag to specify output of extra time history data to XTFILE at same time as D3THDT f
243. an FMNGR the 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 LS DYNA3D Version 936 12 25 EOS EOS EOS TENSOR PORE COLLAPSE This is Equation of state Form 11 Card Format Card 1 1 2 3 4 5 6 7 8 EOSID NLD NCR MUI MU2 Type 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 The pore collapse model described in
244. an be constant with respect to the plastic strain The case of no strain hardening can be obtained by setting the exponent of the plastic strain equal to a very small positive value i e 0 0001 LS DYNA3D Version 936 19 161 MAT MAT MAT MODIFIED ZERILLI ARMSTRONG This is Material Type 65 which is a rate and temperature sensitive plasticity model which is sometimes preferred in ordnance design calculations 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 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear Modulus EO 0 initial strain N n exponent for Bcc metal TROOM Room temperature 19 162 MAT LS DYNA3D Version 936 VARIABLE PC SPALL Cl C2 C3 C4 C5 C6 EFAIL Bl B2 B3 Gl G2 G3 G4 MAT DESCRIPTION Pressure cutoff pc Spall Type EQ 1 0 minimum pressure limit EQ 2 0 maximum principal stress EQ 3 0 minimum pressure cutoff C1 coefficients for flow stress see notes below C2 coefficients for flow stress see notes below C3 coefficients for flow stress see notes below C4 coefficients for flow stress see notes below C5 coefficients for flow stress see notes below C6 coefficients for flow stress see notes below Failure strain for erosion B1 coefficients for polynomial to represent temperature dependency of flow stress yield B2 B3
245. an be overridden on these cards otherwise A1 DA1 etc 24 10 SET LS DYNA3D Version 936 SET SET SHELL OPTION Available options include LIST COLUMN Purpose Define a set of shell elements with optional identical or unique attributes Card Format Variable Default EIDI EID2 EID3 EID4 EID5 EID6 EID7 EID8 Remarks LS DYNA3D Version 936 24 11 SET SET Card 2 3 4 OPTION COLUMN The next card terminates the input 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 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 24 12 SET LS DYNA3D Version 936 SET Remarks 1 Shell attributes can 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 DA1 FSF Coulomb friction scale factor DA2 VSF Viscous friction scale factor 2 The default
246. anced 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 with limited capabilities Built in least squares fit for rubber model constitutive constants Large hystersis in hyperelastic foam Bilhku Dubois foam model Generalized rubber model and many more enhancements not mentioned above In the sections that follow some aspects of the current version of LS DYNA3D are briefly discussed LS DYNA3D Version 936 L7 INTRODUCTION INTRODUCTION DESCRIPTION OF KEYWORD INPUT The new keyword input database in Version 93X provides a more flexible and logically organized database that will hopefully reduce the time required by new users in understanding the input Similar functions are grouped together under the same keyword For example under the keyword ELEMENT we not only include solid beam and shell elements but also spring elements discrete dampers seat belts and lumped masses
247. ansferred to the surrounding air This energy transfer decreases the kinetic energy of the bag as it inflates In the control volume logic this is simulated either by using either a mass weighted damping option or a back pressure on the bag based on a stagnation pressure In both cases the energy that is absorbed is a function of the fabric velocity relative to a rigid body velocity for the bag For the mass weighted case the damping force on a node is proportional to the mass times the damping factor times the velocity vector This is quite effective in maintaining a stable system but has little physical justification The latter approach using the stagnation pressure method estimates the pressure needed to accelerate the surrounding air to the speed of the fabric The formula for this is Areax ox V Vog J This formula accomplishes a similar function and has a physical justification Values of the damping factor are limited to the range of to 1 but a value of 0 1 or less is more likely to be a good value LS DYNA3D Version 936 F 5 Appendix F KNEE BOLSTER The knee to knee bolster interactions are characterized by the stiffness of the knee being comparable to that of the knee bolster Therefore modeling the knee as a rigid body may produce large errors in the interaction forces Calibrated force deflection curves could be determined but they would have no predictive value for slight changes to knee bolster des
248. ard Format Card 1 1 2 3 4 5 6 7 8 Variable Type Card 2 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density C Sound speed BETA Damping factor Recommend values are between 0 1 and 1 0 CF Cavitation flag EQ 0 0 off EQ 1 0 on ATMOS Atmospheric pressure optional GRAV Gravitational acceleration constant optional XP x coordinate of free surface point LS DYNA3D Version 936 19 215 MAT MAT VARIABLE XP YP XN YN ZN 19 216 MAT DESCRIPTION y coordinate of free surface point Z coordinate of free surface point x direction cosine of free surface normal vector y direction cosine of free surface normal vector z direction cosine of free surface normal vector LS DYNA3D Version 936 MAT MAT SPRING ELASTIC This allows to simulate a translational or rotational elastic spring located between two nodes Only one degree of freedom is then connected Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material ID A unique number has to be chosen K Elastic stiffness force displacement or moment rotation LS DYNA3D Version 936 19 217 MAT MAT MAT DAMPER VISCOUS This material allows to simulate a linear translational or rotational damper located between two nodes Only one degree of freedom is then connected Card Format Card 1 1 2 3 4 5 6 7 8 Variable Type VARIABLE DESCRIP
249. assumed to be dependent on the relative velocity vre of the surfaces in contact Dc4v Ho FD FS FD e Pra Coefficient for viscous friction This is necessary to limit the friction force to a maximum A limiting force is computed VC Acont being the area of the segment contacted by the node in contact The suggested value for is to use the yield stress in shear VC 2 where v3 O is the yield stress of the contacted material VDC 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 VDC Damping coefficient iso crit 88 VDC 20 Epi is determined in the following fashion by LS DYNA3D mass of master Cae 2mw m min Mstave UN resp slave node m m w k Slave master interface stiffness Mslave master LS DYNA3D Version 936 5 11 CONTACT CONTACT VARIABLE PENCHK BT DT SFS SFM SST MST SFST SFMT FSF VSF KPF 5 12 CONTACT DESCRIPTION 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 thickness is taken as the shell thickness if the segment belongs to a shell element or it is taken as 1 20 o
250. at Remarks Type 18 20 LOAD LS DYNA3D Version 936 LOAD VARIABLE DESCRIPTION LCPI Load curve number for Phase I pressure loading see DEFINE CURVE CSP1 Contact surface number to determine completion of Phase 1 NCPI Percent of nodes in contact to terminate Phase I see CONTACT OPTION LCP2 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 1 Optionally a second phase can be defined In this second phase a unique set of pressure segm
251. ate ZMX Zmax coordinate 9 2 DEFINE LS DYNA3D Version 936 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 computed from the cross product of x and y see Figure 9 1 x X y then the y axis is computed via y z X x Card Format 1 2 3 4 5 6 7 8 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 Remark 1 The nodes N1 N2 and N3 must be separated by a reasonable distance and not colinear to avoid numerical inaccuracies Figure 9 1 Definition of local coordinate system using three nodes LS DYNA3D Version 936 9 3 DEFINE DEFINE DEFINE COORDINATE SYSTEM Purpose Define a local coordinate system with three points The same procedure as described in Figure 9 1 see DEFINE COORDINATE NODES is used The coordinates of the nodes are given instead is defined by 70 is defined by XL YL ZL and by Card Format Remarks Variable Default Remarks 9 4 DEFINE LS DYNA3D Version 936 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
252. aterial parameter HR EQ 1 0 Tangent modulus HR EQ 2 0 k strength coefficient for exponential hardening P2 Material parameter HR EQ 1 0 Yield stress HR EQ 2 0 n exponent M m exponent in Barlat s yield surface ROO Roo Lankford parmeter determined from experiments R45 R45 Lankford parmeter determined from experiments R90 Rog Lankford parmeter determined from experiments AOPT Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE_COORDINATE_NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR 19 110 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector XP YP ZP Coordinates of point p for AOPT 1 1 2 Components of vector a for 2 V1 V2 V3 Components of vector v for AOPT 3 D1 D2 D3 Components of v
253. atio K Strength coefficient N Hardening exponent SRC Strain rate parameter C if zero rate effects are ignored SRP Strain rate parameter P if zero rate effects are ignored Elastoplastic behavior with isotropic hardening is provided by this model The yield stress Oy is a function of plastic strain and obeys the equation e is the elastic strain to yield and is the effective plastic strain logrithmic 19 50 MAT LS DYNA3D Version 936 MAT Strain rate is accounted for using the Cowper and Symonds model which scales the yield n I P stress with the factor where 6 is the strain rate LS DYNA3D Version 936 19 51 MAT MAT MAT STRAIN RATE DEPENDENT PLASTICITY This is Material Type 19 A strain rate dependent material can be defined For an alternative see Material Type 24 Required is a curve for the yield stress versus the effective strain rate Optionally Young s modulus and the tangent modulus can also be defined versus the effective strain rate Also optional failure of the material can be defined either by defining a von Mises stress at failure as a function of the effective strain rate valid for solids shells thick shells or by defining a minimum time step size only for shells Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio LCI Load curve ID
254. ation point Bg material angle at eigth integration point Bnip material angle at nipth integration point 23 11 SECTION SECTION SECTION SOLID OPTION Options include BLANK 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 SMOOTHING for the smoothing definition Cards 2 1 2 3 4 5 6 7 8 AFAC BFAC CFAC DFAC START END AAFAC 23 12 SECTION LS DYNA3D Version 936 VARIABLE SECID ELFORM AET AFAC BFAC CFAC DFAC START END AAFAC LS DYNA3D Version 936 SECTION DESCRIPTION Section ID SECID is referenced on the PART card and must be unique Element formulation options EQ 1 constant stress solid element default EQ 2 fully integrated S R solid EQ 3 fully integrated quadratic eight 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 Ambient Element type EQ 1 temperature EQ 2 pressure and temperature EQ 3 pressure outflow EQ 4 pressure inflow default Smoothing weight factor Simple average EQ 1 turn smoothing off Smoothing weight factor Volume weighting Smoothing weight factor Isoparametri
255. attributes are taken 3 The default shell attributes can be overridden on these cards otherwise 1 etc LS DYNA3D Version 936 24 13 SET SET SET SOLID Purpose Define a set of solid elements Card Format Variable Default Type VARIABLE DESCRIPTION SID Set ID All solid sets should have a unique set ID First element ID K2 Second element ID K8 Eighth element ID 24 14 SET LS DYNA3D Version 936 SET SET TSHELL Purpose Define a set of thick shell elements Card Format 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 LS DYNA3D Version 936 24 15 SET TERMINATION TERMINATION TERMINATION_OPTION 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 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 centre of mass displacement of the rigid body specified reaches either the maximum or minimum value stops 1 2 or 3 or the
256. aximum value The strain rate parameters C and P the curve ID LCSR EPS1 EPS8 and ES1 ES8 are ignored if a Table ID is defined LCSR Load curve ID defining strain rate scaling effect on yield stress 19 68 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION EPS1 EPS8 Effective plastic strain values optional if SIGY is defined At least 2 points should be defined ES 1 ES8 Corresponding yield stress values to EPS1 EPS8 The stress strain behavior may be treated by a bilinear stress strain curve by defining the tangent modulus ETAN Alternately a curve similar to that shown in Figure 19 4 is expected to be defined by EPS1 ES1 EPS8 ES8 however an effective stress versus effective plastic strain curve LCSS may be input instead if eight points are insufficient The cost is roughly the same for either approach The most general approach is to use the table definition LCSS discussed below Three options to account for strain rate effects are possible I Strain rate may be accounted for using the Cowper and Symonds model which scales the yield stress with the factor 1 where is the strain rate II For complete generality a load curve LCSR to scale the yield stress may be input instead In this curve the scale factor versus strain rate is defined III If different stress versus strain curves can be provided for various strain rates the option using the reference to a table LCSS
257. bbu Ecc Eccu B Eccu Gab Gabu B G Gabu Gbc B G Gea Geau PG Geau max min Ey 110 1 Vr and G is the elastic shear modulus for the fully compacted honeycomb material where E ECTS The relative volume V is defined as the ratio of the current volume to the initial volume Typically 1 at the beginning of a calculation The viscosity coefficient MU should be set to a small number usually 02 10 is okay Alternatively the two bulk viscosity coefficients on the control cards should be set to very small numbers to prevent the development of spurious pressures that may lead to undesirable and confusing results The latter is not recommended since spurious numerical noise may develop The load curves define the magnitude of the average stress as the material changes density relative volume see Figure 19 7 Each curve related to this model must have the same number of points and the same abscissa values There are two ways to define these curves a as a function of relative volume V or b as a function of volumetric strain defined as g y 1 V LS DYNA3D Version 936 19 81 MAT MAT In the former the first value in the curve should correspond to a value of relative volume slightly less than the fully compacted value In the latter the first value in the curve should be less than or equal to zero corresponding to tension and increase to full compaction
258. ble 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 connectivities for all elements which include shells beams solids thick shells springs dampers seat belts and concentrated masses in LS DYNA3D LS DYNA3D Version 936 1 13 INTRODUCTION INTRODUCTION 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 card or INITIAL_ VELOCITY cards In the case of INITIAL 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
259. blems it becomes an option to limit the size of the models LS DYNA3D Version 936 3 9 BOUNDARY BOUNDARY BOUNDARY PRESCRIBED MOTION OPTION Available options include NODE SET RIGID Purpose Define an imposed nodal motion velocity acceleration or displacement on a node or a set of nodes Also velocities and displacements can be imposed on rigid bodies Card Format Card 1 1 2 3 4 5 6 7 8 Default Card is required if DOF 9 10 11 on the first card If DOF lt 9 skip this card Card 2 1 2 3 4 5 6 7 8 Default 3 10 BOUNDARY LS DYNA3D Version 936 VARIABLE NID NSID PID DOF VAD LCID SF VID DEATH OFFSETI OFFSET2 BOUNDARY DESCRIPTION Node ID NID nodal set ID NSID SEE SET_NODE or part ID PID see PART for a rigid body 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 motion about the vector given by the VID Rotation about the normal axes is permitted
260. brittle failure of spotwelds M m exponent for shear force only for the brittle failure of spotwelds SIGY Of stress at failure for brittle failure BETA failure parameter for brittle failure L L length of fillet butt weld see Figure 4 2 and 4 3 W w width of flange see Figure 4 2 A a width of fillet weld see Figure 4 2 ALPHA a weld angle see Figure 4 2 in degrees D d thickness of butt weld see Figure 4 3 LT Lt transverse length of butt weld see Figure 4 3 4 4 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED Failures can include both the plastic and brittle failures These can be used either independently or together Failure occurs when either criteria is met Spotweld failure due to plastic straining occurs when the effective nodal plastic strain P exceeds the input value fai 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 in slightly increased run times Brittle failure of the spotwelds occurs when met T gt 1
261. c Smoothing weight factor Equipotential Start time for smoothing End time for smoothing ALE advection factor 23 13 SECTION SECTION SECTION TSHELL Purpose Define section properties for thick shell elements Card Format Card 1 1 2 3 4 5 6 7 8 SECID ELFORM SHRF NIP PROPT EN ICOMP NN Default 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 SHRF Shear factor A value of 5 6 is recommended NIP Number of through shell thickness integration points EQ 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 23 14 SECTION LS DYNA3D Version 936 VARIABLE QR ICOMP Bl B2 B3 B8 Bnip SECTION 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 material angle is defined for each through thickness integration point For each layer one integration point is used material angle at first integration point same procedure for determining material directions is use for thi
262. can be used Then the table input in DEFINE TABLE has to be used see Figure 19 5 LS DYNA3D Version 936 19 69 MAT MAT Figure 19 5 Rate effects may be accounted for by defining a table of curves If a table ID is specified a curve ID is given for each strain rate see DEFINE TABLE Intermediate values are found by interpolating between curves Effective plastic strain versus yield stress is expected 19 70 MAT LS DYNA3D Version 936 MAT MAT GEOLOGIC CAP MODEL This is Material Type 25 This an inviscid two invariant geologic cap model This material model can be used for geomechanical problems or for materials as concrete see references cited below Card Format Card 1 1 2 3 4 5 6 7 8 Variable ALPHA THETA GAMMA BETA VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density BULK Initial bulk modulus K G Initial Shear modulus ALPHA Failure envelope parameter 04 LS DYNA3D Version 936 19 71 MAT MAT VARIABLE THETA GAMMA BETA R D VEC TOFF 19 72 MAT DESCRIPTION Failure envelope linear coefficient 0 Failure envelope exponential coefficient y Failure envelope exponent p Cap surface axis ratio Hardening law exponent Hardening law coefficient Hardening law exponent Xo Kinematic hardening coefficient c Kinematic hardening parameter Save the following variable for plotting in TAU
263. ce only as Al and A2 These variables do not apply to the master surface Card 5 1 2 3 4 5 6 7 8 5 8 CONTACT LS DYNA3D Version 936 CONTACT Additional Card required for RIGID contact Card 5 1 2 3 4 5 The following card is ready if the THERMAL option is specified These two optional cards are read unless card is found Either the first or the first and second optional cards may be defined The second card may not be defined independently 8 m Optional 1 2 3 4 Card 5 6 7 1 LS DYNA3D Version 936 5 9 CONTACT CONTACT Optional 1 2 3 4 5 6 7 8 Card gt gt gt i bolo VARIABLE DESCRIPTION CID Contact interface ID This must be a unique number NAME Interface descriptor It is suggested that unique descriptions are used 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 EQ 0 all segments are included for single surface contact 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 EQ 0 for single surface contact 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 su
264. ces 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 4 node shell elements and internal element sorting to allow full vectorization of right hand side force assembly During the past four years considerable progress has been made as may be seen in the chronology of the developments which follows During 1989 many extensions and developments were completed and in 1990 the following capabilities were delivered to users e arbitrary node and element numbers e fabric model for seat belts and airbags composite glass model e vectorized type 3 contact and single surface contact L4 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION e many more I O options e all shell materials available for 8 node brick shell e Strain rate dependent plasticity for beams e fully vectorized iterative plasticity e interactive graphics on some computers e nodal damping e shell thickness taken into account in shell type 3 contact shell thinning accounted for in type 3 and type 4 contact e soft stonewalls e print suppression option for node and element data e massless
265. ching 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 DYNA3D Version 936 10 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 10 2 DEFORMABLE TO RIGID LS DYNA3D Version 936 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 ora ome LS DYNA3D Version 936 10 3 DEFORMABLE TO RIGID DEFORMABLE TO RIGID VARIABLE SWSET CODE TIME 1 TIME 2 TIME 3 ENTNO RELSW NCSF DTMAX D2R DESCRIPTION Set number for this automatic switch set Must be unique Activation switch code Defi
266. ck 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 Dnip material angle at nipth integration point Define as many cards as necessary until NIP points are defined LS DYNA3D Version 936 23 15 SECTION SET SET The keyword SET provides 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 is numbered separately The keyword control cards in this section are defined in alphabetical order SET BEAM SET DISCRETE SET NODE OPTION SET PART OPTION SET SEGMENT SET SHELL OPTION SET SOLID SET TSHELL LS DYNA3D Version 936 24 1 SET SET SET BEAM Purpose Define a set of beam elements Card Format Card 1 1 VARIABLE DESCRIPTION SID Set ID First beam element K2 Second beam element KNUM Last beam element 24 2 SET LS DYNA3D Version 936 SET SET DISCRETE Purpose Define a set of discrete elements Card Format Card 1 1 VARIABLE DESCRIPTION SID Set ID First discrete element K2 Second discrete element KNUM Last discrete element LS DYNA3D Version 936 24 3 SET SET SET NODE OPTION Available options include LIST COLUMN Purpose Define a nodal se
267. computer speed in 1976 was less than today s desktop workstation Furthermore the primitive sliding interface had only the capability to treat logically regular interfaces that are rather uncommon in most finite element discretizations of complicated three dimensional geometries This early version of DYNA3D contained truss membrane and solid elements The solid elements ranged from a one point quadrature eight noded element to a twenty noded element with eight point integration Due to the high cost of the twenty node solid the zero energy modes related to under 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 In an attempt to alleviate these drawbacks a new version of DYNA3D was released in 1979 that was programmed to provide near optimal speed on the CRAY 1 computers contained an improved sliding interface treatment that permitted triangular segments and was an order of magnitude faster than the previous 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 of Wilkins et al 1974 DYNAJ3D has been used continuously since 1979 The 1981 version Hallquist 1981a evolved from the 1979 version Nine additional material models were added to allow a much broader range
268. coupled with USA NBEAM Number of beam elements This is the number defined in the USA input file and is required for LS DYNA3D solely for the purpose of memory allocation It is assumed that each beam that is input into USA has a corresponding beam in the LS DYNA3D input file The 4 node surface segment normals must point into the fluid The total number of beams is then summed over all cards that are input If beams are defined in USA NBEAM should be nonzero only on one card in this section When running a coupled problem with USA the procedure involves several steps First LS DYNA3D is executed to create a linking file dyna pre used by USA and a dump file d3dump The execution lines are LS DYNA3D gt outputfilename0 cr i inputfilename cr 3 20 BOUNDARY LS DYNA3D Version 936 BOUNDARY Where we note that no prompt is provided for the second line of the input and that cr means that the carriage return key should be pressed Then it is necessary to create the fluid mass matrix by running the code FLUMAS FLUMAS lt flumasinputfilename gt flumasoutputfilename The ouput file from the LS DYNA3D run dyna pre is referenced in the input file to FLUMAS Next the code AUGMAT which initializes constants and arrays for the staggered solution procedure for the transient analysis is executed AUGMAT augmatinputfilename gt augmatoutputfilename Finally the coupled solution can begin by again executing LS DYNA3D
269. cts The addition of rate effects necessitates twelve additional history variables per integration point The cost and memory overhead of this model comes primarily from the need to remember the local system of principal stretches Typical unloading Typical unloading for curves determined by a large shape factor the hysteretic unloading e g 5 8 and a small factor With the shape hysteretic factor e g factor equal to unity 010 Unloading curves strain strain Figure 19 12 Behavior of the low density urethane foam model 19 146 MAT LS DYNA3D Version 936 MAT MAT COMPOSITE FAILURE MODEL This is Material Type 59 Card Format Card 1 1 2 3 4 5 6 7 8 PRBA PRCA PRCB Card 2 GAB MAFLAG Card 3 Card 4 Card 5 LS DYNA3D Version 936 19 147 MAT MAT Card 6 Variable Type VARIABLE MID RO EA EB EC PRBA PRCA PRCB GAB GBC GCA 19 148 MAT DESCRIPTION Material identification Density Ea Young s modulus longitudinal direction Ep Young s modulus transverse direction Ec Young s modulus normal direction Vba Bulk modulus of failed material LS DYNA3D Version 936 VARIABLE AOPT MAFLAG XP YP ZP Al A2 A3 V2 D1 D2 D3 TSIZE ALP SOFT FBRT SR SF XC XT YC YT 5 LS DYNA3D Version 936 MAT DESCRIPTION Material axes option EQ 0 0 locally orthotropic with material axes de
270. curve Default 1 0 This factor scales load curve ID LCIDRF above 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 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 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 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 consequent treatment of contact Normal failure force Only tensile failure i e tensile normal forces will be considered in the failure criterion Shear failure force 5 13 CONTACT CONTACT VARIABLE NEN MES NFLS SFLS TBLCID LCID FCM US CF HTC GCRIT GMAX 5 14 CONTACT
271. d recom mended EQ 2 Belytschko Tsay default 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 LS DYNA3D Version 936 6 21 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 6 22 CONTROL LS DYNA3D Version 936 CONTROL CONTROL STRUCTURED Purpose Write out a LS DYNA3D structured input deck for Version 930 This input deck will not support all capabilities that are available in Version 930 As a result some data such as load curve numbers will be output in an internal numbering system LS DYNA3D Version 936 6 23 CONTROL CONTROL CONTROL SUBCYCLE Purpose Control time step subcycling This feature is described in the LS DYNA3D Theoretical Manual Section 20 2 May be detrimental in cases of vectorized computation This keyword activates subcycling 6 24 CONTROL LS DYNA3D Version 936 CONTROL CONTROL TERMINATION Purpose Stop the job Card Format Default Remarks VARIABLE DESCRIPTI
272. d structural thermal analysis to be changed These parameters were initially defined on the CONTROL THERMAL cards Two cards are defined for this option Card Format Card 1 of 2 1 2 3 4 5 6 7 8 Card Format Card 2 of 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TS Thermal time step code EQ 0 No change EQ 1 Fixed timestep EQ 2 variable timestep DT Thermal time step on restart EQ 0 No change TMIN Minimum thermal timestep EQ 0 No change TMAX Maximum thermal timestep EQ 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 EQ 0 No change REFMAX Maximum number of reformations per thermal time step EQ 0 No change 29 12 RESTART LS DYNA3D Version 936 RESTART VARIABLE DESCRIPTION TOL Non linear convergence tolerance EQ 0 No change LS DYNA3D Version 936 29 13 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 VARIABLE DESCRIPTION NID Node ID 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 Ifa node is initialized on
273. d Format Card 1 1 2 3 4 5 6 7 8 YLD BHT XBO YBO ZBO TBO TALC SFLC Default Remarks Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION YLD Yield Kt 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 18 8 LOAD LS DYNA3D Version 936 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 divided by yield 103 Dorigin space time see DEFINE CURVE and remark below CFL Conversion factor kft to LS DYNA3D length units CFT Conversion factor milliseconds to LS DYNA3D time units CFP Conversion factor psi to LS DYNA3D pressure units Remark 1 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 yield U3 and multiplying that value by yield LS DYNA3D Version 936 18 9 LOAD LOAD LOAD DENSITY DEPTH Purpose Define density versus depth for gravity loading This option has been occasionally used for analyzing underground
274. damping EQ n Inl is the load curve ID giving the damping force versus relative normal velocity see comment below CF Coulomb friction coefficient Assumed to be constant INTORD 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 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 BT Birth time DT Death time LS DYNA3D Version 936 5 21 CONTACT CONTACT VARIABLE DESCRIPTION SO Flag to use penalty stiffness as in surface to surface contact EQ 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 EQ 0 mesh is not generated EQ 1 mesh is generated XC x center see comments below YC y center yc see comments below ZC z center zc See comments below AX x direction for local axis A Ax see comments below AY y direction for local axis A Ay see comments below AZ z direction for local axis A Az see comme
275. dependency of stress and effective plastic strain can be defined via a load curve This plasticity model is fully iterative and is available only for shell elements Also see the notes below Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic hardening modulus R Anisotropic hardening parameter HLCID Load curve ID defining effective yield stress versus effective plastic strain Consider Cartesian reference axes which are parallel to the three symmetry planes of anisotropic behavior Then the yield function suggested by Hill 1948 can be written F o055 Soay T on H o dg 2165 2 2 2NG 5 1 0 where and are the tensile yield stresses and 12 23 are the shear yield stresses The constants F G H L M and N are related to the yield stress by LS DYNA3D Version 936 19 113 MAT MAT 2 1 623 2M 2 1l 2 9 y31 y 2 9 y12 rete 4 28 l 6 2 1 1 1 2 2s 1 The isotropic case of von Mises plasticity can be recovered by setting F G i3 20 L M N For the particular case of transverse anisotropy where properties do not vary in the xj x2 plane the following relations hold 2F 2G l
276. determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the 1 2 3 4 segment determined by taking the cross product of the vector v defined below with the segment normal vector Coordinates of point p for AOPT 1 Components of vector a for AOPT 2 Components of vector d for AOPT 2 For efficiency it is strongly recommended that the load curve ID s LCA LCB LCC LCS LCAB LCBC and LCCA contain exactly the same number of points with corresponding strain values on the abcissa If this recommendation is followed the cost of the table lookup is insignificant Conversely the cost increases significantly if the abcissa strain values are not consistent between load curves 19 80 MAT LS DYNA3D Version 936 MAT The behavior before compaction is orthotropic where the components of the stress tensor are uncoupled i e an a component of strain will generate resistance in the local a direction with no coupling to the local b and c directions The elastic moduli vary from their initial values to the fully compacted values at Vr linearly with the relative volume V Eaa Eaau R E Eaau Epb Ebbu BCE E
277. dulus greatly exceeds the shear modulus in magnitude To model the rubber as an unconstrained material a hydrostatic work term Wy J is included in the strain energy functional which is function of the relative volume J Ogden 1984 W j J5 J 9 Cps 71 3 25 3f Wa 4 p q 0 1 2 In order to prevent volumetric work from contributing to the hydrostatic work the first and second invarients are modified as shown This procedure is described in more detail by Sussman and Bathe 1987 The effects of confined air pressure in its overall response characteristics is included by augmenting the stress state within the element by the air pressure oj oj r where oj is the bulk skeletal stress and o is the air pressure computed from the equation gir Poy 1 9 where po is the initial foam pressure usually taken as the atmospheric pressure and defines the volumetric strain Y V 1 Y0 19 212 MAT LS DYNA3D Version 936 MAT where V is the relative volume of the voids and Yo is the initial volumetric strain which is typically zero The rubber skeletal material is assumed to be incompressible Rate effects are taken into account through linear viscoelasticity by a convolution integral of the form t Oi 7 Sita t or in terms of the second Piola Kirchhoff stress S ij and Green s strain tensor Ei t OE Sij Gijkl t 5 where gjjj t v and 1
278. e assumed to be covered by planar surfaces 1 2 AIRBAG LS DYNA3D Version 936 AIRBAG and 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 Pfemodel 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 Vevolume V sca V femodel Vini Pfemodel Psca Pevolume Damping can be applied to the structure enclosing a control volume by using a mass weighted damping formula F mib V Vog where F is the damping force is the nodal mass V is the velocity for a node Vog 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 ypV2 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 to 1 and has to be chosen by the user Small value
279. e general formulation Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density BULK Elastic bulk modulus GO Short time shear modulus see equations below GI Long time infinite shear modulus BETA Decay constant The shear relaxation behavior is described by Hermann and Peterson 1968 G t Goo Go A Jaumann rate formulation is used U oj 2 V where the prime denotes the deviatoric part of the stress rate and the strain rate Dij LS DYNA3D Version 936 19 23 MAT MAT MAT BLATZ KO RUBBER This is Material Type 7 This one parameter material allows the modeling of nearly incompressible continuum rubber The Poisson s ratio is fixed to 0 463 Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus The second Piola Kirchhoff stress is computed as 1 Wee lee 5 6 ca 1 20 where V is the relative volume defined as being the ratio of the current volume to the initial volume Cij is the right Cauchy Green strain tensor and v is Poisson s ratio which is set to 463 internally This stress measure is transformed to the Cauchy stress according to the relationship V Fik Sik where Fj is the deformation gradient tensor Also see Blatz and 1962
280. e Element Analysis in Struct Mech Eds W Wunderlich E Stein and K J Bathe Springer Verlag Berlin 151 168 1981c 30 4 REF LS DYNA3D Version 936 REFERENCES Johnson G C and D J Bammann A discussion of stress rates in finite deformation problems Int J Solids Struct 20 725 737 1984 Johnson G R and W H Cook A Constitutive Model and Data for Metals Subjected to Large Strains High Strain Rates and High Temperatures Presented at the Seventh International Symposium on Ballistics The Hague The Netherlands April 1983 Kenchington G J A Non Linear Elastic Material Model for DYNA3D Proceedings of the DYNA3D Users Group Conference September 1988 published by Boeing Computer Services Europe Limited Key S W HONDO A Finite Element Computer Program for the Large Deformation Dynamic Response of Axisymmetric Solids Sandia National Laboratories Albuquerque N M Rept 74 0039 1974 Krieg R D and S W Key Implementation of a Time Dependent Plasticity Theory into Structural Computer Programs Vol 20 of Constitutive Equations in Viscoplasticity Computational and Engineering Aspects American Society of Mechanical Engineers New York N Y 1976 pp 125 137 Lee E L and C M Tarver Phenomenological Model of Shock Initiation in Heterogenous Explosives PHYS Fluids Vol 23 p 2362 1980 MADYMO3D USER S MANUAL Version 4 3 TNO Road Vehicles Research Institute Depar
281. e 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_RIGID 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 Card Format Card 1 Default Remarks LS DYNA3D Version 936 21 1 PART PART Card 2 2 4 5 6 1 3 7 Additional Cards are required for the INERTIA option Card 3 1 2 3 4 5 6 7 8 Card 4 1 2 3 4 5 6 7 8 Card 5 1 2 3 4 5 6 7 8 21 2 PART LS DYNA3D Version 936 PART Optional card required for the IRCS 1 Card 6 1 2 3 4 5 6 7 8 Remark Additional Card is required for the REPOSITION option Optional 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION HEADING Heading for the part PID Part identification SECID Section identification defined in SECTION 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
282. e acts in the negative t direction 18 18 LOAD LS DYNA3D Version 936 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 18 3 Card Format Default Remarks 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 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled LS DYNA3D Version 936 18 19 LOAD 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 Form
283. e currently using these databases Table 8 1 Nodal Quantities Component Number Quantity 1 3 X y Z displacements 4 6 X y Z velocities 7 9 X y Z accelerations 10 temperature Table 8 2 Brick Element Quantities Component Number Quantity 1 x stress y stress z stress xy stress yz stress ZX Stress effective plastic strain 8 10 DATABASE LS DYNA3D Version 936 DATABASE Table 8 3 Shell and Thick Shell Element Quantities Component Number Quantity 1 00 10 FW WN WON NN NN NN WN N YR RRR v tA _ DN FP KF C LS DYNA3D Version 936 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 outer surface effective plastic strain bending moment mxx 4 node shell bending moment myy 4 node shell bending moment mxy 4 node shell shear resultant qxx 4 shell shear resultant qyy 4 shell normal resultant nxx 4 node shell normal resulta
284. e 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 DYNA3D requires more space it is recommended that the sel be increased appropriately Using C cpu defines the maximum cpu usage allowed that if exceeded will cause LS DYNA3D to 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 DYNA3D I inf O otf G ptf D dpf 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 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 execution lines are acceptable LS DYNA3D I inf LS DYNA3D 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 DYNA3D I inf Z isfl LS DYNA3D Version 936 1 35 INTRODUCTION INTRODUCTION and in the second by LS DYNA3D I inf L isf1 Batch execution in
285. e 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 Default Card 2 1 2 3 4 5 6 7 8 Variable Type 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 18 28 LOAD LS DYNA3D Version 936 LOAD VARIABLE DESCRIPTION TB Base temperature LCID Load curve ID that multiplies the scaled temperature see DEFINE_ CURVE TSE Scaled temperature of the exempted nodes optional TBE Base temperature of the exempted nodes optional LCIDE Load curve ID that multiplies the scaled temperature of the exempted nodes optional see DEFINE CURVE Remark 1 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 LS DYNA3D Version 936 18 29 LOAD LOAD LOAD THERMAL VARIABLE NODE Purpose Define nodal temperature that are variable during the ca
286. e 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 begins 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
287. e 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 LS DYNA3D Version 936 11 5 ELEMENT ELEMENT ELEMENT MASS Purpose Define a lumped mass element assigned to a nodal point Card Format 218 16 0 Variable VARIABLE DESCRIPTION EID Element ID A unique number must be used NID Node ID Node to which the mass is assigned MASS Mass value 11 6 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SEATBELT Purpose Define a seat belt element Card Format 518 E16 0 1 2 3 4 9 6 7 8 9 10 T eS i TET di VARIABLE DESCRIPTION EID Element ID A unique number has to be used PID Part ID N1 Node 1 ID N2 Node 2 ID SBRID Retractor ID see ELEMENT SEATBELT RETRACTOR SLEN Initial slack length Remarks 1 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 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 ini
288. e is a sample pfile with every possible option specified directory global rundir local tmp rundir contact bucket 250 ntrack 4 maxiter 12 inititer 6 bufnumsf 2 bufsizesf 1 L54 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION bigmem decomposition file dcfile32 numproc 64 costinc 10 method rcb show Modeling Tips on MPP s Due to the nature of the parallel contact algorithm it is more efficient to have as few contact interfaces as possible For example a metal forming problem might traditionally be set up with several contact surfaces blank die blank binder blank punch etc Speed increases may be obtained by replacing these with a single contact surface with the blank as slave and die binder and punch all on the master surfaces The total amount of contact to be computed may be the same but the computation might run faster Similarly for crash applications it will almost always be faster to create one large type 13 contact region rather than many small contact interfaces LS DYNA3D Version 936 L55 INTRODUCTION AIRBAG AIRBAG 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 OPTION AIRBAG REFERENCE GEOMETRY AIRBAG OPTION Options include the following thermodynamic relationships SI
289. e is assumed for this vector the specified coordinates are non unique and define only a direction 3 16 BOUNDARY LS DYNA3D Version 936 BOUNDARY BOUNDARY SPC OPTION Available options include NODE SET Purpose Define nodal single point constraints Card Format Variable NID NSID CID DOFX DOFY DOFZ DOFRX DOFRY DOFRZ Default VARIABLE DESCRIPTION NID NSID Node ID or nodal set ID see SET NODE CID 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 Constraints are applied if a value of 1 is given for DOFxx A value of zero means no constraint LS DYNA3D Version 936 3 17 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 average stress in the elements surrounding the boundary nodes in a direction perpendicular to the boundary is used VTX x coordinate of tail of a normal
290. e nominal stress versus strain along b axis Strain is defined as Ap 1 where Ap is the stretch ratio along the b axis Failure strain A 1 Time step for automatic element erosion Damping coefficient Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE_COORDINATE_NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector Xp Zp define coordinates of point p for AOPT 1 a2 define components of vector a for AOPT 2 d dz d3 define components of vector d for AOPT 2 V1 V2 V3 define components of vector v for AOPT 3 LS DYNA3D Version 936 MAT MAT USER DEFINED MATERIAL MODELS These are Material Types 41 50 The user can supply his own subroutines See also Appendix A The keyword input has to be used for the user inter
291. e 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 1 26 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION INTERFACE DEFINITIONS FOR COMPONENT ANALYSIS Interface definitions for component analyses are used to define surfaces nodal lines or 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 master surfaces of type TIED SURFACE TO SURFACE sliding interfaces of Section 31 as master lines in the tie breaking shell definitions or as the controlling nodes for determining the motion of single nodal points 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 DYNA3D command line When starting the second analysis the name of
292. e problem assigned to processor 0 and so on The problem will not actually be run but the code will terminate once the initial D3PLOT state has been written e Contact Holds contact specific option Any conflicting option that might be specified in the problem itself in accordance with the 920 version manual are ignored bucket n Specifies the frequency for bucket sort contact searches Default 200 ntrack n Specifies the number of contact segments to keep track of per slave node Increasing this number requires more storage and will have some impact on speed For sheet metal stamping problems values of 1 or 2 are probably adequate depending on the problem configuration and definition of contact interfaces Default 3 maxiter n Specifies the maximum number of Newton iterations while finding the contact point during bucket sort searches Iteration will continue until the parametric coordinates of contact point change by less than 5 of the segment size or the maximum number of iterations is achieved Default 8 inititer n During contact interface initialization an attempt is made to move the slave nodes to eliminate initial penetrations An iterative approach is used since moving the nodes in one direction may cause problems in a different direction particularly with the single sided contact options This parameter specifies the maximum number of iterations to attempt After the final iteration any nodes which still
293. eaches the plastic moment The moment versus rotation relationship is specified by the user in the form of a load curve and scale factor The points of the load curve are plastic rotation in radians plastic moment Both quantities should be positive for all points with the first point being zero initial plastic moment Within this constraint any form of characteristic may be used including flat or falling curves Different load curves and scale factors may be specified at each node and about each of the local s and t axes Axial collapse occurs when the compressive axial load reaches the collapse load Collapse load versus collapse deflection is specified in the form of a load curve The points of the load curve are either true strain collapse force or change in length collapse force Both quantities should be entered as positive for all points and will be interpreted as compressive The first point should be zero initial collapse load The collapse load may vary with end moment as well as with deflections In this case several load deflection curves are defined each corresponding to a different end moment Each load curve should have the same number of points and the same deflection values The end moment is defined as the average of the absolute moments at each end of the beam and is always positive Stiffness proportional damping may be added using the damping factor A This is defined as follows where 5 is the damping factor at
294. ector d for AOPT 2 The anisotopic yield criterion for plane stress is defined as t Kj a Ki Kj 267 where Oy is the yield stress and Kj 2 are given by The anisotropic material constants a c h and p are obtained through Roo R45 and 2 2 Roo _ Roo 2 p Ro 1 Roo The anisotropy parameter p is calculated implicitly According to Barlat and Lian the R value width to thickness strain ratio for any angle can be calculated from LS DYNA3D Version 936 19 111 MAT MAT 2moy a a 1 Ry where is the uniaxial tension in the direction This expression can be used to iteratively calculate the value of p Let 45 and define a function g as 2moy a 1 Ras 8 An iterative search is used to find the value of p For face centered cubic FCC materials m 8 is recommended and for body centered cubic BCC materials m 6 may be used The yield strength of the material can be expressed in terms of k and n Oy where o is the strain corresponding to the initial yield stress and is the plastic strain 19 112 MAT LS DYNA3D Version 936 MAT MAT TRANSVERSELY ANISOTROPIC ELASTIC PLASTIC This is Material Type 37 This model is for simulating sheet forming processes with anisotropic material Only transverse anisotropy can be considered Optionally an arbitrary
295. ed Others are excluded optional T Temperature TE Temperature of exempted nodes optional 18 24 LOAD LS DYNA3D Version 936 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 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 Variable Type Default VARIABLE DESCRIPTION NID Node ID T Temperature LS DYNA3D Version 936 18 25 LOAD LOAD LOAD THERMAL LOAD CURVE Purpose Nodal temperatures will be uniform throughout the model and will vary according to a load curve It is assumed that the temperatures refer to a null state at the beginning and are thus relative temperatures They dynamically load the structure Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID see DEFINE_CURVE to define temperature versus time 18 26 LOAD LS DYNA3D Version 936 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 DYNA3D Version 936 18 27 LOAD LOAD LOAD THERMAL VARIABLE Purpose Define nodal sets giving the temperature that is variabl
296. ed as the vector cross product of the z axis vector and the x axis vector LS DYNA3D Version 936 21 5 PART RIGIDWALL RIGIDWALL Two keywords are used in this section to define rigid surfaces RIGIDWALL GEOMETRIC OPTION OPTION RIGIDWALL PLANAR OPTION OPTION LS DYNA3D Version 936 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 Card Format 1 of 3 Card 1 1 2 3 4 5 6 7 8 Default 22 2 RIGIDWALL LS DYNA3D Version 936 RIGIDWALL Card Format 2 of 3 Card 2 1 2 3 4 5 6 7 8 Variable Type Default Remarks Card Format 3 of 3 Required if FLAT is specified after the keyword A plane with a 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
297. ed if THICKNESS or BETA is specified after the keyword 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION EID Element ID Unique numbers have to be chosen PID Part ID see PART N1 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 4 below Remarks 1 Default values in place of zero shell thicknesses are taken from the cross section property definition of the PID 2 Beta is defined only for anisotropic materials 11 24 ELEMENT LS DYNA3D Version 936 ELEMENT 3 Counterclockwise node numbering determines the top surface see Figure 11 5 4 To allow for an arbitrary orientation of the shell elements within the finite element mesh each ply in the composite has a unique 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 y which can be defined for each element on the element card and is measured from the 1 2 element side Figures 11 6 and 11 7 depict these angles LS DYNA3D Version 936 11 25 ELEMENT ELEMENT Ny n 3 Figure 11 5
298. ed 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 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 NASTRAN BDF file is written for users at General Motors Each ASCII database is written at its own unique output interval defined in the user input LS DYNA3D Version 936 L41 INTRODUCTION INTRODUCTION File Organization ASCII Experimental ae e Database Data C save file for commands S tsave PostScript plot video output PAL NTSC Figure I 4 1 42 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION EXECUTION SPEEDS The execution speeds on the Cray YMP for various elements in LS DYNA3D are tabulated below in microseconds per element cycle Element Type CPU Cost 8 node solid with 1 point integration and default 12 hourglass control as above but with Flanagan Belytschko hourglass 15 control constant stress and Flanagan Belytschko hourglass 20 control i e the Flanagan Belytschko element 4 node Belytschko Tsay shell with four thickness 11 integration points 4 node Belytschko Tsay shell with resultant plasticit
299. ed z rotation Any combination of local constraints can be achieved by adding the number 1 into the corresponding column LCO Local coordinate system number for output See DEFINE_ COORDINATE OPTION Alternative method for specifying local system below 1 3 Define two vectors a and v fixed in the rigid body which are used for output and the user defined airbag sensor subroutines The output parameters are in the directions a b and c where the latter are given by the cross products and b cxa This input is optional 19 56 MAT LS DYNA3D Version 936 MAT Remark l The material constants are used for determining sliding interface parameters if the rigid body interacts along sliding interfaces Realistic values for these constants should be defined LS DYNA3D Version 936 19 57 MAT MAT MAT ORTHOTROPIC THERMAL This is Material Type 21 A linearly elastic material with orthotropic temperature dependent coefficients can be defined Card Format Card 1 1 2 3 4 5 6 7 8 PRBA PRCA PRCB Card 2 Card 3 4 19 58 LS DYNA3D Version 936 VARIABLE MID RO EA EB EC PRBA PRCA PRCB GAB GBC GCA AA AC AOPT XP YP ZP A1 A2 A3 LS DYNA3D Version 936 MAT DESCRIPTION Material identification A unique number has to be chosen Mass density Young s modulus in a direction Ep Young s modulus in b direction Ec You
300. ee NODE OPTION EPPF Plastic strain at failure Remarks 1 plastic strain taken for the failure criteria is computed as an average volume weighted plastic strain from the shell elements surrounding both node sets Each node set is considered separately when the plastic strains are computed LS DYNA3D Version 936 4 41 CONSTRAINED CONSTRAINED CONSTRAINED TIED NODES FAILURE Purpose Define a tied node set with failure based on plastic strain The nodes must be coincident Card Format Default Remarks VARIABLE DESCRIPTION NSID Nodal set ID see NODE OPTION EPPF Plastic strain at failure This feature applies only to thin shell elements 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 4 42 CONSTRAINED LS DYNA3D Version 936 CONTACT CONTACT CONTACT_ OPTION1 OPTION2 _ OPTION3 Purpose Define a sliding contact interface OPTIONI specifies the contact type also see remarks 1 3 below AIRBAG SINGLE SURFACE AUTOMATIC NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE CONSTRAINT NODES TO SURFACE CONSTRAINT SURFACE TO SURFACE DRAWBEAD ERODING NODES TO SURFACE ERODING SINGLE SURFACE ERODING SURFACE TO
301. ee DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT LT 0 function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation AOPT Material axes definition EQ 0 locally orthotropic with material axes by element nodes N1 and EQ 1 locally orthotropic with material axes determined by a point in space and global location of element center EQ 2 globally orthotropic with material axes determined by vectors HC Heat capacity Thermal conductivity K in local x direction K2 Thermal conductivity K2 in local y direction K3 Thermal conductivity K3 in local z direction XP YP ZP Define coordinate of point p for AOPT 1 A1 A2 A3 Define components of vector a for AOPT 2 D1 D2 D3 Define components of vector v for AOPT 2 LS DYNA3D Version 936 19 233 MAT MAT MAT THERMAL ISOTROPIC TD This is thermal material property type 3 It allows temperture dependent isotropic properties to be defined The temperature dependency is defined by specifying a minimum of two and a maximum of eight data points The properties must be defined for the tempertaure range that the material will see in the analysis Card Format 1 of 4 1 2 3 4 5 6 7 8 Card Format 2 of 4 Type Type 19 234 MAT LS DYNA3D Version 936 MAT Card Format 4 of 4 Type VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be ch
302. elative volume for erosion in compression Typically use values 0 less than unity If zero erosion in compression is inactive YM Young s modulus used for null beams and shells only LS DYNA3D Version 936 19 27 MAT MAT VARIABLE DESCRIPTION PR Poisson s ratio used for null beams and shells only The null material must be used with an equation of state Pressure cutoff is negative in tension A viscous stress of the form is computed for nonzero u where amp is the deviatoric strain rate 19 28 MAT LS DYNA3D Version 936 MAT MAT ELASTIC PLASTIC HYDRO This is Material Type 10 This material allows the modeling of an elastic plastic hydynamic material Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 EPS11 EPS 12 EPS 13 EPS14 EN Card 4 P F EPS15 EPS16 F ES7 F i LS DYNA3D Version 936 19 29 MAT MAT Card 5 ES9 ES10 ES11 ES12 ES13 ES14 ES15 ES16 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus SIGY Yield stress see comment below EH Plastic hardening modulus see definition below PC Pressure cutoff lt 0 0 If zero a cutoff of is assumed EPS Effective plastic strain logrithmic Define up to 16 values Care must be taken that the full range of strains expected in the analysis is covered Linear extrapolation is used if the s
303. em and the final stress state is computed ot _ sk O77 LS DYNA3D Version 936 19 137 MAT MAT MAT ENHANCED COMPOSITE DAMAGE These are Material Types 54 55 which are enhanced versions of the composite model material type 22 Arbitrary orthothropic materials e g unidirectional layers in composite shell structures can be defined Optionally various types of failure can be specified following either the suggestions of Chang and Chang 1984 or Tsai and Wu 1981 In addition special measures are taken for failure under compression See Matzenmiller and Schweizerhof 1990 This model is only valid for thin shell elements Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Type Card 3 Type Card 4 Variable 19 138 MAT LS DYNA3D Version 936 Card 5 Card 6 MAT VARIABLE MID RO EA EB EC PRBA PRCA PRCB GAB GBC GCA DESCRIPTION Material identification A unique number has to be chosen Mass density Ea Young s modulus longitudinal direction Ep Young s modulus transverse direction Ec Young s modulus normal direction Vba Poisson s ratio ba Vca Poisson s ratio ca Veb Poisson s ratio cb Gab Shear modulus ab Gbc Shear modulus bc Gea shear modulus ca Bulk modulus of failed material LS DYNA3D Version 936 19 139 MAT MAT VARIABLE AOPT XP YP ZP Al A2 V2 D1 D2 D3 TFAIL XC SOFT FBRT
304. endix F Programs CAL3D and MADYMO INTRODUCTION LS DYNA3D is coupled to occupant simulation codes to generate solutions in automotive crashworthiness that include occupants interacting with the automotive structure In such applications LS DYNA3D provides the simulation of the structural and deformable aspects of the model and the OSP Occupant Simulation Program simulates the motion of the occupant There is some overlap between the two programs which provides flexibility in the modeling approach For example both the OSP and LS DYNA3D have the capability of modeling seat belts and other deformable restraints The advantage of using the OSP is related to the considerable databases and expertise that have been developed in the past for simulating dummy behavior using these programs The development of the interface provided LSTC a number of possible approaches The approach selected is consistent with the LSTC philosophy of providing the most flexible and useful interface possible This is important because the field of non linear mechanics is evolving rapidly and techniques which are used today are frequently rendered obsolete by improved methodologies and lower cost computing which allows more rigorous techniques to be used This does make the learning somewhat more difficult as there is not any single procedure for performing a coupling One characteristic of LS DYNA3D is the large number of capabilities particularly those associated with rigid bod
305. ents 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 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 4 Two methods are used in LS DYNA3D 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 NODES TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE AUTOMATIC SINGLE SURFACE AUTOMATIC SURFACE TO SURFACE 5 4 CONTACT LS DYNA3D Version 936 CONTACT 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 Nodal normal projection Segment based projectio
306. ents 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 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 2 This is an ad hoc parameter which should probably not be used LS DYNA3D Version 936 18 21 LOAD LOAD 3 The output files named pressure 1 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 4 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 1s used to enable the calculation to be carried out in real time 18 22 LOAD LS DYNA3D Version 936 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 LOAD THERMAL OPTION method are all applied in
307. ept by At below TREM At for element removal EQ 0 0 At is not considered default GT 0 0 element eroded if element time step size falls below At When the effective plastic strain reaches the failure strain or when the pressure reaches the failure pressure the element loses its ability to carry tension and the deviatoric stresses are set to Zero i e the material behaves like a fluid If t for element removal is defined the element removal option is ignored The element erosion option based on At must be used cautiously with the contact options Nodes to surface contact is recommended with all nodes of the eroded brick elements included in the node list As the elements are eroded the mass remains and continues to interact with the master surface 19 38 MAT LS DYNA3D Version 936 MAT MAT SOIL AND FOAM FAILURE This is Material Type 14 The input for this model is the same as for MATERIAL SOIL AND FOAM Type 5 however when the pressure reaches the failure pressure the element loses its ability to carry tension It should be used only in situations when soils and foams are confined within a structure or when geometric boundaries are present LS DYNA3D Version 936 19 39 MAT MAT MAT JOHNSON COOK This is Material Type 15 The Johnson Cook strain and temperature sensitive plasticity is sometimes used for problems where the strain rates vary over a large range and adiabatic temperature increases due to plastic
308. er 0 lt B lt 1 See comments below LS DYNA3D Version 936 19 13 MAT MAT VARIABLE DESCRIPTION SRC Strain rate parameter C for Cowper Symonds strain rate model see below If zero rate effects are not considered SRP Strain rate parameter P for Cowper Symonds strain rate model see below If zero rate effects are not considered FS Failure strain for eroding elements Strain rate is accounted for using the Cowper and Symonds model which scales the yield stress with the factor where is the strain rate ignore strain rate effects set both SRC and SRP to zero Kinematic isotropic or a combination of kinematic and isotropic hardening may be specified by varying B between 0 and 1 For equal to O and 1 respectively kinematic and isotropic hardening are obtained as shown in Figure 19 2 For isotropic hardening B 1 Material Model 12 MAT ISOTROPIC ELASTIC PLASTIC requires less storage and is more efficient Whenever possible Material 12 is recommended for solid elements but for shell elements it is less accurate and thus material 12 is not recommend in this case 19 14 MAT LS DYNA3D Version 936 MAT B 0 kinematic hardening B isotropic hardening Figure 19 2 Elastic plastic behavior with kinematic and isotropic hardening where 10 and are undeformed and deformed lengths of uniaxial tension specimen is the slope of the bilinear stress strain curve LS DYNA3
309. ermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number see DEFINE_CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT LT 0 function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation AOPT Material axes definition EQ 0 locally orthotropic with material axes by element nodes N1 and N4 EQ 1 locally orthotropic with material axes determined by a point in space and global location of element center EQ 2 globally orthotropic with material axes determined by vectors T8 Temperatures T1 T8 8 Heat capacity at T1 T8 K1 Thermal conductivity in local x direction at T8 K2 K2 g Thermal conductivity K2 in local y direction at T1 T8 K3 1 K3 g Thermal conductivity K3 in local z direction at T1 T8 XP YP ZP Define coordinate of point p for AOPT 1 Al A2 A3 Define components of vector a for AOPT 2 D1 D2 D3 Define components of vector v for AOPT 2 19 238 MAT LS DYNA3D Version 936 MAT MAT THERMAL ISOTROPIC PHASE CHANGE This is thermal material property type 9 It allows temperture dependent isotropic properties with phase change to be defined The latent heat of the material is defined together with the solidus and liquidus temperatures The temperature dependency is defined by specifying a minimum of two and a maximum of eight data points The
310. erned by the expression 1 e Pt 2 The bulk viscosity which generates rate dependent pressure may cause an unexpected volumetric response and consequently it is optional with this model 3 The hysteretic unloading factor results in the unloading curve to lie beneath the loading curve as shown in Figure 19 12 This unloading provide energy dissipation which is reasonable in certains kinds of foam Rate effects are accounted for through linear viscoelasticity by a convolution integral of the form 1 eiii t dt LS DYNA3D Version 936 19 145 MAT MAT where t t is the relaxation function The stress tensor augments the stresses determined from the foam of consequently the final stress is taken as the summation of the 1 ij q y 1 two contributions Since we wish to include only simple rate effects the relaxation function is represented by one term from the Prony series N g t 00 oye 1 given by g t Ege Pi This model is effectively a Maxwell fluid which consists of a damper and spring in series We characterize this in the input by a Young s modulus and decay constant B The formulation is performed in the local system of principal stretches where only the principal values of stress are computed and triaxial coupling is avoided Consequently the one dimensional nature of this foam material is unaffected by this addition of rate effe
311. es 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 workers Belytschko and Marchertas 1974 Bazeley et al 1965 Belytschko et al 1984 and are frequently used since collapsed quadrilateral shell elements tend to lock and give very bad results LS DYNA3D automatically treats collapsed quadrilateral shell elements as C 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 1 22 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION 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
312. est 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 zero 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 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 29 20 RESTART LS DYNA3D Version 936 RESTART DAMPING GLOBAL Purpose Define mass weigthed nodal damping that applies globally to the deformable nodes Card Format Default 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 n VALDMP System damping constant d this option is bypassed if the load curve number defined above is nonzero LS DYNA3D Version 936 29 2 RESTART 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 force
313. estarts 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 e reset output printing interval e reset output plotting interval e delete contact surfaces e delete elements and parts e switch deformable bodies to rigid e switch rigid bodies to deformable e 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 DYNA3D I restartinput R D3DUMPnn where D3DUMPnn or whatever name is chosen for the family member is the n th restart file from the last run where the data is taken LS DYNA3D 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 DYNA3D Version 936 29 1 RESTART RESTART 29 2 RESTART DAMPING GLOBAL DATABASE OPTION DATABASE BINARY OPTION DE
314. event timestep problems It is used for time step calculations a long as is smaller than E It has to be carefully chosen to take into account the stiffening effects of the viscosity Both E and V are nonlinear with crush as follows E Ev Vj Vo abs 1 V 19 156 MAT LS DYNA3D Version 936 MAT where viscosity generates a shear stress given by T Voy Y is the engineering shear strain rate and V is the relative volume defined by the ratio of the current to initial volume Typical values are units of N mm s E 0 0036 nj 4 0 V2 0 0015 2 100 0 2 0 2 0 05 LS DYNA3D Version 936 19 157 MAT MAT MAT CRUSHABLE FOAM This is Material Type 63 which is dedicated to modeling crushable foam with optional damping and tension cutoff Unloading is fully elastic Tension is treated as completely elastic plastic Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio LCID Load curve ID defining yield stress versus volumetric strain y see Figure 19 13 TSC Tensile stress cutoff DAMP Rate senitivity via damping coefficient 05 lt recommended value lt 50 The volumetric strain is defined in terms of the relative volume V as y 1 V The relative volume is defined as the ratio of the current to the initial volume 19 158 MAT LS DYNA3D Version 936 MAT w z
315. eviatoric stress 12 3rd principal deviatoric stress 13 maximum shear stress 14 Ist principal stress 15 2nd principal stress 16 3rd principal stress 17 In v vO LS DYNA3D Version 936 H3 Appendix H FILE name GRID NOGRID OSCL OSET omin omax PRINT QUIT END T RDLC Z fp Zn TIMEc n 18 relative volume 19 v0 v 1 0 20 1st history variable 21 2nd history variable Adding 100 or 400 to component numbers 1 16 yields strains and strain rates respectively Change pampers filename to name for printing Graphics displays will be overlaid by a grid of orthogonal lines Graphics displays will not be overlaid by a grid of orthogonal lines Scale all ordinate data by f Default is f 1 Set min and max values on ordinate to omin and omax respectively If omin omax 0 scaling is automatic Print plotted time history data into file pampers Only data plotted after this command is printed File name can be changed with the file command Exit the material model driver program Redefine load curve m using n coordinate pairs r1 z1 2 22 Tn Zn Plot component c versus time Use terminal output device type n LS DYNA3D provides a list of available devices Presently the material model drive is implemented for solid and shell element material models The driver does not yet support material models for beam elements 4 LS DYNA3D Version 936
316. f inertia tensor set to zero if IRCS 1 Izz ZZ component of inertia tensor x rigid body translational velocity in global coordinate system y rigid body translational velocity in global coordinate system z rigid body translational velocity in global coordinate system x rigid body rotational velocity in global coordinate system y rigid body rotational velocity in global coordinate system z rigid body rotational velocity in global coordinate system LS DYNA3D Version 936 4 27 CONSTRAINED CONSTRAINED 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 local in plane vector YLIP y coordinate of local in plane vector ZLIP z coordinate of local in plane vector 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 rotation of the nodal sets is admissible Mass properties are determined from the nodal masses and coordinates Inertial properties are defined if and only if the INERTIA option is specified 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 a
317. f its shortest diagonal if the segment belongs to a solid element This option applies to the surface to surface contact algorithms 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 Scale factor on default slave penalty stiffness see also CONTROL_ CONTACT Scale factor on default master penalty stiffness see also CONTROL_ CONTACT 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 Optional thickness for master surface overrides true thickness This option applies only to contact with shell elements True thickness is the element thickness of the shell elements 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 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 Coulomb friction scale factor The Coulomb friction value is scaled as Usce FSF Uo see above Viscous friction scale factor If this factor is defined then the limiting force becomes VSF
318. f the Cap Model Consistent Return Algorithms and Rate Dependent Extension J Eng Mech Vol 114 No 2 191 218 19882 Simo J C J W Ju K S Pister and R L Taylor Softening Response Completeness Condition and Numerical Algorithms for the Cap Model Int J Numer Analy Meth Eng in press 1988b Steinberg D J and M W Guinan A High Strain Rate Constitutive Model for Metals University of California Lawrence Livermore National Laboratory Rept UCRL 80465 1978 Stillman D W and J O Hallquist INGRID A Three Dimensional Mesh Generator for Modeling Nonlinear Systems University of California Lawrence Livermore National Laboratory Rept UCID 20506 1985 Storakers B On Material Representation and Constitutive Branching in Finite Compressible Elasticity Royal Institute of Technology Stockholm Sweden 1985 Stout M G D E Helling T L Martin and G R Canova Int J Plasticity Vol 1 pp 163 174 1985 Taylor L M and D P Flanagan PRONTO3D A Three Dimensional Transient Solid Dynamics Program Sandia Report SAND87 1912 UC 32 1989 Tsai S W and E M Wu A General Theory of Strength for Anisotropic Materials J Composite Materials 5 1971 pp 73 96 VDA Richtlinier Surface Interfaces Version 20 Verband der Automobilindustrie e v Frankfurt Main Germany 1987 Wang J T and O J Nefske A New CAL3D Airbag Inflation Model SAE paper 880654 1988
319. f the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector 19 124 MAT LS DYNA3D Version 936 VARIABLE MAXC XP YP ZP Al A2 V2 D1 D2 D3 2 P4 PLCM MAT DESCRIPTION Material axes change flag for brick elements for quick changes EQ 1 0 default EQ 2 0 switch material axes a and b EQ 3 0 switch material axes a and c Coordinates of point p for AOPT 1 Components of vector a for AOPT 2 Components of vector v for AOPT 3 Components of vector d for AOPT 2 First material parameter Second material parameter Third material parameter Fourth material parameter LCMth material parameter LS DYNA3D Version 936 19 125 MAT MAT MAT BAMMAN This is Material Type 51 It allows the modeling of temperature and rate dependent plasticity with a fairly complex model that has many input parameters Bamman 1989 Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 Card 4 19 126 MAT LS DYNA3D Version 936 VARIABLE MID RO E PR
320. face with data Isotopic and anisotropic material models with failure can be handled Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Define the following two cards if and only if IORTHO 1 Card 3 Card 4 Variable LS DYNA3D Version 936 19 123 MAT MAT Define LMC material parameters using 8 parameters per card Card 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density MT User material type 41 50 inclusive A number between 41 and 50 has to be chosen LMC Length of material constant array which is equal to the number of material constants to be input NHV Number of history variables to be stored see Appendix A IORTHO Set to 1 if the material is orthotropic IBULK Address of bulk modulus in material constants array see Appendix A IG Address of shear modulus in material constants array see Appendix A IVECT Vectorization flag on 1 A vectorized user subroutine must be supplied IFAIL Failure flag on 1 Allows failure of the elements due to a material failure criterion AOPT Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location o
321. fficient than an iterative solver If convergence problems occur option 4 should be tried first before a direct solver is used 6 28 CONTROL LS DYNA3D Version 936 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 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 setto 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 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 LS DYNA3D Version 936 6 29 CONTROL CONTROL CONTROL TIMESTEP Purpose Set structural time step size control using different options Card Format Variable DTINIT TSSFAC ISDO TSLIMT DT2MS LCTM ERODE MSIST VARIABLE DESCRIPTION DTINIT Initial time step size EQ 0 0 LS DYNA3D determines initial ste
322. ffness form of type 3 Flanagan Belytschko In the shell elements IHQ lt 4 is the viscous form based on Belytschko Tsay If IHQ 4 or 5 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 the HOURGLASS Section LS DYNA3D Version 936 6 17 CONTROL CONTROL CONTROL OUTPUT Purpose Set output display parameters Card Format Variable NPOPT NEECHO NREFUP IACCOP OPIFS IPNINT IKEDIT NM Default VARIABLE DESCRIPTION NPOPT Print suppression during input phase flag for the printed output file EQ 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 EQ 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 NREFUP Flag to update reference node coordinates for beam elements This opti
323. file afile is optional and if given must be the name of an ASCII input file formatted in accordance with the VDA Surface Interface Definitions as defined by the German automobile and automotive supply industry bfile is required and is the name of a binary VDA file In a first run afile is given and bfile is created In any further run if the definitions have not changed afile can be dropped and only bfile is needed The purpose of bfile is that it allows for much faster initialization if the same VDA surfaces are to be used in a future LS DYNA3D run If afile is given bfile will always be created or overwritten The alias definitions are used for linking to LS DYNA3D and between the various surface definitions in the files defined by and bfile LS DYNA3D Version 936 1 1 Appendix I The alias definitions are of the form alias name ell el2 eln where name is any string of up to 12 characters and ell eln the names of VDA elements as specified in afile The list of elements can be empty in which case all the SURF and FACE VDA elements in afile will be used Care should be taken to ensure that the alias name is unique not only among the other aliases but among the VDA element names in afile This collection of VDA elements can later be indicated by the alias name In particular name may appear in later alias definitions Often it is required that a punch or die be created by a simple offset This can be achieved
324. file V vda It contains the following data file vdal vdal bin alias die sur0001 sur0003 offset fce0006 1 5 0 0 120 alias holderl sur008 file vda2 vda2 bin alias holder2 sur003 alias holder holderl holder2 ntrack 6 gap 0 5 end L4 LS DYNA3D Version 936 Explanation vdal alias die face alias holder1 vda2 alias holder2 alias holder ntrack 6 gap 0 5 end Appendix I This file contains the sufaces face elements sur0001 sur0003 fce0006 and sur0008 Combines the surface face elements sur0001 sur0003 and the offsetted surface fce0006 to a global surface Defines the surface face element sur0008 as holder1 This file contains the surface face element sur0003 Defines the surface face element sur0003 as holder2 Combines the surfaces holder and holder2 into a combined surface holder For each point the actual distances to 6 VDA surfaces are maintained Surface gaps of 0 5mm or less are filled Closes reading of this file LS DYNA3D Version 936 L5 Appendix J APPENDIX J LS TAURUS USER S MANUAL To open the LS TAURUS User s Manual select LS TAURUS in the Bookmark List which should be located at the left hand side of this window LS DYNA3D Version 936 J 1 LS DYNA3D RESULTS FROM VERSION 936 TIME COMPARISONS ON PC AND WORKSTATIONS CPU time in seconds element cycle time in microseconds time normalized to HP 735 PC 20 486DX4 100 Bar impac
325. fof fe fe fe lejal Default Card 2 3 4 etc Put one pair of points per 2E20 0 Input is terminated when a card is found 1 2 3 4 5 6 7 8 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 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 SFA Scale factor for abcissa value This is useful for simple modifications LS DYNA3D Version 936 9 7 DEFINE DEFINE VARIABLE DESCRIPTION SFO Scale factor for ordinate value function This is useful for simple modifications OFFA Offset for abcissa values see explanation below OFFO Offset for ordinate values function see explanation below DATTYP Data type Set to 1 for general xy data This affects how offsets are applied Al A2 Abcissa values Only pairs have to be defined see remarks below O1 O2 Ordinate function values Only pairs have to be defined see remarks below Warning In the definition of Load Curves used in the constitutive models reasonable spacing of the points should always be observed ie never set a single point off to a value approaching
326. force versus disp load curves NE 0 0 kinematic hardening without strain softening EQ 1 0 isotropic hardening without strain softening TYI Initial yield force in tension 0 CYI Initial yield force in compression 0 Load curve points are in the format displacement force or rotation moment The points must be in order starting with the most negative compressive displacement resp rotation and ending with the most positive tensile value The curves need not be symmetrical The displacement origin of the unloading curve is arbitrary since it will be shifted as necessary as the element extends and contracts On reverse yielding the loading curve will also be shifted along the displacement resp rotation axis The initial tensile and compressive yield forces TYI and CYI define a range within which the element remains elastic i e the loading curve is 19 222 MAT LS DYNA3D Version 936 MAT used for both loading and unloading If at any time the force in the element exceeds this range the element is deemed to have yielded and at all subsequent times the unloading curve is used for unloading LS DYNA3D Version 936 19 223 MAT MAT 20 force loading curve options force unloading curve isotropic hardening Bel kinematic hardening B lt 1 force Figure 19 25 General nonlinear material for discrete elements 19 224 MAT LS DYNA3D Version 936 MAT
327. g damper EQ 1 the material describes a torsional spring damper KD Dynamic magnification factor vo Test velocity CL Clearance FD Failure deflection twist for DRO 1 CDL Deflection twist for DRO 1 limit in compression see comment below TDL Deflection twist for DRO 1 limit in tension see comment below The constants from KD to TDL are optional and do not need to be defined 23 6 SECTION LS DYNA3D Version 936 SECTION If 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 V Faynamic 1 4 F static 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 kg 21 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 limi
328. h must be specified as negative values In tension the force and change in gauge length should be input as positive values The principal stretch ratio in the uniaxial direction is then given by Lot AL hy O with Lo being the initial length and L being the actual length Alternatively the stress versus strain curve can also be input by setting the gauge length thickness and width to unity 1 0 and defining the engineering strain in place of the change in gauge length and the nominal engineering stress in place of the force see Figure 19 9 The least square fit to the experimental data is performed during the initialization phase and is a comparison between the fit and the actual input is provided in the printed file It is a good idea to visually check to make sure it is acceptable The coefficients A and B are also printed in the output file It is also advised to use the material driver see Appendix H for checking out the material model 19 86 MAT LS DYNA3D Version 936 1 thickness EL TRE Figure 19 8 Uniaxial specimen for experimental data applied force initial area Ao change in gauge length _ AL gauge length EE Figure 19 9 The stress versus strain curve can used instead of the force versus the change in the gauge length by setting the gauge length thickness and width to unity 1 0 and defining the engineering strain in place of the change in gauge length and the nomina
329. hanges the Belytschko Tsay shell element Belytschko and Tsay 1981 and dynamic relaxation Also included were non 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 version included a cost effective resultant beam element a truss element a CO 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 tiebreak 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 In 1988 the author began working half time at LLNL to devote more time to the development and support of LS DYNA3D for automotive applications By the end of 1988 it was obvious that a much more concentrated effort would be required in the development of LS DYNA3D if problems in crashworthiness were to be properly solved therefore at the start of 1989 the author resigned from LLNL to continue code development full time at Livermore Software Technology Corporation The 1989 version introduced many enhanced capabilities including a one way treatment of slide surfaces with voids and friction cross sectional for
330. have significant penetrations see brickoff below are deleted from the contact interface Each processor creates a message file in its local directory which contains among other things a list of all nodes moved and those nodes deleted during this process The file name is given by appending a LS DYNA3D Version 936 L53 INTRODUCTION INTRODUCTION 4 digit processor number to the string MES so that for example the message file from processor 3 is MES0003 Default 4 bufnumsf n Sets the number of message buffers during contact equal to the number of the processors involved in the contact surface divided by n Larger values of n result in less memory being used but may negatively impact performance Default 2 bufsizesf n Sets the size of the contact message buffers equal to the maximum possible message size divided by n Larger values of n will result in messages being split into pieces when sent saving memory but possibly impacting performance Default 2 bigmem If this keyword appears it is equivalent to setting bufnumsf and bufsize both equal to 1 It requires the most memory but will guarantee the no contact related message ever gets split or ever has to wait for another message to complete before it can be sent Due to the message passing characteristics of IBM s SP2 and the large memory generally available bigmem is turned on for this machine by default and the other buffer related keywords are ignored Her
331. he concrete is defined with solid elements and the rebar with truss elements each with their own unique set of nodal points A string of nodes called slave nodes related to the truss elements may slide along a string of nodes 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 us SMAX e EXPP max where D is the damage parameter D D Au The shear force at time n is given as fa min fy GB 7 ERR ERR ds LS DYNA3D Version 936 5 27 CONTACT CONTROL CONTROL The keyword control cards are optional and can be used to change defaults however it is advisable to define the CONTROL TERMINATION card The keyword control cards in this section are defined in alphabetical order CONTROL ADAPTIVE CONTROL ALE CONTROL BULK VISCOSITY CONTROL CONTACT CONTROL COUPLING CONTROL CPU CONTROL DYNAMIC RELAXATION CONTROL ENERGY CONTROL HOURGLASS CONTROL OUTPUT CONTROL PARALLEL CONTROL SHELL CONTROL SOLUTION CONTROL STRUCTURED CONTROL SUBCYCLE CONTROL TERMINATION CONTROL THERMAL NONLINEAR CONTROL THERMAL SOLVER CONTROL THERMAL TIMESTEP CONTROL TIMESTEP The ordering of the control cards in the input file is competely arbitrary To avoid ambiguities define no more than one control card of each type
332. he local coordinate system defined for the rigid body in the definition of material model 20 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 The user subroutine is given below with all the necessary information contained in the comment cards SUBROUTINE AIRUSR RBU TIME DT1 DT2 PARAM HIST ITRNON RBUG RBVG RBAG Qe ke ee hee he e e e e he e he e e k e k k e k k k k ke k k k e k k ee e kkk kkk LIVERMORE SOFTWARE TECHNOLOGY CORPORATION LSTC Q COPYRIGHT 1987 1988 1989 JOHN HALLQUIST LSTC C ALL RIGHTS RESERVED Qe e ee he e he e e e e he e he e e k e k e he k he k e k se k k he k e k k k k he k k k k k k ke k he k k k k ke k ke k k k k k k k e e ke kkk USER SUBROUTINE TO INITIATE THE INFLATION OF THE AIRBAG VARIABLES DISPLACEMENTS ARE DEFINED AT TIME N 1 IN LOCAL SYSTEM VELOCITIES ARE DEFINED AT TIME N 1 2 IN LOCAL SYSTEM ACCELERATIONS ARE DEFINED AT TIME N IN LOCAL SYSTEM RBU 1 3 TOTAL DISPLACEMENTS IN THE LOCAL XYZ DIRECTIONS RBU 3 6 TOTAL ROTATIONS ABOUT THE LOCAL XYZ AXES RBV 1 3 VELOCITIES IN THE LOCAL XYZ DIRECTIONS RBV 3 6 ROTATIONAL VELOCITIES ABOUT THE LOCAL XYZ AXES RBA 1 3 ACCELERATIONS IN THE LOCAL XYZ DIRECTIONS RBA 3 6
333. he local t axis TDR Translational viscous damper about local r axis Optional TDS Translational viscous damper about local s axis Optional LS DYNA3D Version 936 19 165 MAT MAT VARIABLE DESCRIPTION TDT Translational viscous damper about local t axis Opitonal RDR Rotational viscous damper about the local r axis Optional RDS Rotational viscous damper about the local s axis Optional RDT Rotational viscous damper about the local t axis Optional The formulation of the discrete beam type 6 assumes that the beam is of zero length and requires no orientation node A small distance between the nodes joined by the beam is permitted The local coordinate system which determines r s t is given by the coordinate ID see DEFINE COORDINATE OPTION in the cross sectional input see SECTION BEAM where the global system is the default For null stiffness coefficients no forces corresponding to these null values will develop The viscous damping coefficients are optional 19 166 MAT LS DYNA3D Version 936 MAT MAT NONLINEAR ELASTIC DISCRETE BEAM This is Material Type 67 This material model is defined for simulating the effects of nonlinear elastic and nonlinear viscous zero length beams by using six springs each acting about one of the six local degrees of freedom Arbitrary curves to model transitional rotational stiffness and damping effects are allowed See notes below Card Format Card 1 1 2 3 4 5 6 7 8
334. he next card is encountered Card Format Type 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 DYNA3D Version 936 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 This input terminates when the next card is encountered See the PENCHK variable on the CONTACT definition Card Format Type 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 Card Format Type VARIABLE DESCRIPTION LCID Load curve ID LS DYNA3D Version 936 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 Al
335. her as a function of u or depending on the input variable FLAG as where EC is the ith coefficient and A linear least squares method is used to perform the fit LS DYNA3D Version 936 19 35 MAT MAT MAT ISOTROPIC ELASTIC PLASTIC This is Material Type 12 This is a very low cost isotropic plasticity model for three dimensional solids For shell elements a simple radial return is used and is not recommended due to lack of accuracy Card Format 1 2 3 4 5 6 7 8 el lehelelele VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus SIGY Yield stress ETAN Plastic hardening modulus BULK Bulk modulus K Here the pressure is integrated in time where j is the volumetric strain rate 19 36 MAT LS DYNA3D Version 936 MAT MAT ISOTROPIC ELASTIC FAILURE This is Material Type 13 This is a non iterative plasticity with simple plastic strain failure model Card Format Card 1 1 2 3 4 5 6 7 8 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density G Shear modulus SIGY Yield stress ETAN Plastic hardening modulus BULK Bulk modulus EPF Plastic failure strain PRF Failure pressure lt 0 0 LS DYNA3D Version 936 19 37 MAT MAT VARIABLE DESCRIPTION REM Element erosion option EQ 0 0 failed element eroded after failure NE 0 0 element is kept no removal exc
336. hieved which are very important in metalforming With smooth 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 LS DYNA3D Version 936 1 39 INTRODUCTION INTRODUCTION MESH GENERATION LS DYNA3D is designed to operate with a variety of commercial pre processing packages Currently direct support is available from 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 DYNA3D Some of the capabilities available in LS INGRID are Complete support for all control parameters loads and material types Mass property calculations Importing models from other sources PATRAN IDEAS IGES and NASTRAN formats Interactive viewing and graphical inspection of boundary conditions etc Model editing General purpose mesh generation Importing LS DYNA3D and DYNA3D models in a variety of 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
337. his input completely overides the existing termination conditions defined in the time zero run Termination by other means is controlled by the CONTROL TERMINATION control card For both options the input is identical Card Format Default LS DYNA3D Version 936 29 35 RESTART RESTART For the NODE option VARIABLE DESCRIPTION NID Node ID 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 For the BODY option VARIABLE DESCRIPTION PID Part ID of rigid body 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 29 36 RESTART LS DYNA3D Version 936 RESTART TITLE Purpose Define job title Card Format 1 2 3 4 5 6 7 8 Variable TITLE Default LS DYNA3D USER INPUT VARIABLE DESCRIPTION TITLE Heading to appear on output LS DYNA3D Version 936 29 37 RESTART REFERENCES REFERENCES Allman D J A Compatible Triangular Element Including Vertex Rotations for Plane Elasticity A
338. i p epa edt 11 17 ELEMENT_SEATBELT_SLIPRING eterne erede 11 21 EEEMENT SHEEL OPTION tre eer ire rete Eee rh ipte SU Piste vea dg 11 23 ELEMENT SOLID OPTION ett ertet ete ette ete eee aa 11 28 BEEMENLT TSHELL 11 33 ROS PE E 12 1 EOS LINEAR POLYNOMIAE 12 2 E E ERAN ERE E SERES 12 4 BOSSSACK TUESDAY eic ett tete ete eet e t er e e e eee ae ek De e INE E 12 5 BOS GRUNBISEN 5 2p Pepper repr e hd 12 6 EOS RATIO OE POEYNOMIAPES mrt eere eere ere ee 12 8 EOS LINEAR POLYNOMIAL WITH ENERGY LEAK eem 12 12 EOS IGNITION AND GROWTH OF REACTION IN HE 12 13 EOS TABULATED COMPACTION re ee e spere tee p reip detis 12 16 BOS TABULATED eS RREUSNEEBRDISRIUEBI IQQ URIQEP inane 12 19 EOS PROPELLANT DEFLAGRATION 12 21 EOS TENSOR PORE COLLAPSE eere nen en nennen nennen hene eene nennen 12 26 UOUnnUT 13 1 HOURJGIEASS ei ate e a oer MAU THER 13 1 iv LS DYNA3D Version 936 TABLE OF CONTENTS
339. ian Hydrocode Technology J Comp Meths Appl Mechs Eng 30 1982 Hallquist J O Preliminary User s Manuals for DYNA3D and DYNAP Nonlinear Dynamic Analysis of Solids in Three Dimension University of California Lawrence Livermore National Laboratory Rept UCID 17268 1976 and Rev 1 1979 a Hallquist J O A Procedure for the Solution of Finite Deformation Contact Impact Problems by the Finite Element Method University of California Lawrence Livermore National Laboratory Rept UCRL 52066 1976 Hallquist J O A Numerical Procedure for Three Dimensional Impact Problems American Society of Civil Engineering Preprint 2956 1977 Hallquist J O A Numerical Treatment of Sliding Interfaces and Impact in K C Park and D K Gartling eds Computational Techniques for Interface Problems AMD Vol 30 ASME New York 1978 Hallquist J O NIKE2D An Implicit Finite Element Code for Analyzing the Static and Dynamic Response of Two Dimensional Solids University of California Lawrence Livermore National Laboratory Rept UCRL 52678 1979 b Hallquist J O User s Manual for DYNA2D An Explicit Two Dimensional Hydrodynamic Finite Element Code with Interactive Rezoning University of California Lawrence Livermore National Laboratory Rept UCID 18756 1980 Hallquist J O User s Manual for DYNA3D and DYNAP Nonlinear Dynamic Analysis of Solids in Three Dimensions University of California La
340. ic behavior is modelled using force moment curves versus displacements rotation Optionally failure can be specified based on a force moment criterion and a displacement rotation criterion See also notes below Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 LS DYNA3D Version 936 19 169 MAT MAT Card 4 1 2 4 5 6 7 8 FFAILR FFAILS FFAILT MFAILR MFAILS MFAILT 5 UFAILR UFAILS oo oo VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density see also volume on SECTION_BEAM definition TKR Translational stiffness about local r axis TKS Translational stiffness about local s axis TKT Translational stiffness about local t axis RKR Rotational stiffness about the local r axis RKS Rotational stiffness about the local s axis RKT Rotational stiffness about the local t axis TDR Translational viscous damper about local r axis TDS Translational viscous damper about local s axis TDT Translational viscous damper about local t axis RDR Rotational viscous damper about the local r axis 19 170 MAT LS DYNA3D Version 936 VARIABLE RDS RDT LCPDR LCPDS LCPDT LCPMR LCPMS LCPMT FFAILR FFAILS FFAILT MFAILR MFAILS MFAILT UFAILR UFAILS UFAILT TFAILR TFAILS LS DYNA3D Version 936 MAT DESCRIPTION Rotational viscous damper about the local s axis Rotational viscous damper about the local
341. ic force strain input characteristics and loading rates does not significantly alter the overall forces strain performance The damping forced opposes the relative motion of the nodes and is limited by stability D 1x mass x relative velocity time step size In addition the magnitude of the damping force is limited to one tenth of the force calculated from the force strain relationship and is zero when the belt is slack Damping forces are not applied to elements attached to sliprings and retractors The user inputs a mass per unit length that is used to calculate nodal masses on initialization A minimum length is also input This controls the shortest length allowed in any element and determines when an element passes through sliprings or are absorbed into the retractors One tenth of a typical initial element length is usually a good choice LS DYNA3D Version 936 19 229 MAT MAT MAT THERMAL OPTION The MAT THERMAL cards allow thermal properties to be defined in coupled structural thermal and thermal only analyses see CONTROL SOLUTION Thermal properties must be defined for all solid and shell elements in such analyses Thermal properties need not be defined for beam or discrete elements as these elements are not accounted for in the thermal phase of the calculation However dummy thermal properties will be echoed for these elements in the D3HSP file Thermal material properties are specified by a thermal material ID nu
342. ients define only one if not varying with temperature Corresponding Young s moduli coefficients define only one if not varying with temperature Corresponding thermal expansion coefficients 19 151 MAT MAT This material model was developed to simulate forming of glass products e g car windshields at high temperatures Deformation is by viscous flow but elastic deformations can also be large The material model in which the viscosity may vary with temperature is suitable for treating a wide range of viscous flow problems and is implemented for brick and shell elements Volumetric behavior is treated as linear elastic The deviatoric strain rate is considered to be the sum of elastic and viscous strain rates Oo g E 4 total elastic viscous 26 2v where G is the elastic shear modulus v is the viscosity coefficient and indicates a tensor The stress increment over one timestep dt is do 2Ge at Cato E total 9 The stress before update is used for 6 For shell elements through thickness strain rate is calculated as follows G do33 0 224 230 2G 33 dt 1633 9 where the subscript ij 33 denotes the through thickness direction and is the elastic bulk modulus This leads to 33 a fens ens bp a K 46 3 i 3 G in which p is the pressure defined as the negative of the hydrostatic stress The variation
343. ies This creates both an opportunity and a difficulty LSDYNA3D has many ways approximating different aspects of problems but they are frequently not obvious to users without considerable experience Therefore in this Appendix we emphasize modeling methods rather than simply listing capabilities THE LS DYNA3D OCCUPANT SIMULATION PROGRAM LINK Coupling between the OSP and LS DYNA3D is performed by combining the programs into a single executable In the case of CAL3D LS DYNA3D calls CAL3D as a subroutine but in the case of MADYMO LS DYNAOD is called as a subroutine The two programs are then integrated in parallel with the results being passed between the two until a user defined termination time is reached The OSP and LS DYNA3D have different approaches to the time integration schemes The OSP time integrators are based on accurate implicit integrators which are valid for large time steps which are on the order of a millisecond for the particular applications of interest here An iterative solution is used to insure that the problem remains in equilibrium The implicit integrators are LS DYNA3D Version 936 F 1 Appendix F extremely good for smoothly varying loads however sharp nonlinear pulses can introduce considerable error An automatic time step size control which decreases the time step size quickly restores the accuracy for such events The LS DYNA3D time integrator is based on an explicit central difference scheme Stability requ
344. igns For this reason a more accurate modeling of the compliance of the knee bolster and the knee is required The knee can be modeled as a combined rigid deformable body The rigid body is coupled to the OSP Overlaying the rigid body are brick elements which model the skin that exists over the knees of the dummy These brick elements use material type 6 VISCOELASTIC which is a viscoelastic model that does a reasonable job of approximating the hysteretic behavior of rubbers The inner layer of the brick elements is attached to the rigid body through the CONSTRAINED EXTRA NODES Option Between the knee bolster is a SURFACE TO SURFACE contact definition COMMON ERRORS L Improper airbag inflation or no inflation The most common problem is inconsistency in the units used for the input constants An inflation load curve must also be specified The normals for the airbag segments must all be consistent and facing outwards If a negative volume results this can sometimes be quickly cured by using the flip flag on the control volume definition to force inward facing normals to face outwards 2 Excessive airbag distortions Check the material constants Triangular elements should have less distortion problems than quadrilaterals Overlapped elements at time zero can cause locking to occur in the contact leading to excessive distortions The considerable energy input to the bag will create numerical noise and some damping
345. ile The following card is left blank for this option 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 D3DUMPO01 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 to create too many The D3PLOT 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 TAURUS 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 TAURUS in Phase 2 The default names for the D3PLOT D3DRLF and the D3THDT files are D3PLOT 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 genera
346. iles 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 LS DYNA3D Version 936 1 31 INTRODUCTION INTRODUCTION PRECISION The explicit time integration algorithms used in LS DYNA3D 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 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 DYNA3D have to be aware of potential problems A major reorganization of LS DYNA3D 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 DYNA3D to take advantage of the 64 bit technology offered by some computer manufacturers 1 32 INTRODUCTION LS
347. in the vda files in two ways either on VDA elements directly or on parts defined by aliases This feature offers great capability in generating and using surface data information Offset version 1 As an option the keyword offset may appear in the alias list which allows a new surface to be created as a normal offset plus translation of a VDA element in the file The keyword offset my be applied to VDA elements only not aliases The usage of offset follows the form offset elem normal x y z where normal is the amount to offset the surface along the normal direction and x y z are the translations to be applied The default normal direction is given by the cross product of the local u and v directions on the VDA surface taken in that order normal can be negative Offset version 2 Frequently it is convenient to create a new alias name by offsetting and translating an existing name The keyword goffset provides this funtion goffset alias name X yc zc normal x y z previous alias name where normal x y and z are defined as in the offset keyword A reference point xc yc and zc defines a point in space which determines the normal direction to the VDA surface which is a vector from the origin to 2 See example below L2 LS DYNA3D Version 936 offset 10 5 0 0 0 1 0 Z ps element 10 Appendix I offset alias die 1 0 2 0 1 0 5 0 0 0 1 0 previous alias dieold um dieold Fi
348. increasing y Not all five points need be to be defined This curves applies at the reference pressure at other pressures the curve varies according to ag aj and a2 as in the soil and crushable foam model Material 5 SOIL AND FOAM The elastic moduli G and K are pressure sensitive b G Go p B Po b where and the input values p is the current pressure po the cut off or reference pressure must be zero or negative If p attempts to fall below 1 more tensile the shear stresses set to zero and the pressure is set to po Thus the material has no stiffness or strength in tension The pressure in compression is calculated as follows Ko where V is the relative volume 1 the ratio between the original and current volume LS DYNA3D Version 936 19 203 MAT MAT MAT PLASTICITY WITH DAMAGE This is Material Type 81 An elasto plastic material with an arbitrary stress versus strain curve and arbitrary strain rate dependency can be defined Damage is considered before rupture occurs Also failure based on a plastic strain or a minimum time step size can be defined Card Format Card 1 1 2 3 4 5 6 8 7 Card 2 Card 3 19 204 LS DYNA3D Version 936 MAT Card 4 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio
349. ing 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 11 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 T and where T is LS DYNA3D Version 936 11 21 ELEMENT ELEMENT on the high tension side and is the force on the low tension side Thus if T2 is sufficiently close to no slip occurs otherwise slip is just sufficient to reduce the ratio T2 UT 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 If due to slip through the slipring the unstretched length of 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 11 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
350. ing rotation is not considered in the failure calculation Optional failure parameter If zero the corresponding rotation is not considered in the failure calculation 19 171 MAT MAT VARIABLE DESCRIPTION TFAILT Optional failure parameter If zero the corresponding rotation Or is not considered in the failure calculation For the translational and rotational degrees of freedom where elastic behavior is desired set the load curve ID to zero The formulation of the discrete beam type 6 assumes that the beam is of zero length and requires no orientation node A small distance between the nodes joined by the beam is permitted The local coordinate system which determines r s t is given by the coordinate ID see DEFINE COORDINATE OPTION in the cross sectional input see BEAM where the global system is the default gt PLASTIC DISPLACEMENT Figure 19 15 The resultant forces and moments are limited by the yield definition The initial yield point corresponds to a plastic displacement of zero Catastrophic failure based on force resultants occurs if the following inequality is satisfied 2 2 2 2 m 2 2 d ii E x Y Tail T jai F Fs Mj 19 172 MAT LS DYNA3D Version 936 MAT After failure the discrete element is deleted Likewise catastrophic failure based on displacement resultants occurs if the following inequality is satisfied
351. ion 936 VARIABLE PSIDMX PSIDMN LCVMNX DIR VID TB TD CONSTRAINED DESCRIPTION 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 part attribute the closure distance D and D in Figure 4 9 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 4 9 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
352. ion of LS DYNA3D 936 has a much improved user s manual plus many new capabilities including Belyschko Leviathan quadrilateral shell element Automatic rigid to deformable switching e Damage based plasticity Trim curves for metal forming springback Multi chambered airbags and bag to bag venting e Local coordinate systems for cross section output e Stress initialization for beams shell and solid elements More user control for hourglass control constants Table definitions for strain rate effects LS DYNA3D Version 936 INTRODUCTION INTRODUCTION e Coupling with Madymo version 5 1 general linear viscoelasticity Ogden rubber model e Least squares fit for viscoelastic material constants e Implicit heat transfer Also the error checking in LS DYNA3D has been substantially improved to find input errors before execution begins 1 2 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION INTRODUCTION CHRONOLOGICAL HISTORY DYNA3D Hallquist 1976 was originated in 1976 at the Lawrence Livermore National Laboratory The early applications were primarily related to the low velocity impact of heavy solid structures These applications tended to be time consuming and potential users were discouraged by the potentially long run times Part of the problem of course was related to the rather inefficient implementation of the element technology which was further aggravated by the fact that the super
353. ions are attached to solid elements using the eulerian 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 2 6 7 8 Variable Default For the SEGMENT option define the following card Card Format Card 1 1 2 3 4 5 6 7 8 Variable Default 3 12 BOUNDARY LS DYNA3D Version 936 BOUNDARY VARIABLE DESCRIPTION SSID Segment set ID N1 N2 Node ID s defining segment LS DYNA3D Version 936 3 13 BOUNDARY 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 For the SET option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 2 6 7 8 Variable Default For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 Variable Default 3 14 BOUNDARY LS DYNA3D Version 936 BOUNDARY Define the following card for both options Card Format Card 2 of 2 Default VARIABLE DESCRIPTION SSID Segment set ID see SET SEGMENT N1 N2 Node ID s defining segment RFLCID Load curve ID for radiation factor f see DEFINE_CURVE GT 0 function versus time EQ 0 use constant multiplier value FMULT LT 0 function versus temperature RFMULT Curve m
354. ired for all WANG NEFSKE models Card 1 1 2 3 4 5 6 7 8 Card 2 1 2 3 4 5 6 7 8 LCCP23 AP23 LCAP23 Card 3 1 2 3 4 5 6 7 8 1 8 AIRBAG LS DYNA3D Version 936 AIRBAG If the inflator is modeled LCMT 0 define the following card If not define but leave blank Card 4 1 VARIABLE DESCRIPTION CV Heat capacity at constant volume CP Heat capacity at constant pressure T Temperature of input gas For temperature variations a load curve LCT may be defined LCT Optional load curve number defining temperature of input gas versus time This overides columns T LCMT 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 6 TVOL Tank volume which is required only for the tank pressure versus time curve LCMT C23 Vent orifice coefficient which applies to exit hole Set to zero if LCC23 is defined below LCC23 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 A23 Vent orifice area which applies to exit hole Set to zero if LCA23 is defined below LCA23 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 CP23 Orifice coefficient for leakage fabric porosity Se
355. ires that the time step size be less than the highest frequency in the system For a coarse airbag mesh this number is on the order of 100 microseconds while an actual car crash simulation is on the order of 1 microsecond The smallest LS DYNA3D models have at least 1 000 elements Experience indicates that the cost of a single LS DYNA3D time step for a small model is at least as great as the cost of a time step in the OSP Therefore in the coupling the LS DYNA3D time step is used to control the entire simulation including the OSP part This approach has negligible cost penalties and avoids questions of stability and accuracy that would result by using a subcycling scheme between the two programs Optionally a subcycling scheme can be used however the results of the analysis have to be checked with care LS DYNA3D has a highly developed rigid body capability which is used in different parts of automobile crash simulation In particular components such as the engine are routinely modeled with rigid bodies These rigid bodies have been modified so that they form the basis of the coupling procedure in LS DYNA3D to the OSP In LS DYNA3D the geometry of a model is broken down into nodal points which identify positions in space These nodes are then connected by elements so that the volume of a structure is identified Each element has a material associated with it If the element is deformable then the material will specify its characteristics such
356. 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 A new shell has been recently published by Belytschko Wong and Chiang Belytschko Wong and Chang 1989 1992 in which inexpensive modifications were proposed 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 available in LS DYNA3D Also two shell elements which use full integration are available in LS DYNA3D but are rather expensive Three dimensional plane stress constitutive subroutines are implemented for the shell elements which iteratively updates 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 solid 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
357. is included in the strain energy functional which is function of the relative volume J Ogden 1984 Wi J2 J Y C5 41 3 45 3 Wa J 4 0 4 250 3 Jy LJ In order to prevent volumetric work from contributing to the hydrostatic work the first and second invarients are modified as shown This procedure is described in more detail by Sussman and Bathe 1987 Rate effects are taken into account through linear viscoelasticity by a convolution integral of the form t eiii t 2 E d or in terms of the second Piola Kirchhoff stress S ij and Green s strain tensor Ej t Sij where 6 1 1 and t are the relaxation functions for the different stress measures This stress is addedto the stress tensor determined from the strain energy functional If we wish to include only simple rate effects the relaxation function is represented by six terms from the Prony series N 8 0 m 1 given by gt y Pi i l 19 192 MAT LS DYNA3D Version 936 MAT This model is effectively a Maxwell fluid which consists of a dampers and springs in series We characterize this in the input by shear modulii G and decay constants B The viscoelastic behavior is optional and an arbitrary number of terms may be used The Mooney Rivlin rubber model model 27 is obtained by specifying n 1 In spite of the differences in formulation
358. is measured Rather B will be measured relative to the computed offset LS DYNA3D Version 936 4 21 CONSTRAINED CONSTRAINED CONSTRAINED LINEAR Purpose Define linear constraint equations between displacements rotations which can be defined in local global coordinate systems Card Formats Card 1 2 3 4 5 6 7 8 Define NUM cards below card for each nodal point Card 2 5 6 7 8 EIL VARIABLE DESCRIPTION NUM Number of nodes in equation NID Node ID DOFX Insert 1 0 for no translational constraint in local x direction DOFY Insert 1 0 for no translational constraint in local y direction 4 22 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED VARIABLE DESCRIPTION DOFZ Insert 1 0 for no translational constraint in local z direction DOFRX Insert 1 0 for no rotational constraint about local x axis DOFRY Insert 1 0 for no rotational constraint about local y axis DOFRZ Insert 1 0 for no rotational constraint about local z axis COEF Nonzero coefficient In this section linear constraint equations of the form n Cus Co k l can be defined where are the displacements and Cx are user defined coefficients Unless LS DYNA3D 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
359. is model is described in detail by Chung and Shah 1992 and is used here It is based on a six parameter model which is ideally suited for 3D continuum problems see notes below For sheet forming problems material 35 based on a 3 parameter model is recommended Card Format Card 1 1 2 3 4 5 6 7 8 pe tm fe fe fw Card 2 efe eee 3 Card 4 foe fw e ow fe fm me fe fe fet et ef ef LS DYNA3D Version 936 19 101 MAT MAT Card 5 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus E PR Poisson s ratio v K k strength coefficient see notes below EO 0 strain corresponding to the initial yield see notes below N n hardening exponent for yield strength M m flow potential exponent in Barlat s Model A a anisotropy coefficient in Barlat s Model B b anisotropy coefficient in Barlat s Model C c anisotropy coefficient in Barlat s Model F f anisotropy coefficient in Barlat s Model G g anisotropy coefficient in Barlat s Model H h anisotropy coefficient in Barlat s Model AOPT Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES 19 102 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTIO
360. is the tail of the normal vector is the corner point of the finite size plane Card 3 1 2 3 4 XHEV YHEV ZHEV LENL LENM 6 m felefele Card Format 3 of 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 7 8 direction negative to n see Figure 22 1 Card 3 1 2 3 4 7 e pe oo TENEO LS DYNA3D Version 936 22 3 RIGIDWALL 8 RIGIDWALL Card Format 3 of 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 to n see Figure 22 1 Card 3 1 2 3 4 5 6 7 8 Card Format 3 of 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 Default Variable Default 22 4 RIGIDWALL LS DYNA3D Version 936 VARIABLE NSID NSIDEX BOXID XT YT ZT ZH FRIC XHEV YHEV ZHEV LENL LENM LENP RADCYL LENCYL RADSPH LCID OPT LS DYNA3D Version 936 RIGIDWALL DESCRIPTION Nodal set ID containing slave nodes see SET NODE OPTION EQ 0 all nodes are slave to rigid wall Nodal set ID containing nodes that exempted as slave nodes see SET_ NODE OPTION If defined only nodes in box are included as slave nodes to rigid wall x coordinate of
361. iscrete beam which have six degrees of freedom This lumped inertia is partitioned to the two nodes of the beam element Coordinate system ID for orientation materials type ID 67 69 see COORDINATE_SYSTEM This is not defined for cable elements Cable area materials type ID 71 MAT_CABLE Offset for cable MAT CABLE For a definition see materials type ID 71 1 For the truss element define the cross sectional area A only LS DYNA3D Version 936 23 4 SECTION SECTION ltt Iss J EE ij _ 10 2155 55 A znr Lem 166 9770 J 32nr h ft 7 fss7 2 32nrh Ig Ce A htw 3btp p 242 Qi 2b h twtr Pls t A _ bh rer ar ET lit 2 5 2 b ty te _ beh ___ ___ las 12 55 xh t tw J 2 21 0 f 0 12h _ _6 fit 155 A bh Shear Area Figure 23 1 Properties of beam cross section for several common cross sections LS DYNA3D Version 936 23 5 SECTION SECTION SECTION DISCRETE Purpose Defined spring and damper elements for translation and rotations See also explanation below The definitions below have to correspond with the material type selection for the elements Card Format Card 1 1 2 3 4 5 6 7 8 Card 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 EQ 0 the material describes a translational sprin
362. itional values may be defined Pressures corresponding to volumetric strain values LS DYNA3D Version 936 MAT Pressure is positive in compression Volumetric strain is given by the natural log of the relative volume and is negative in compression Relative volume is ratio of the current volume to the initial volume at the start of the calculation The tabulated data should be given in order of increasing compression If the pressure drops below the cutoff value specified it is reset to that value Fora detailed description we refer to Kreig 1972 Figure 19 3 Pressure versus volumetric strain curve for soil and crushable foam model The volumetric strain is given by the natural logarithm of the relative volume V LS DYNA3D Version 936 19 21 MAT MAT The deviatoric perfectly plastic yield function is described in terms of the second invariant J2 J pisi pressure p and constants aj and a as 2 J5 ag a p a5p 1 3 On the yield surface 02 where Gy is the uniaxial yield stress 1 3 3 a9 taptap There is no strain hardening on this surface For no pressure hardening aj 0 and 3aq 2 defines the yield strength 19 22 MAT LS DYNA3D Version 936 MAT MAT VISCOELASTIC This is Material Type 6 This model allows the modeling of viscoelastic behavior for beams Hughes Liu shells and solids Also see MAT GENERAL VISCOELASTIC for a mor
363. iven by min Mrupper Mrcurve and similar for s and t where current plastic moment Mrcurve moment taken from load curve at the current rotation scaled according to the scale factor LS DYNA3D Version 936 19 93 MAT MAT The effect of this is to provide an upper limit to the moment that can be generated it represents the softening effect of local buckling at a hinge site Thus if a member is bent about is local s axis it will then be weaker in torsion and about its local t axis For moments softening curves the effect is to trim off the initial peak although if the curves subsequently harden the final hardening will also be trimmed off It is not possible to make the plastic moment vary with axial load axial force strains or change in length see AOPT Figure 19 10 force magnitude is limited by the applied end moment For an intermediate value of the end moment LS DYNA3D interpolates between the curves to determine the allowable force value 19 94 MAT LS DYNA3D Version 936 MAT MAT CLOSED FORM SHELL PLASTICITY This is Material Type 30 With this model a non iterative exact treatment of the plane stress constitutive equations for elasto plastic material can be defined This model is in general more efficient than a fully iterative treatment However on vector computers the vectorized form 1 using only 3 iterations as optionally available in material type 3 is far more efficien
364. jet vector head to defined code centerline ZJVH z coordinate of jet vector head to defined code centerline LS DYNA3D Version 936 1 13 AIRBAG AIRBAG VARIABLE DESCRIPTION CA Cone angle 0 defined in radians LCRJV 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 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 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 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 Remark 1 It is assumed that the jet direction is defined by the coordinate method XJFP YJFP ZJFP
365. l DIF mat 1 for all value Set distance of model from viewer DIST value in normalized model dimensions Delete display of material in subsequent views DMAT ALL or list of numbers Display outside edges of model Scale current displacement from initial shape After using TAURUS command will reset display to read current DYNA3D state data Set or unset element numbering in subsequent views Delete display and return to execution Escapes from menu pad mode Return to execution and keep display active Fix or unfix current contour levels Set display field of view angle FOV value in degrees View with colored contour fringes fringe component gt list mat gt see TAURUS manual Display a saved frame GETF frame gt LS DYNA3D Version 936 HARDWARE HELP HZB LIMIT MAT MENU MOTION MOV NDPLT NOFRAME PAUSE PHS2 or THISTORY PICK POST LS DYNA3D Version 936 Appendix G Hardware mode workstation hardware calls are used to draw move and color model repeat command to reset to normal mode Switch on or off hardware zbuffer for a subsequent view draw or contour command rotations and translations will be in hardware Set range of node numbers subsequent views limit first node gt last node gt Re enable display of deleted materials mat lt all or list of numbers gt Button menu pad mode Motion of model through mouse move
366. l engineering stress in place of the force LS DYNA3D Version 936 19 87 MAT MAT MAT RESULTANT PLASTICITY This is Material Type 28 A resultant formulation for beam and shell elements including elasto plastic behavior can be defined This model is available for the Belytschko Schwer beam the C9 triangular shell and the Belytschko Tsay shell For beams the treatment is elastic perfectly plastic but for shell elements isotropic hardening is approximately modeled For a detailed description we refer to the Theoretical Manual Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic hardening modulus for shells only 19 88 MAT LS DYNA3D Version 936 MAT MAT FORCE LIMITED This is Material Type 29 With this material model for the Belytschko Schwer beam only plastic hinge forming at the ends of a beam can be modeled using curve definitions Optionally collapse can also be modelled Description FORCE LIMITED Resultant Formulation Card Format Card 1 1 2 3 4 5 6 7 8 E Card 2 ES 7 Card 3 i i LS DYNA3D Version 936 19 89 MAT MAT Card 4 eI Card 5 EN eI Card 6 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus PR
367. l surfaces CAL3D input file Number of words to be allocated On engineering workstations a word is usually 32bits In order to avoid undesirable results each LS DYNA3D run should be performed in a separate directory Also files should be removed or renamed to avoid confusion 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 LS DYNA3D Version 936 1 33 INTRODUCTION INTRODUCTION File Organization stress initialization printer file O d3hsp messag input echo E ASCII Database Figure I 3 1 34 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION If the word MEMORY is found anywhere the execution line and if it is not set via nwds LS DYNA3D will give the default size of memory 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 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 th
368. lculation 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 The temperature is defined as T Tbase Tscale f t where f t is the current value of the loadcurve Tscale is the scaled temperature Tbase is the base temperature 18 30 LOAD LS DYNA3D Version 936 MAT MAT LS DYNA3D has historically referenced materials by type identifiers Below these identifiers are given with the corresponding keyword name The numbers in brackets identify the element formulations for which the material model is implemented 0 Solids 1H Hughes Liu beam 1B Belytschko resultant beam Belytschko integrated solid and tubular beams Truss 1D Discrete beam 2 Shells 3 Thick shells 4 Special airbag element TYPE 1 MAT_ELASTIC 0 1H 1B 1I 1T 2 3 TYPE 2 MAT_ORTHOTROPIC_ELASTIC 0 2 3 TYPE 3 MAT_PLASTIC_KINEMATIC 0 1H 1I 1T 2 3 TYPE 4 MAT_ELASTIC_PLASTIC_THERMAL 0 2 3 TYPE 5 MAT_SOIL_AND_FOAM 0 TYPE 6 MAT_VISCOELASTIC 0 1H TYPE 7 MAT_BLATZ KO_RUBBER 0 2 TYPE 8 M
369. ld strength of the material is Oy k c e where is the strain corresponding to the initial yield stress and is the plastic strain LS DYNA3D Version 936 19 103 MAT MAT MAT FABRIC This is Material Type 34 This material is especially developed for airbag materials The fabric model is a variation on the layered orthotropic composite model of material 22 and is valid for 3 and 4 node membrane elements only In addition to being a constitutive model this model also invokes a special membrane element formulation which is more suited to the deformation experienced by fabrics under large deformation For thin fabrics buckling can result in an inability to support compressive stresses thus a flag is included for this option A linearly elastic liner is also included which can be used to reduce the tendency for these elements to be crushed when the no compression option is invoked In LS DYNA3D versions after 931 the isotropic elastic option is available Card Format Card 1 1 2 3 4 5 Card 2 Card 3 vine 19 104 LS DYNA3D Version 936 Card 4 MAT Card 5 VARIABLE MID RO EA EB EC PRBA PRCA PRCB GAB GBC GCA DESCRIPTION Material identification A unique number has to be chosen Mass density Young s modulus longitudinal direction For an isotopic elastic fabric material only EA and PRBA are defined and are used as
370. lded 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 where the choice of X may coincide with the folded or unfold configurations It is this unfolded configuration which may be specified here Card Format 18 3 16 0 Card 1 1 2 3 4 5 6 7 8 9 10 VARIABLE DESCRIPTION NID Node number X coordinate Y y coordinate Z 7 coordinate 1 20 AIRBAG LS DYNA3D Version 936 ALE ALE The keyword ALE provides a way of defining options that are specific to the keyword capability 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 Default VARIABLE DESCRIPTION SNID Slave node ID see Figure 2 1 MNIDI First master node ID MNID2 Second master node ID Abritrary Lagrangean Eulerian meshes are defined via the choice of the element type only solids elements can be used and the CONTROL card LS DYNA3D Version 936 2 1 ALE ALE 1st master node slave node 2nd master node Figure 2 1 X This simple constraint which ensures that a slave node remains on a straight line betwee
371. le and logically organized data input scheme We believe this reorganization will ultimately reduce the time required to understand the input since it eliminates much of confusion of past versions by combining similar functions together under the same keyword For example under the keyword ELEMENT we not only include solid beam and shell elements but also spring elements discrete dampers seat belts and lumped masses In Version 92X these elements were specified in separate and disjoint sections of the user s manual Materials and contact algorithms are specified by names and not by type numbers making the data more readable by those less familiar with the program Material properties for all elements are defined in one section under the keyword MAT thereby eliminating three separate sections of material input required by Version 92X No ordering of the input is expected or required Either formatted or unformated input may be used with commas serving as delimiters in the latter case Although the implementation of keyword input meant the complete restructuring of the input phase we have kept the option of reading the input data prepared for earlier versions of LS DYNA3D to make the transition in the translators from the structured input file to the keyword file as simple and painless as possible New capabilities in Version 93X are supported in the structured file so that existing translators to Version 92X can be quickly updated This latest revis
372. lements with LS DYNA3D Version 936 1 23 INTRODUCTION INTRODUCTION 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 used 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 brick shell or solid 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 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 1 24 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION SLIDING
373. locity However if the nodal velocity is also specified on a INITIAL_VELOCITY_ NODE card then the velocity specification on this card will be used LS DYNA3D Version 936 15 13 INITIAL INITIAL INITIAL VELOCITY NODE Purpose Define initial nodal point velocities for a node Card Format 1 2 3 4 5 6 7 8 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 15 14 INITIAL LS DYNA3D Version 936 INITIAL INITIAL VELOCITY GENERATION Purpose Define initial velocities for rotating and translating bodies Card Format Card 1 1 2 3 4 5 6 7 8 Variable Default Card 2 1 2 3 4 5 6 7 8 Variable Default VARIABLE DESCRIPTION SID 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 DYNA3D Version 936 15 15 INITIAL INITIAL VARIABLE XC YC ZC
374. ls for dynamic relaxation 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 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 EQ 0 not active EQ 1 dynamic relaxation is activated LS DYNA3D Version 936 29 17 RESTART RESTART Remark 1 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 DYNA3D continues the output of data as it would without the dynamic relaxation being
375. lue 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 Shell thickness changes considered in single surface contact EQ 1 no consideration default EQ 2 shell thickness changes are included 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 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 LS DYNA3D Version 936 VARIABLE USRFRC NSBCS INTERM XPENE SSTHK ECDT TIEDPRJ CONTROL DESCRIPTION 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 Number
376. mal recovery and rg T and Rg T are the functions describing dynamic recovery If we assume that WP 0 we recover the Jaumann stress rate which results in the prediction of an oscillatory shear stress response in simple shear when coupled with a Prager kinematic hardening assumption Johnson and Bammann 1984 Alternatively we can choose RTUU R which recovers the Green Naghdi rate of Cauchy stress and has been shown to be equivalent to Mandel s isoclinic state Bammann and Aifantis 1987 The model employing this rate allows a reasonable prediction of directional softening for some materials but in general under predicts the softening and does not accurately predict the axial stresses which occur in the torsion of the thin walled tube The final equation necessary to complete our description of high strain rate deformation is one which allows us to compute the temperature change during the deformation In the absence of a coupled thermo mechanical finite element code we assume adiabatic temperature change and follow the empirical assumption that 90 95 of the plastic work is dissipated as heat Hence T 9 c p 4 pc where p is the density of the material and C the specific heat In terms of the input parameters the functions defined above become 2 9 10 C3 exp C4 T Cllexp C12 T C5 6 C13exp C14 T C7 exp C8 T 15 16 17 18 19 130
377. mass unit x 1 acceleration unit 1 length unit time unit and that 1 acceleration unit Examples of sets of consistent units are Length unit Time unit Mass unit Force unit meter second kilogram Newton millimeter second tonne Newton 210 0E 03 millimeter millisecond kilogram kiloNewton 210 0 Young s Modulus of Steel 210 0E 09 Density of Steel 7 85E403 7 85E 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 81 E 03 Velocity equivalent to 30 mph 13 4 13 4E 03 13 4 LS DYNA3D Version 936 L45 INTRODUCTION INTRODUCTION 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 The type is the variable type and is either F for floating point or I for an integer The default gives the value set if 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 equiv
378. mber TMID this number is independent of the material ID number MID defined on all other MAT property cards In the same analysis identical TMID and MID numbers may exist The TMID and MID numbers are related through the PART card 19 230 MAT LS DYNA3D Version 936 MAT MAT THERMAL ISOTROPIC This is thermal material property type 1 It allows isotropic thermal properties to be defined Card Format 1 of 2 1 2 3 4 5 6 7 8 Card Format 2 of 2 Type VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be chosen TRO Thermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT LT 0 function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation HC Heat capacity TC Thermal conductivity LS DYNA3D Version 936 19 231 MAT MAT MAT THERMAL ORTHOTROPIC This is thermal material property type 2 It allows orthotropic thermal properties to be defined Card Format 1 of 4 1 2 3 4 5 6 7 8 Card Format 2 of 4 Type Type 19 232 MAT LS DYNA3D Version 936 MAT Card Format 4 of 4 Type VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be chosen TRO Thermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number s
379. me step size after switch 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 Number of rigid parts to be switched to deformable EQ 0 no parts defined 10 4 DEFORMABLE TO RIGID LS DYNA3D Version 936 DEFORMABLE TO RIGID Remark Only surface to surface and node node to surface contacts can be used to activate automatic part switch 2 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 LS DYNA3D Version 936 10 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 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION PID Part ID of the part which is switched to a deformable material 10 6 DEFORMABLE TO RIGID LS DYNA3D Version 936 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 initi
380. ment or use of a dial box The left button down enables translation in the plane middle button rotation about axes in the plane and with right button down in the out of plane axis left and middle button down quit this mode Drag picked part to new position set with mouse Set or unset node numbering in subsequent views Set and unset drawing of a frame around the picture Animation display pause in seconds Time history plotting phase Similar to LS TAURUS Get element information with mouse Enable or disenable postscript mode on the PC and eps file is written as picture is drawn remove eofs and initgraphics for eps use G 3 Appendix G QUIT RANGE RAX RAY RESTORE RETURN RGB RX RY RZ SAVE SEQUENCE SHR SIP G 4 Same as execute Set fix range for contour levels range lt minvalue gt lt maxvalue gt Reflect model about xy plane restore command will switch off reflections Reflect model about yz plane restore command will switch off reflections Reflect model about zx plane restore command will switch off reflections Restores model to original position also switches off element and node numbers slice capper reflections and cut model Exit Change color red green blue element lt mat gt lt red gt lt green gt lt blue gt Rotate model about x axis Rotate model about y axis Rotate model about z axis Set or unset saving of display for animation Periodic
381. ments This restriction may be relaxed in a later version Pre decomposition There is an optional auxiliary serial program MPPPRE which creates a binary file containing decomposition information for the problem If MPPPRE is not used MPP LS DYNA3D will do the decomposition at run time The advantages of using MPPPRE are The parallel machine is not tied up while decomposition is done LS DYNA3D Version 936 1 49 INTRODUCTION INTRODUCTION e The start up time of the parallel run is greatly reduced If the problem is to be run more than once the decomposition need only be done once The problem can later be run on any number of processors which evenly divides the number of processors for which the decomposition was performed Output Files and Post Processing For performance reasons many of the ASCII output files normally created by LS DYNA3D have been combined into a new binary format used by MPP LS DYNA3D There is a post processing program DUMPBDB which reads this binary database of files and produces as output the corresponding ASCII files The new binary files will be created in the directory specified as the global directory in the pfile See Section 6 The file one per processor are named paour nnn where nnnn is replaced by the four digit processor number To convert these files to ASCII three steps are required as follows cd global directory cat DBOUT DBOUT DUMPBDB ABOUT Many of the
382. mping factor used for Belytschko Schwer beam type 1 only K Bulk Modulus define for fluid option only Tensor viscosity coefficient values between 1 and 5 should be okay CP Cavitation pressure default 1 0e 20 The axial and bending damping factors are used to damp down numerical noise The update of the force resultants F and moment resultants M includes the damping factors DA prop oar 2 At DB nt 2 2 t LS DYNA3D Version 936 19 5 MAT MAT For the fluid option the bulk modulus K has to be defined as Young s modulus and Poission s ratio are ignored With the fluid option fluid like behavior is obtained where the bulk modulus K and pressure rate p are given by E 3 1 2v p K and the shear modulus is set to zero A tensor viscosity is used which acts only the deviatoric stresses S x given in terms of the damping coefficient as Sit 2 VC AL a p j where AL is a characteristic element length a is the fluid bulk sound speed p is the fluid density and j is the deviatoric strain rate 19 6 MAT LS DYNA3D Version 936 MAT MAT OPTION TROPIC ELASTIC This is Material Type 2 This material is valid for modeling the elastic orthotropic behavior of solids shells and thick shells An anisotropic option is available for solid elements Options include ORTHO ANISO such that the keyword cards appear MAT ORTHOTROPIC ELASTIC
383. mputer System CFT Reference Manual Cray Research Incorporated Bloomington NM Publication No 2240009 1978 DeRuntz J A Jr Reference Material for USA The Underwater Shock Analysis Code USA STAGS and USA STAGS CFA Report LMSC P032568 Computational Mechanics Laboratory Lockheed Palo Alto Research Laboratory Palo Alto CA 1993 Dobratz B M LLNL Explosives Handbook Properties of Chemical Explosives and Explosive Simulants University of California Lawrence Livermore National Laboratory Rept UCRL 52997 1981 30 2 REF LS DYNA3D Version 936 REFERENCES Englemann B E R G Whirley and G L Goudreau A Simple Shell Element Formulation for Large Scale Elastoplastic Analysis CED Vol 3 Analytical and Computational Models of Shells A K Noor T Belytschko and J C Simo Editors 1989 pp 399 416 Flanagan D P and T Belytschko A Uniform Strain Hexahedron and Quadrilateral and Orthogonal Hourglass Control Int J Numer Meths Eng 17 679 706 1981 Ginsberg M and J Johnson Benchmarking the Performance of Physical Impact Simulation Software on Vector and Parallel Computers Applications Track of Supercomputing IEEE monograph Computer Society Press March 1989 Giroux E D HEMP User s Manual University of California Lawrence Livermore National Laboratory Rept UCRL 51079 1973 Goudreau G L and J O Hallquist Recent Developments in Large Scale Finite Element Lagrang
384. n b Figure 5 1 Nodal normal and segment based projection is used in the contact options LS DYNA3D Version 936 5 5 CONTACT CONTACT Read the following card here if and only if the option TITLE is specified Optional 1 2 Card Format Cards 1 to 3 are mandatory for all contact types Card 1 1 2 3 4 5 6 55 MSTYP SBOXID MBOXID Card 2 1 2 3 4 5 6 5 6 CONTACT LS DYNA3D Version 936 CONTACT The variables FSF and VSF below be overridden segment by segment on the SET SEGMENT or SET SHELL OPTION cards for the slave surface only as and 4 and for the master surface only as Al and A2 See SET SEGMENT and SET SHELL OPTION Card 3 1 2 3 4 5 6 7 8 SST MST SFST SFMT FSF element element Additional Card required for CONSTRAINT contact Card 4 1 2 3 4 5 6 7 8 Variable Default Additional Card required for DRAWBEAD contact Card 4 1 2 3 4 5 6 7 8 Variable LCIDRF LCIDNF DBDTH DFSCL NUMINT LS DYNA3D Version 936 5 7 CONTACT CONTACT Additional Card required for ERODING contact Card 4 1 2 3 4 5 6 7 8 Default Additional Card required for TIEBREAK NODE contact These attributes can be overridden node by node on the SET NODE OPTION cards Card 4 1 2 3 4 5 6 7 8 Additional Card required for TIEBREAK SURFACE contact These attributes can be overridden segment by segment on the SET SEGMENT or SET SHELL OPTION cards for the slave surfa
385. n in LS TAURUS database see remark 2 below Optional nodal point for visualization Optional nodal point for visualization Optional nodal point for visualization LS DYNA3D Version 936 RIGIDWALL 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 The 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 Ha dva relative Hb Msb Ltp e dvbVrelative b Orthotropic rigid walls can 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 nxXd and that a bxn where n is the normal vector to the rigid wall If d is in the plane of the rigid wall the a is identical to d See Figure 22 3 below LS DYNA3D Version 936 22 13 RIGIDWALL RIGIDWALL m N gt p didi p 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
386. n two master nodes is sometimes necessary during ALE smoothing 2 2 ALE LS DYNA3D Version 936 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_CONVECTION_OPTION BOUNDARY_CYCLIC BOUNDARY_FLUX_OPTION BOUNDARY_NON_REFLECTING BOUNDARY_PRESCRIBED_MOTION_OPTION BOUNDARY_PRESSURE_OUTFLOW_OPTION BOUNDARY_RADIATION_OPTION BOUNDARY_SLIDING_PLANE BOUNDARY_SPC_OPTION BOUNDARY_SYMMETRY_FAILURE BOUNDARY_TEMPERATURE_OPTION BOUNDARY_USA_SURFACE LS DYNA3D Version 936 3 1 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 5 6 7 8 Variable Default For the SEGMENT option define the following card Card Format Card 1 of 2 Card 1 1 2 3 4 5 6 7 8 Variable Default 3 2 BOUNDARY LS DYNA3D Version 936 BOUNDARY Define the following card for both options Card Format Card 2 of 2 Card 1 1 2 3 4 5 6 7 8 Default VARIABLE DESCRIPTION SSID Segment set ID see SET_SEGMENT N1 N2 Node ID s defining segment HLCID Load curve ID for heat transfer coefficient GT 0 function
387. nally several parameters affecting the VDA surface iteration routines can be reset in the file vda These parameters and their default values in square brackets are gap 5 0 track 2 0 track2 5 0 ntrack 4 The maximum allowable surface gap to be filled in during the iterations Points following the surface will effectively extend the edges of surfaces if necessary to keep them from falling through cracks in the surface smaller than this This number should be set as small as possible while still allowing correct results In particular if your VDA surfaces are well formed having no gaps this parameter can be set to 0 0 The default value is 5 0 A point must be within this distance of contact to be continually tracked When a point not being tracked comes close to a surface a global search is performed to find the near surface point While a point is being tracked iterations are performed every cycle These iterations are much faster but if the point is far away it is faster to occasionally do the global search The default value is 2 0 Every VDA surface is surrounded by a bounding box When a global search needs to be performed but the distance from a point to this box is gt track2 the actual global search is not performed This will require another global search to be performed sooner than if the actual distance to the surface were known but also allows many global searches to be skipped The default value is 5
388. nalysis Comp Struct 19 1 8 1984 Bammann D J and E C Aifantis A Model for Finite Deformation Plasticity Acta Mechanica 70 1 13 1987 Bammann D J and G Johnson On the Kinematics of Finite Deformation Plasticity Acta Mechanica 69 97 117 1987 Bammann D J Modeling the Temperature and Strain Rate Dependent Large Deformation of Metals Proceedings of the 11th US National Congress of Applied Mechanics Tuscon AZ 1989 Bammann D J M L Chiesa A McDonald W A Kawahara J J Dike and V D Revelli Predictions of Ductile Failure in Metal Structures in AMD Vol 107 Failure Criteria and Analysis in Dynamic Response Edited by H E Lindberg 7 12 1990 Bandak F A private communications U S Dept of Trans Division of Biomechanics Research 400 7th St S W Washington D C 20590 1991 Barlat F and J Lian Plastic Behavior and Stretchability of Sheet Metals Part I A Yield Function for Orthotropic Sheets Under Plane Stress Conditions Int J of Plasticity Vol 5 pp 51 66 1989 Barlat F D J Lege and J C Brem A Six Component Yield Function for Anisotropic Materials Int J of Plasticity 7 693 712 1991 Bazeley G P W K Cheung R M Irons and O C Zienkiewicz Triangular Elements in Plate Bending Confirming and Nonconforming Solutions in Matrix Methods and Structural Mechanics Proc Conf on Matrix Methods in Structural Analysis Rept AFFDL R 66 80
389. nates and is fixed permanently in space The third option 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 Variable VARIABLE DESCRIPTION VID Orientation vector ID A unique 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 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 XT x value of orientation vector Define if IOP 0 1 YT y value of orientation vector Define if IOP 0 1 ZT z value of orientation vector Define if IOP 0 1 NIDI Node 1 ID Define if IOP 2 NID2 Node 2 ID Define if IOP 2 LS DYNA3D Version 936 9 9 DEFINE 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 desired to
390. ne 19 52 WEG 19 55 THERMAL noter rte Prieto bier Pre divanes 19 59 MAT COMPOSITE DAMAGE mem BRI 19 62 MAT TEMPERATURE DEPENDENT 19 65 MAT PIECEWISE LINEAR PLASTICITY 9 19 68 MAT GEOLOGIC CAP MODEL e 19 72 MAHONEY COMB 19 79 MAT MOONEY RIVLIN 19 86 vi LS DYNA3D Version 936 TABLE OF CONTENTS eere erheben 19 89 MAT FORCE EIMITED RERO TRIES RR ie UR 19 90 MAT CLOSED FORM SHELL PLASTICITY eere eene 19 96 MAT FRAZER NASH RUBBER 19 97 LAMINATED GEASS otii reb tenete E D t RR EHE 19 100 MAT BARLAT ANISOTROPIC PLASTICITY eee 19 102 ere UR RAE Hist pe irte Erbe 19 105 MAT PLASTIC GREEN NAGHBHDI 0 19 109 MAT 3 PARAMETER BARLAT ete iere eR RE ERR 19 110 MAT TRANSVERSELY ANISOTROPIC ELASTIC 19 114 MAT BLEATZ KO FOAM 5 pte bre Lee tp eo t ERE RENE RS 19 117 MAT TR
391. ned through a midsurface only 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 Card Format 1018 1 2 3 4 5 6 7 8 9 VARIABLE DESCRIPTION EID Element ID Unique numbers have to be used PID Part ID see PART N1 Nodal point 1 N2 Nodal point 2 N3 Nodal point 3 N8 Nodal point 8 LS DYNA3D Version 936 11 33 ELEMENT ELEMENT Remark l The correct numbering of the nodes is essential for correct use Nodes to n4 define the lower surface and nodes ns to ng define the upper surface The integration points lie along the t axis as depicted in Figure 11 10 Extreme care must be used in defining the connectivity to insure proper orientation Figure 11 10 Solid 8 node Shell Element 11 34 ELEMENT LS DYNA3D Version 936 EOS EOS LS DYNAS3D 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 EOS_LINEAR_POLYNOMIAL TYPE 2 EOS_JWL TYPE 3 EOS_SACK_ TUESDAY TYPE 4 EOS_GRUNEISEN TYPE 5 EOS RATIO OF POLYNOMIALS TYPE 6 EOS LINEAR POLYNOMIAL WITH ENERGY LEAK TYPE 7 EOS IGNITION AND GROWTH OF REACTION IN HE TYPE 8 5 TABULATED COMPACTION TYPE 9 EOS TA
392. nent of shear stress may have its own load curve See notes below LCAB Load curve ID see DEFINE CURVE for sigma ab versus either relative volume or volumetric strain Default LCAB LCS See notes below LS DYNA3D Version 936 19 79 MAT MAT VARIABLE LCBC LCCA LCRS EAAU EBBU ECCU GABU GBCU GCAU AOPT XP YP ZP Al A2 A3 D1 D2 D3 DESCRIPTION Load curve ID see DEFINE CURVE for sigma bc versus either relative volume or volumetric strain Default LCBC LCS See notes below Load curve ID see DEFINE CURVE or sigma ca versus either relative volume or volumetric strain Default LCCA LCS See notes below Load curve ID see DEFINE CURVE for strain rate effects defining the scale factor versus strain rate J This is optional The curves defined above are scaled using this curve Elastic modulus in uncompressed configuration Elastic modulus Eppy in uncompressed configuration Elastic modulus Eccu in uncompressed configuration Shear modulus Gabu in uncompressed configuration Shear modulus Gpcy in uncompressed configuration Shear modulus Geau in uncompressed configuration Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes
393. nes 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 4 Related switch set The related switch set is another automatic switch set that must be activated before this part switch can take place EQ 0 no related switch set 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 Flag to delete or activate rigid walls EQ 0 no change EQ 1 delete EQ 2 activate Maximum permitted ti
394. ng s modulus in c direction Vba Poisson s ratio ba Poisson ratio ca Veb Poisson s ratio cb Gap Shear modulus ab Gbc Shear modulus bc Gea Shear modulus coefficients of thermal expansion in the a direction coefficients of thermal expansion in the b direction coefficients of thermal expansion in the c direction Material axes option see Figure 19 1 EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector EQ 4 0 locally orthotropic in cylindrical coordinate system with the material axes determined by a vector v and an orginating point P They define the axis of symmetry Coordinates of point p for AOPT 1 Components of vector a for AOPT
395. normal LS DYNA3D files will have corresponding collections of files produced by MPP LS DYNA3D with one per processor These include D3DUMP files new names D3DUMP nnnn the MESSAG files now MESnnnn and others Most of these will be found in the local directory specified in the pfile The format of the D3PLOT file has not been changed It will be created in the global directory and can be directly handled with our graphics post processor LS TAURUS Parallel Specific Options There is a new command line option p pfile pfile contains MPP specific parameters that affect the execution of the program The file is split into sections with several options in each section Currently three sections directory decomposition and contact are available First here is a sample pfile 1 50 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION directory global rundir local tmp rundir contact inititer 4 This file is case insensitive and free format input with the exception that each word or bracket must be surrounded on both sides with either a space tab or new line character The section and options currently supported are Directory Holds directory specific options global path Relative path to a directory accessible to all processors This directory will be created if necessary Default current working directory local path Relative path to a processor specific local directory for scratch files This directory
396. nsile cutoff maximum principal stress for failure Cohesion Pressure hardening coefficient Pressure hardening coefficient Cohesion for failed material Pressure hardening coefficient for failed material Damage scaling factor Percent reinforcement Elastic modulus for reinforcement Poisson s ratio for reinforcement Initial yield stress Tangent modulus plastic hardening modulus Load curve ID giving rate sensitivity for principal material see DEFINE_CURVE Load curve ID giving rate sensitivity for reinforcement see DEFINE CURVE Effective plastic strain if AO or Al are nonzero Otherwise define pressure Effective stress For the constant Poisson s ratio model the shear modulus is computed from the bulk modulus For the constant shear modulus model Poisson s ratio is computed from the bulk modulus The bulk modulus is determined by the equation of state If zero values are specified for ag and aj EPSi are taken to be pressure values instead of values of effective plastic strain 19 46 MAT LS DYNA3D Version 936 MAT If a negative value is specified for ag the value given for sigf is assumed to be the unconfined compressive strength of the principal material instead of the tensile cutoff value In this case values for the tensile cutoff and pressure hardening coefficients are calculated internally as follows sigf 1 7 f c 2 ucf 1 3 ag 1 4 f c aj 1 3 a 1 3 f
397. nt nyy 4 node shell normal resultant nxy 4 node shell thickness 4 node shell 8 11 DATABASE DATABASE Table 8 3 Shell and Thick Shell Element Quantities cont Component Number Quantity 8 12 DATABASE 3 32 33 34 35 36 37 38 39 40 4l 42 43 44 45 46 47 48 49 50 5 52 53 54 55 56 57 58 59 60 element dependent variable element dependent variable inner surface x strain inner surface y strain inner surface z strain inner surface xy strain inner surface yz strain inner surface zx strain outer surface x strain outer surface y strain outer surface z strain outer surface xy strain outer surface yz strain outer surface zx strain internal energy midsuface effective stress inner surface effective stress outer surface effective stress midsurface max principal strain through thickness strain midsurface min principal strain lower surface effective strain lower surface max principal strain through thickness strain lower surface min principal strain lower surface effective strain upper surface max principal strain through thickness strain upper surface min principal strain upper surface effective strain LS DYNA3D Version 936 DATABASE Table 8 4 Beam Element Quantities Component Number Quantity 1 x force resultant y force resultant z force resultant y moment resultant 2 3 4 x moment resultant 5 6 z moment resultant
398. nt 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 DYNA3D Version 936 11 29 ELEMENT ELEMENT Remarks 1 Four six and eight node elements are shown in Figure 11 8 Input of nodes on the element cards for the two degenerate elements is 4 node N1 N2 N3 N4 N4 N4 N4 4 6 node N2 N3 N4 N5 N5 6 N6 or N2 N3 N3 N4 5 N6 N6 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 11 9 cxa lt These vectors are internally normalized within LS DYNA3D 11 30 ELEMENT LS DYNA3D Version 936 ELEMENT 4 N solids 7 5 6 AA 1 4 1 M Ng N4 N4 N4 n n 2 5 Ww 4 node n 6 node ni n n ns ns no ne Figure 11 8 Four six and eight node solid elements Nodes 1 4 are on the bottom surface LS DYNA3D Version 936 11 31 ELEMENT ELEMENT Figure 11 9 Two vectors a and d are defined and the triad is computed and stored Vectors b and d lie in the same plane 11 32 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT TSHELL Purpose Define an eight node thick shell element This shell element can be used as an alternative to the 4 noded shell elements defi
399. ntact EQ 1 0 no sliding after contact 0 lt FRIC lt 1 Coulomb friction coefficient SFRICA Static friction coefficient in local a direction Usa see Figure 22 2 LS DYNA3D Version 936 22 11 RIGIDWALL RIGIDWALL VARIABLE SFRCIB DFRICA DFRICB DECAYA DECAYB NODEI NODE2 D1 D2 D3 XHEV YHEV ZHEV LENL LENM MASS VO SOFT SSID 22 12 RIGIDWALL DESCRIPTION Static friction coefficient in local b direction Usb Dynamic friction coefficient in local a direction Uka Dynamic friction coefficient in local b direction Ukb 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 dj x component of vector alternative to definition with nodes above see Figure 22 2 This vector is fixed as a funtion of time d2 y component of vector d3 z component of vector x coordinate of head of edge vector 1 see Figure 22 3 y coordinate of head of edge vector 1 z coordinate of head of edge vector Length of l edge Length of m edge Total mass of stonewall Initial velocity of stonewall in direction of defining vector n Number of cycles to zero relative velocity to reduce force spike Segment set identification number for defining areas for force output see SET SEGMENT and remark 1 below Optional nodal point for visualizatio
400. nterfaces 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 Type VARIABLE DESCRIPTION SID Set ID see SET NODE or SET SEGMENT LS DYNA3D Version 936 17 1 INTERFACE INTERFACE INTERFACE LINKING 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 17 2 INTERFACE LS DYNA3D Version 936 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 VARIABLE DESCRIPTION SSID Segment set to be moved by interface file IFID Interface ID in interface file LS DYNA3D Version 936 17 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 VARIABLE DESCRIPTION NSID Node
401. ntifier 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 formation specified a shear factor SHRF a numerical integration rule NIP and so 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 DYNA3D use uniformly reduced numerical integration zero energy deformation modes may develop These modes are controlled numerically LS DYNA3D Version 936 1 9 INTRODUCTION INTRODUCTION 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 DYNA3D 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 DYNA3D An a
402. nts below BX x direction for local axis B By see comments below BY y direction for local axis B see comments below BZ z direction for local axis B Bz see comments below INOUT In out flag Allows contact from the inside or the outside default of the entity EQ 0 slave nodes exist outside of the entity EQ 1 slave nodes exist inside the entity Gl Entity coefficient g CAL3D MADYMO plane or ellipse number for coupled analysis see Appendix F G2 Entity coefficient g2 see comments below G3 Entity coefficient g3 see comments below G4 Entity coefficient g4 see comments below G5 Entity coefficient g5 see comments below G6 Entity coefficient g6 see comments below G7 Entity coefficient g7 see comments below 5 22 CONTACT LS DYNA3D Version 936 CONTACT 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 The coordinates 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 a
403. number If less than 4 cards are input reading is stopped by a control card Card 3 etc VARIABLE DESCRIPTION MID Material identification A unique number has to be defined RO Mass density EG Young s modulus for glass PRG Poisson s ratio for glass LS DYNA3D Version 936 19 99 MAT MAT VARIABLE DESCRIPTION SYG Yield stress for glass ETG Plastic hardening modulus for glass EFG Plastic strain at failure for glass EP Young s modulus for polymer PRP Poisson s ratio for polymer SYP Yield stress for polymer ETP Plastic hardening modulus for polymer F1 FN Integration point material fn 0 0 glass fn 1 0 polymer A user defined integration rule must be specified see INTEGRATION SHELL Isotropic hardening for both materials is assumed The material to which the glass is bonded is assumed to stretch plastically without failure A user defined integration rule specifies the thickness of the layers making up the glass F defines whether the integration point is glass 0 0 or polymer 1 0 The material definition F has to be given for the same number of integration points NIPTS as specified in the rule A maximum of 32 layers is allowed 19 100 MAT LS DYNA3D Version 936 MAT MAT BARLAT ANISOTROPIC PLASTICITY This is Material Type 33 This model was developed by Barlat Lege and Brem 1991 for modelling anisotropic material behavior in forming processes The finite element implementation of th
404. number m Rigid body updates are performed by MADYMO CAL3D ALIAS VDA surface alias name see Appendix I LS DYNA3D Version 936 19 55 MAT MAT VARIABLE DESCRIPTION CMO Center of mass constraint option CMO EQ 1 0 constraints applied in global directions EQ 1 0 constraints applied in local directions SPC constraint CONI First constraint parameter If CMO 1 0 then specify global 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 If CM0 1 0 then specify local coordinate system ID See DEFINE_ COORDINATE OPTION CON2 Second constraint parameter If CMO 1 0 then specify global rotational constraint 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 rotations EQ 5 constrained y and z rotations EQ 6 constrained z and x rotations EQ 7 constrained x y and z rotations If CM0 1 0 then specify local SPC constraint EQ 000000 no constraint EQ 100000 constrained x translation EQ 010000 constrained y translation EQ 001000 constrained z translation EQ 000100 constrained x rotation EQ 000010 constrained y rotation EQ 000001 constrain
405. oblem 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 D32DUMPnn then the following procedure is followed Create the restart input deck if required as described in the Restart Section of this manual Call this file restartinput 2 Byinvoking the execution line LS DYNA3D I restartinput R D3DUMPnn execution begins If no alterations to the model are made then the execution line LS DYNA3D 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 RZD3DUMPnn 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 e Sheet metalforming continued with different tools for modeling a multi stage forming process LS DYNA3D Version 936 1 37 INTRODUCTION INTRODUCTION As
406. 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 An 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 LS DYNA3D Version 936 L3 INTRODUCTION INTRODUCTION 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 VAX 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 metalforming simulations and composite analysis became a reality This version included shell thickness c
407. of viscosity with temperature can be defined in any one of the 3 ways 19 152 MAT LS DYNA3D Version 936 MAT 1 Constant V Vo Do not define constants A B and C or the piecewise curve leave card 4 blank i V Vo 10 A T B C Piecewise curve define the variation of viscosity with temperature Note Viscosity is inactive during dynamic relaxation LS DYNA3D Version 936 19 153 MAT MAT MAT_KELVIN MAXWELL_VISCOELASTIC This is Material Type 61 It is a classical Kelvin Maxwell model for modelling viscoelastic bodies e g foams Only valid for solid elements See also notes below Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density BULK Bulk modulus elastic GO Short time shear modulus Go GI Long time infinite shear modulus DC Maxwell decay constant FO 0 0 or Kelvin relaxation constant t FO 1 0 FO Formulation option EQ 0 0 Maxwell EQ 1 0 Kelvin SO Strain logarithmic output option to be plotted as component 7 in LS TAURUS D3PLOT file which is the effective plastic strain component The maximum values are updated for each element each time step EQ 0 0 maximum principal strain that occurs during the calculation EQ 1 0 maximum magnitude of the principal strain values that occurs during the calculation EQ 2 0 maximum effective strain that occurs during the calculation 19
408. ollowing criteria 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 Type2 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 Type4 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 11 20 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SEATBELT SLIPRING Purpose Define seat belt slip ring Card Format Default Remarks VARIABLE DESCRIPTION SBSRID Slipring ID SBIDI Seat belt element 1 ID SBID2 Seat belt element 2 ID FC Coulomb friction coefficient SBRNID Slip ring node NID Remarks 1 Slip ring ID s should start at 1 and be consecutive 2 Elements 1 and 2 should share node which is coincident with the slip ring node The slip r
409. olume polyurethane foam rubber with a Poisson s ratio of 0 25 In terms of the strain invariants I II and III the second Piola Kirchhoff stresses are given as 1 II _1 SY G 16 C VI z i where Cj is the right Cauchy Green strain tensor This stress measure is transformed to the Cauchy stress according to the relationship ij 2 o FF Six where Fj is the deformation gradient tensor 19 116 MAT LS DYNA3D Version 936 MAT The second Piola Kirchhoff stress is computed as 1 Y where V is the relative volume is the right Cauchy Green strain tensor and v is Poisson s ratio which is set to 25 internally This stress measure is transformed to the Cauchy stress Ojj according to the relationship V 1 Fik Sik where Fj is the deformation gradient tensor LS DYNA3D Version 936 19 117 MAT MAT MAT FLD TRANSVERSELY ANISOTROPIC This is Material Type 39 This model is for simulating sheet forming processes with anisotropic material Only transverse anisotropy can be considered Optionally an arbitrary dependency of stress and effective plastic strain can be defined via a load curve A flow limit diagram can be defined using a curve and is used to compute the maximum strain ratio which can be plotted in LS TAURUS This plasticity model is fully iterative and is available only for shell elements Also see the notes below Card Format Card 1 1 2 3 4 5 6
410. olume weighting CFAC Smoothing weight factor Isoparametric DFAC Smoothing weight factor Equipotential START Start time for smoothing END End time for smoothing AAFAC ALE advection factor See also SECTION SOLID OPTION LS DYNA3D Version 936 6 5 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 Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION Q2 Default quadratic viscosity coefficient Q1 Default linear viscosity coefficient See also Chapter 18 in Theoretical Manual 6 6 CONTROL LS DYNA3D Version 936 CONTROL CONTROL CONTACT Purpose Change defaults for computation with contact surfaces Card Format Card 1 1 2 3 4 5 6 7 8 Variable SLSFAC RWPNAL ISLCHK SHLTHK PENOPT THKCHG ORIEN Default Card 2 1 2 3 4 5 6 7 8 Variable USRSTR USRFRC NSBCS INTERM XPENE SSTHK ECDT TIEDPRJ VARIABLE DESCRIPTION SLSFAC Scale factor for sliding 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 wall
411. on requires that each reference node is unique to the beam EQ 0 no update EQ 1 update This is generally recommended IACCOP Averaged accelerations from velocities in file Onodout and the time history database file Od3thdtO EQ 0 no average default EQ 1 averaged between output intervals OPIFS Output interval for interface file Et see INTRODUCTION Execution syntax IPNINT Print initial time step sizes for all elements on the first cycle EQ 0 no printout EQ 1 the governing time step sizes for each element are printed IKEDIT Problem status report interval steps to the D3HSP printed output file 6 18 CONTROL LS DYNA3D Version 936 CONTROL CONTROL PARALLEL Purpose Control parallel processing usage for shared memory computers Card Format Default VARIABLE DESCRIPTION NCPU Number of cpus used NUMRHS Number of right hand sides written EQ 0 same as NCPU EQ 1 write one only ACCU Accuracy flag for parallel solution NCPU gt 1 EQ 1 on default EQ 2 off for a faster solution It is recommended to always set NUMRHS NCPU since great improvements in the parallel performance are obtained Setting NUMRHS to one reduces storage by one right hand side vector for each processor The accuracy flag ACCU provides for identical results or nearly so whether one two or more processors are used LS DYNA3D Version 936 6 19 CONTROL CONTROL CONTROL SHELL Purpose Provide controls for compu
412. on 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 DYNA3D Version 936 8 7 DATABASE DATABASE Format 1 of 1 for the SET option Variable NSID HSID BSID SSID TSID DSID EE MN Default VARIABLE DESCRIPTION PSID Part set ID If zero all parts are included XCT x coordinate of tail of any outward drawn normal vector N originating on wall tail and terminating in space head see Figure 8 1 YCT y coordinate of tail of normal vector N ZCT z coordinate of tail of normal vector N XCH x coordinate of head of normal vector N YCH y coordinate of head of normal vector N ZCH z coordinate of head of normal vector N XHEV x coordinate of head of edge vector L YHEV y coordinate of head of edge vector L ZHEV z coordinate of head of edge vector L LENL Length of edge a in L direction LENM Length of edge b in M direction NSID Nodal set ID see SET NODE OPTION HSID Solid element set ID see SOLID BSID Beam element set ID see SET BEAM SSID Shell element set ID see SET SHELL OPTION TSID Thick shell element set ID see SET TSHELL DSID Discrete element set ID see SET DISCRETE 8 8 DATABASE LS DYNA3D Version 936 DATABASE DATABASE EXTENT OPTION Options include AVS MPGS MOVI
413. onstrained 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 LS DYNA3D Version 936 20 1 NODE NODE VARIABLE DESCRIPTION RC Rotational constraint 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 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 using options in the CONSTRAINT section of the manual 2 A node without an element or a mass attached to it will be assigned a very small amount of mass 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 20 2 NODE LS DYNA3D Version 936 PART PART PART OPTION Available options are BLANK PART INERTIA PART REPOSITION Purpose Define parts 1 combine material and section information as well as hourglass control thermal properties and general specification for adaptivity Th
414. optionally with linear viscoelasticity as outlined by Christensen 1980 Card Format Card 1 1 2 3 4 5 6 7 8 Type Card 2 if N gt 0 a least squares fit is computed from unixial data Card Format Card 2 1 2 3 4 5 6 7 8 Type Card 2 if N 0 define the following constants Card Format Card 2 1 2 3 4 5 6 7 8 Variable 19 190 MAT LS DYNA3D Version 936 MAT Card Format for Viscoelastic Constants Up to 6 cards may be input A keyword card with a in column 1 terminates this input if less than 6 cards are used Optional Cards VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density PR Poissons ratio 7 49 is recommended smaller values may not work and should not be used N order of fit currently 3 if N50 test information from a uniaxial test are voided SGL Specimen gauge length SW Specimen width ST Specimen thickness LCID Load curve ID giving the force versus actual change in the gauge length If N 0 the following constants have to be defined C10 C10 C01 C11 C20 C20 C02 Co2 GI Optional shear relaxation modulus for the ith term BETAI Optional decay constant if ith term LS DYNA3D Version 936 19 191 MAT MAT Rubber is generally considered to be fully incompressible since the bulk modulus greatly exceeds the shear modulus in magnitude To model the rubber as an unconstrained material a hydrostatic work term Wy J
415. or The square root of the second invariant of the deviatoric stress tensor 7p is found from the deviatoric stresses s 1 gt SijSij and is the objective scalar measure of the distortional or shearing stress The first invariant of the stress is the trace of the stress tensor The cap model consists of three surfaces in J2p space as shown in Figure 19 6 as First there is a failure envelope surface denoted f in the figure The functional form of is min F J Ld where F is given by LS DYNA3D Version 936 19 73 MAT MAT F J 8 Y exp BJi 8J and Thnises This failure envelop surface is fixed in JJ5p space and therefore does not harden unless kinematic hardening is present Next there is a cap surface denoted f in the figure with f2 given by fa Jap F J1 X where is defined by f y x 697 Hf Ls 169 X k is the intersection of the cap surface with the Jj axis X Kk 2 K RF and L t is defined by L x gt 0 lt 0 The hardening parameter is related to the plastic volume change through the hardening law eb wh exp D X x Geometrically is seen in the figure as the Jj coordinate of the intersection of the cap surface and the failure surface Finally there is the tension cutoff surface denoted f3 in the figure The function f3 is given by y T9
416. osen TRO Thermal density EQ 0 0 default to structural density TGRLC Thermal generation rate curve number see DEFINE CURVE GT 0 function versus time EQ 0 use constant multiplier value TGMULT LT 0 function versus temperature TGMULT Thermal generation rate multiplier EQ 0 0 no heat generation T8 Temperatures T1 T8 1 8 Heat capacity at 1 T8 K8 Thermal conductivity at T1 T8 LS DYNA3D Version 936 19 235 MAT MAT MAT THERMAL ORTHOTROPIC TD This is thermal material property type 4 It allows temperture dependent orthotropic properties to be defined The temperature dependency is defined by specifying a minimum of two and a maximum of eight data points The properties must be defined for the tempertaure range that the material will see in the analysis Card Format 1 of 8 1 2 3 4 5 6 7 8 Card Format 2 of 8 Type Type 19 236 MAT LS DYNA3D Version 936 MAT Card Format 4 of 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 Card Format 5 of 8 1 2 3 4 5 6 7 8 Variable K2 K2 K2 K2 K2 K2 K2 K2 1 2 3 4 5 6 7 8 Card Format 6 of 8 1 2 3 4 5 6 7 8 Variable K3 K3 K3 K3 K3 K3 K3 K3 1 2 3 4 5 6 7 8 Card Format 7 of 8 Type LS DYNA3D Version 936 19 237 MAT MAT Card Format 8 of 8 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION TMID Thermal material identification a unique number has to be chosen TRO Th
417. ould 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 3 3 N3 x43 3 3 aces DM 22712 respectively Card 2 7 8 LS DYNA3D Version 936 15 7 INITIAL INITIAL VARIABLE EID NPLANE NTHICK T SIGIJ EPS 15 8 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 Effective plastic strain LS DYNA3D Version 936 INITIAL 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 DYNA3D solid elements the average value will be taken Card Format Card 1 2 3 4 5 6 7 8 m els 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 2 2493 EJ 3 3 223 3 3 5 3 3 3 9 3 3 3 43 v3 X3 43 V3 _v3
418. ow this pressure stiffness and strength disappears this is also the zero pressure for pressure varying properties b 67 Go p po B Exponent for pressure sensitive moduli b zs b must lie Ko Po in the range 0 lt 6 lt 1 Values close to 1 are not recommended because the pressure becomes indeterminate A0 Yield function constant Default 1 0 see Material Type 5 Al Yield function constant Default 0 0 see Material Type 5 A2 Yield function constant a2 Default 0 0 see Material Type 5 DF Damping factor Must be in the range O lt dfs lt 1 EQ 0 no damping EQ 1 maximum damping RP Reference pressure for following input data GAMI shear strain GAM2 shear strain GAM3 shear strain GAMA shear strain 5 shear strain 19 202 MAT LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION TAUI shear stress at TAU2 T2 shear stress at Y2 TAU3 shear stress at TAUA T4 shear stress at TAUS 75 shear stress at Y5 The constants ao aj a2 govern the pressure sensitivity of the yield stress Only the ratios between these values are important the absolute stress values are take from the stress strain curve The stress strain pairs T1 Y5 75 define a shear stress versus shear strain curve The first point on the curve is assumed by default to be 0 0 and does not need to be entered The slope of the curve must decrease with
419. p size TSSFAC Scale factor for computed time step old name SCFT Default 90 if high explosives are used the default is lowered to 67 ISDO 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 EQ 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 ELE MENTS ARE USED TSLIMT 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 PONER 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 6 30 CONTROL LS DYNA3D Version 936 VARIABLE DT2MS LCTM ERODE MSIST LS DYNA3D Version 936 CONTROL DESCRIPTION Time step size for mass scaled solutions DT2MS Positive value
420. pherical 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 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 1 16 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION 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 a
421. placements are coupled A brittle failure can be specified Card Format 1 2 3 rows Poe 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 Remarks 1 Nodes connected by a spotweld 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 DYNA3D Version 936 4 39 CONSTRAINED CONSTRAINED 2 Failure of the spotwelds occurs when n m Sn 5 where fn and f are the normal and shear interface force Component fn is nonzero for tensile values only 4 40 CONSTRAINED LS DYNA3D Version 936 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 Default Remarks VARIABLE DESCRIPTION SNSID Slave node set ID see SET NODE OPTION MNSID Master node set ID s
422. plot during execution SEQ lt of cycles gt lt commands gt EXE Shrink element facets towards centoids in subsequent views shrink lt value gt Select shell integration point for contour SIP lt gt LS DYNA3D Version 936 SLICE SNORMAL SPOT TAURUS TRIAD TSHELL TV TX TY TZ V VECTOR v ord ZB ZIN ZMA LS DYNA3D Version 936 Appendix G Slice model a z minimum plane slice value in normalized model dimension this feature is removed after using restore Slice enables internal details for brick elements to be used to generate new polygons on the slice plane Set or unset display of shell direction normals to indicate topology order Draw node numbers on model spot first gt last for range LS TAURUS database TAU state gt or state state gt reads LS TAURUS file to extract previous state data Set or unset display of axis triad Set or unset shell element thickness simulation in subsequent views Change display type Translates model along x axis Translates model along y axis Translates model along z axis Display model using painters algorithm View with vector arrows of velocity or displacement lt v gt or lt d gt Switch on or off zbuffer algorithm for subsequent view or draw commands Zoom in using mouse to set display size and position Set position of zmax plane ZMAX lt value in normalized model dimesions gt G 5
423. 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 Variable Default Card 2 3 4 etc Put one point per card E20 0 Input is terminated when a O DEFINE CURVE card is found Variable Default 9 10 DEFINE LS DYNA3D Version 936 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 LS DYNA3D Version 936 9 11 DEFINE DEFINE DEFINE
424. r 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 Maximum penetration distance for old type 3 5 and 10 contact see page 5 3 Also see Table 5 1 EQ 0 Use small penetration search and value calculated from thickness and XPENE see CONTROL CONTACT GT 0 Ignore element thickness and XPENE use this value instead Note PENCHK must be set to zero see above on Card 2 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 LS DYNA3D Version 936 5 15 CONTACT CONTACT VARIABLE DESCRIPTION SHLTHK Define if and only if THKOPT above equals 1 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 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
425. r the model is to set the LS DYNA3D rigid body coupling option to 2 0 This caused LS DYNA3D to search all of the ellipsoids connected to the appropriate segment and generate meshes which are then slaved the OSP dummy Thus with minimal input a complete dummy may be generated and the kinematics may be traced in LS DYNA3D and displayed in the LS DYNA3D post processor LS TAURUS Once the basic dummy coupling has been accomplished the deformable finite element structure can be added Assuming that an ellipsoid is available for the steering wheel a flat airbag can be added in the proper location One or more nodes must be attached to the steering wheel This is done by identifying the attached nodes as Extra Nodes for Rigid Body which is input in LS DYNA3D by CONSTRAINED EXTRA NODES Option The nodes are slaved to the LS DYNA3D material which has been coupled to the MADYMO steering wheel model Contact must now be identified between the airbag and the steering wheel the windshield and the various body parts which may be affected This requires the use of one geometric contact entity see CONTACT ENTITY for each plane or ellipsoid which may interact with the airbag A control volume specifying inflation properties for the airbag must be specified see AIRBAG OPTION to complete the model AIRBAG MODELING Modeling of airbags is accomplished by use of shell or membrane elements in conjunction with a control volume see AIRBAG OPTION and possibly
426. rakakis Papadrakakis 1981 EQ 0 not active EQ 1 active EDTTL Convergence tolerance on automatic control of dynamic relaxation IDRFLG Dynamic relaxation flag for stress initialization EQ 1 dynamic relaxation is activated and time history output is produced during dynamic relaxation see note 2 below EQ 0 not active EQ 1 dynamic relaxation is activated EQ 2 initialization to a prescribed geometry 6 14 CONTROL LS DYNA3D Version 936 CONTROL Remark 1 Stress initialization in LS DYNA3D for small strains may be accomplished by linking to an implicit code option 2 A displacement state is required that gives for each nodal point its label xyz displacements and xyz rotations and temperature This data is read from unit 7 m with the format 18 6e15 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 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 LS DYNA3D Version 936 6 15 CONTROL CONTROL CONTROL ENERGY Purpose Provide controls for energy dissipation options Card Format Default VARIABLE DESCRIPTION HGEN Hourglass energy calculation option This option requires significant additional storage and increase
427. rd 1 1 2 3 Card 2 1 none 15 12 INITIAL LS DYNA3D Version 936 VARIABLE NSID NSIDEX BOXID VX VY VZ VXR VYR VZR VXE VYE VZE VXRE VYRE VZRE Remarks INITIAL DESCRIPTION Nodal set ID see NODES containing nodes for initial velocity EQ 0 all nodes are included Nodal set I see SET NODES containing nodes that are exempted from the imposed velocities and may have other initial velocities 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 Initial velocity in x direction Initial velocity in y direction Initial velocity in z direction Initial rotational velocity about the x axis Initial rotational velocity about the y axis Initial rotational velocity about the z axis Initial velocity in x direction of exempted nodes Initial velocity in y direction of exempted nodes Initial velocity in z direction of exempted nodes Initial rotational velocity in x direction of exempted nodes Initial rotational velocity in y direction of exempted nodes Initial rotational velocity in z direction of exempted nodes 1 This generation input must not be used with INITIAL_VELOCITY_GENERATION keyword 2 If a node is initialized on more than one input card set then the last set input will determine its ve
428. re 22 3 The vector is computed as the vector produce X 1 The origin the taile of the normal vector is taken as the corner point of the finite size plane 1 2 3 4 5 6 7 8 Optional Card Required if MOVING is specified after keyword the MOVING option is not compatible with the ORTHO option Variable Default 22 10 RIGIDWALL LS DYNA3D Version 936 RIGIDWALL Optional Card 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 TAURUS Default Remarks 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 All nodes in box are included as slave nodes to rigid wall see DEFINE_ BOX 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 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 co
429. re 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 e It is incrementally objective rigid body rotations do not generate strains allowing for the treatment of finite strains that occur in many practical applications e 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 e A through the thickness thinning option see Hughes and Carnoy 1981 is also available All shells in our current LS DYNA3D 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 originat
430. real time graphics rezoning remapping thermal Parallel versions of LS DYNA3D for shared memory are supported for the SGI and CRAY computers and a distributed memory version of LS DYNA3D has been ported to a subset of the commercially available MPP machines incuding the CRAY T3D IBM 5 1 5 2 and the INTEL PARAGON 1 30 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION SENSE SWITCH CONTROLS The status of an in progress LS DYNA3D 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 DYNA3D which is trapped and the user is prompted to input the sense switch code LS DYNAJ3D has five terminal sense switch controls that are tabulated below Type Response SWI SW2 SW3 SWA SWS A restart file is written and LS DYNA3D terminates LS DYNA3D responds with time and cycle numbers A restart file is written and LS DYNA3D continues A plot state is written and LS DYNA3D continues Enter interactive graphics phase most installations 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 DYNA3D simply type kill 2 psid LS DYNA3D will first look for a file called switch which should contain the sense switch data Otherwise an SW2 is assumed and the output is sent to standard out When LS DYNA3D terminates all scratch f
431. rface contact types An additional flag must be set see THKCHG above if thickness changes are included in the single surface contact algorithms The new contact algorithms that include the shell thickness are relatively recent and are now fully LS DYNA3D Version 936 6 9 CONTROL CONTROL optimized and parallelized The searching in the new algorithms is considerably more extensive and therefore slightly more expensive 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 1 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 where 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 6 10 CONTROL LS DYNA3D Version 936 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 Default
432. rface 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 defintion 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 5 10 CONTACT LS DYNA3D Version 936 CONTACT VARIABLE DESCRIPTION SBOXID BOXID Include only slave nodes segments within specified box see DEFINE BOX in contact definition Nodes shell elements segments parts as defined by SSID are taken MBOXID BOXID Include only master segments within specified box see DEFINE BOX in contact Shell elements segments parts as defined by MSID are taken SPR Include slave side in printed and binary force interface file EQ 1 slave side forces included MPR Include master side in printed and binary force interface file EQ 1 master side forces included FS Static coefficient of friction The functional coefficient is assumed to be dependent on the relative velocity v of the surfaces in contact Dc4v Ho FD e PC FD Dynamic coefficient of friction The functional coefficient is assumed to be dependent on the relative velocity vye of the surfaces in contact 1 He FD FS FD e PC rra DC Exponential decay coefficient The functional coefficient is
433. rfaces 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 hystersis 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 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 and 1993 1994 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 brick shell element 1 6 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION Discrete 3D beam element Generalized dampers Cable modeling Airbag reference geometry Multiple jet model Generalized joint stiffnesses Enh
434. rial Type 70 This special purpose element represents a combined hydraulic and gas filled damper which has a variable orifice coefficient A schematic of the damper is shown in Figure 19 18 Dampers of this type are sometimes used on buffers at the end of railroad tracks and as aircraft undercarriage shock absorbers This material can be used only as a discrete beam element See also notes below Card Format Card 1 1 2 3 4 5 6 7 8 peo fe fm fim foo fom Card 2 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density see also volume in defintion CO Length of gas column Co N Adiabatic constant PO Initial gas pressure PO PA Atmospheric pressure Pa AP Piston cross sectional area Ap KH Hydraulic constant K LS DYNA3D Version 936 19 179 MAT MAT VARIABLE LCID SCLF CLEAR DESCRIPTION Load curve ID see DEFINE CURVE defining the orifice area ao versus element deflection Return factor on orifice force This acts as a factor on the hydraulic force only and is applied when unloading It is intended to represent a valve that opens when the piston unloads to relieve hydraulic pressure Set it to 1 0 for no such relief Scale factor on force Default 1 0 Clearance if nonzero no tensile force develops for positive displacements and negative forces develop only after the clearance is closed As the damper compresses two ac
435. rsions are LS DYNA3D Version 936 L11 INTRODUCTION INTRODUCTION STRUCTURED INPUT TYPE ID KEYWORD NAME BPW WN 5 a 10 SLIDING ONLY SLIDING ONLY PENALTY TIED SURFACE TO SURFACE SURFACE TO SURFACE AUTOMATIC SURFACE TO SURFACE SINGLE SURFACE NODES TO SURFACE AUTOMATIC NODES TO SURFACE TIED NODES TO SURFACE TIED SHELL EDGE TO SURFACE NODES TO SURFACE TIEBREAK SURFACE TO SURFACE ONE WAY SURFACE TO SURFACE AUTOMATIC ONE WAY SURFACE TO SURFACE 13 a 13 14 15 16 17 18 19 20 21 22 23 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 metalforming 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 AUTOMATIC_SINGLE_SURFACE AIRBAG_SINGLE_SURFACE ERODING_SURFACE_TO_SURFACE ERODING_SINGLE_SURFACE ERODING_NODES_TO_SURFACE CONSTRAINT SURFACE TO SURFACE CONSTRAINT NODES TO SURFACE RIGID BODY TWO WAY TO RIGID BODY RIGID NODES TO RIGID BODY RIGID BODY ONE WAY TO RIGID BODY SINGLE EDGE DRAWBEAD CAL
436. s 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 LS DYNA3D Version 936 6 7 CONTROL CONTROL VARIABLE ISLCHK SHLTHK PENOPT THKCHG ORIEN USRSTR 6 8 CONTROL DESCRIPTION Initial penetration check in contact surfaces with indication of initial penetration in output file ISLCHK EQ 0 the default is set to 2 EQ 1 no checking EQ 2 full check of initial penetration is performed 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 comments 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 Penalty stiffness value option For default calculation of the penalty value please refer to the Theoretical Manual EQ 0 the default is set to 1 EQ 1 minimum of master segment and slave node default EQ 2 use master segment stiffness old way EQ 3 use slave node value EQ 4 use slave node va
437. s 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 Set dt for spc reaction forces SWFORC Nodal constraint reaction forces spotwelds 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 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 29 22 RESTART LS DYNA3D Version 936 RESTART Card Format Variable Type 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 LS DYNA3D Version 936 29 23 RESTART 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
438. s 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 OENDMAS Load curve ID that limits the maximum time step size optional Erosion flag for solid and solid shell elements when DTMIN see CONTROL TERMINATIONJis reached If this flag is not set the calculation will terminate EQ 0 no EQ 1 yes 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 6 31 CONTROL DAMPING DAMPING The Keyword options in this section in alphabetical order are DAMPING GLOBAL DAMPING PART MASS DAMPING PART STIFFNESS DAMPING GLOBAL Purpose Define mass weighted nodal damping that applies globally to the nodes of deformable bodies Card Format Default VARIABLE DESCRIPTION LCID Load curve ID which specifies node system damping EQ 0 a contact 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
439. s are recommended to avoid excessive damping Additional cards required for user defined sensor subroutines See Appendix B define only if RBID gt 0 If the rigid body material number is non zero then include 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 LS DYNA3D Version 936 1 3 AIRBAG AIRBAG Card Format Variable Type Default 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 Type Default VARIABLE DESCRIPTION N Number of input parameters not to exceed 25 Cl CN Up to 25 constants user subroutine Additional card required for SIMPLE_PRESSURE_VOLUME option 1 2 3 4 5 6 7 8 Variable Type Default 1 4 AIRBAG LS DYNA3D Version 936 AIRBAG VARIABLE DESCRIPTION CN Constant BETA Scale factor B The relationship is the following CN Relative Volume Pressure Current Volume Relative Vol Initial Volume The pressure is then a function of the ratio of current volume to the initial volume The constant CN is used to establish a relationship known from the literature The scale factor p 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 ma
440. s 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 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 EQ 1 energy dissipation is not computed default 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 eneryg 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 6 16 CONTROL LS DYNA3D Version 936 CONTROL CONTROL HOURGLASS Purpose Reset the default values of the hourglass control Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION THQ Default hourglass viscosity type EQ 1 standard LS DYNA3D EQ 2 Flanagan Belytschko integration EQ 3 Flanagan Belytschko with exact volume integration EQ 4 stiffness form of type 2 Flanagan Belytschko EQ 5 sti
441. s deleting contacts materials elements switching materials from rigid to deformable deformable to rigid etc RIGID 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 modeled 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 LS DYNA3D Version 936 L17 INTRODUCTION 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 which 1s 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 1 18 INTRODUCTION 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 Obption CONTROL HOURGLAS
442. s the corresponding component of stress here Sij is the second Piola Kirchhoff stress tensor The load curve definition that provides the uniaxial data should give the change in gauge length AL and the corresponding force In compression both the force and the change in gauge length must be specified as negative values In tension the force and change in gauge length should be input as positive values The principal stretch ratio in the uniaxial direction is then given by i Lo AL Lo Alternatively the stress versus strain curve can also be input by setting the gauge length thickness and width to unity and defining the engineering strain in place of the change in gauge length and the nominal engineering stress in place of the force see Figure 19 9 The least square fit to the experimental data is performed during the initialization phase and is a comparison between the fit and the actual input is provided in the printed file It is a good idea to visually check the fit to make sure it is acceptable The coefficients 20 are also printed in the output file 19 98 MAT LS DYNA3D Version 936 MAT MAT LAMINATED GLASS This is Material Type 32 With this material model a layered glass including polymeric layers can be modeled Failure of the glass part is possible See notes below Card Format Card 1 1 2 3 4 5 6 7 8 Type Card 2 Type Card Format Define 1 4 cards with a maximum of 32
443. s with Model 27 we find that the results obtained with this model are nearly identical with those of Material 27 as long as large values of Poisson s ratio are used LS DYNA3D Version 936 19 193 MAT MAT MAT OGDEN RUBBER This is also Material Type 77 This material model provides the Ogden 1984 rubber model combined optionally with linear viscoelasticity as outlined by Christensen 1980 Card Format Card 1 1 2 3 4 5 6 7 8 Type Cards 2 and 3 Define the following constants for the Ogden model Card Format Card 2 1 2 3 4 5 6 7 8 Type Card 3 1 2 3 4 5 6 7 8 ALPHA ALPHA2 ALPHA3 ALPHA4 5 ALPHA7 ALPHA8 19 194 MAT LS DYNA3D Version 936 MAT Card Format for Viscoelastic Constants Up to 6 cards may be input A keyword card with a in column 1 terminates this input if less than 6 cards are used Optional Cards VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density PR Poissons ratio 2 49 is recommended smaller values may not work and should not be used MUi the ith shear modulus i varies up to 8 See discussion below ALPHAi i the ith exponent i varies up to 8 See discussion below GI Optional shear relaxation modulus for the ith term BETAI Optional decay constant if ith term Rubber is generally considered to be fully incompressible since the bulk modulus greatly exceeds the shear modulus in
444. 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 16 3a and 16 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 s coordinate of integration point t coordinate of integration point Weighting factor A i e the area associated with the integration point ri divided by actual cross sectional area A s see Figure 16 2 LS DYNA3D Version 936 INTEGRATION 4 Thicknesses defined on beam cross section cards A Relative Area Figure 16 1 Definition of relative area for user defined integration rule Figure 16 2 Definition of integration points for user defined integration rule The input for standard beam section types is defined below In Figures 16 3a and 16 3b the dimensions are
445. ses a completely redesigned highly parallel contact algorithm contact options currently supported include CONTACT_AUTOMATIC_NODES_TO_SURFACE CONTACT_AUTOMATIC_ONE_WAY_SURFACE_TO_SURFACE CONTACT AUTOMATIC SINGLE SURFACE CONTACT_AUTOMATIC_SURFACE_TO_SURFACE e CONTACT NODES TO SURFACE CONTACT_ONE_WAY_SURFACE_TO_SURFACE CONTACT SINGLE SURFACE CONTACT_SURFACE_TO_SURFACE CONTACT_TIED_NODES_TO_SURFACE CONTACT_TIED_SURFACE_TO_SURFACE Due to the nature of the algorithm it is desirable for all contact materials to have a proper positive thickness associated with them This is not required however insofar as the oriented contact segment options have been implemented That is to say for contact types other than 4 and 13 which always require thickness contact surface orientation will be used if SHLTHK 0 on the CONTROL_CONTACT keyword card Also see Control Card 15 columns 26 30 of the structured input manual This allows for O thickness contact interfaces If contact thickness is considered then negative thicknesses can be applied via the Sliding Interface control cards although this not recommend In order for the automatic orientation to work properly the master and slave sides of the contact interface should start in a near contact position such as most material forming problems If the surfaces are initially far apart it is the responsibility of the user to properly orient the contact seg
446. set ID to be moved by interface file IFID Interface ID in interface file 17 4 INTERFACE LS DYNA3D Version 936 INTERFACE INTERFACE JOY Purpose Define an interface for linking calculations by moving a nodal interface Card Format Type VARIABLE DESCRIPTION SID Nodal set ID see NODE LS DYNA3D Version 936 17 5 INTERFACE INTERFACE 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 Card Format Type VARIABLE DESCRIPTION PSID Part set ID for springback see SET PART Define a list of nodal points that are constrained for the springback This section is terminated by an indicating the next input section Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NID Node ID see NODE 17 6 INTERFACE LS DYNA3D Version 936 INTERFACE VARIABLE TC RC LS DYNA3D Version 936 DESCRIPTION Tranlational Constraint EQ 0 EQ 1 EQ 2 EQ 3 EQ 4 EQ 5 EQ 6 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 Rotational constraint EQ 0 EQ 1 EQ 2 EQ 3 EQ 4 EQ 5 EQ 6 EQ 7 no constraints constrained x rotation constrained y rotation constrained z rotation
447. so see CONSTRAINED RIGID BODIES Card Format Type VARIABLE DESCRIPTION PID Part ID see PART 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 RC Rotational constraint 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 rotations EQ 5 constrained y and z rotations EQ 6 constrained z and x rotations EQ 7 constrained x y and z rotations 29 6 RESTART LS DYNA3D Version 936 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 PID LCMAX LCMIN PSIDMX PSIDMN LCVMNX DIR Card 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
448. 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 36 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION RESTART ANALYSIS The LS DYNAS3D 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 a numerical pr
449. ss 19 84 MAT LS DYNA3D Version 936 MAT MAT MOONEY RIVLIN RUBBER This is Material Type 27 A two parametric material model for rubber can be defined Card Format Card 1 1 2 3 4 3 6 7 8 Card 2 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density PR Poisson s ratio gt 49 is recommended smaller values may not work A Constant see literature and equations defined below B Constant see literature and equations defined below If A B 0 0 then a least square fit is computed from tabulated uniaxial data via a load curve The following information should be defined SGL Specimen gauge length lo see Figure 19 8 SW Specimen width see Figure 19 8 ST Specimen thickness see Figure 19 8 LCID Load curve ID see DEFINE_CURVE giving the force versus actual change AL in the gauge length See also Figure 19 9 for an alternative definition LS DYNA3D Version 936 19 85 MAT MAT The strain energy density function is defined as W 1 3 3 C I 1 D 1 2 where C 05A B _ A 5v 2 110 5 2 1 2 D V Poisson s ratio 2 A B shear modulus of linear elasticity I IL invariants of right Cauchy Green Tensor The load curve definition that provides the uniaxial data should give the change in gauge length AL versus the corresponding force In compression both the force and the change in gauge lengt
450. ss flow is assumed A typical application is the modeling of air in automobile tires Additional cards required for SIMPLE AIRBAG MODEL option Card 1 1 2 3 4 5 6 7 8 2 LS DYNA3D Version 936 1 5 AIRBAG AIRBAG 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 lul is the load curve number defining the shape factor as a function of absolute pressure A Exit area A GE 0 0 A is the exit area and is constant in time LT 0 0 1 is the load curve number defining the exit area as a function of absolute pressure PE Ambient pressure pe RO Ambient density p LOU Optional load curve ID giving mass flow out versus gauge pressure in bag See DEFINE CURVE The gamma law equation of state used to determine the pressure in the airbag p v Upe 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 y 2 Cy From conservation of mass the time rate of change of mass flowing into the bag is given as 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 LO
451. ss 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 Card Format Card 1 2 3 4 5 6 7 wis 9 1 Card 2 1 2 3 4 5 6 7 8 LS DYNA3D Version 936 5 19 CONTACT CONTACT Card 3 1 2 3 4 5 6 7 8 Card 4 1 2 3 4 5 6 7 8 Card 5 1 2 3 4 5 6 7 8 5 20 CONTACT LS DYNA3D Version 936 CONTACT 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 EQ 6 CAL3D MADYMO Plane see Appendix F EQ 7 CAL3D MADYMO Hllipsoid see Appendix F EQ 8 VDA surface see Appendix J 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 SSID Slave set ID see SET NODE OPTION PART or SET PART SSTYP Slave set type EQ 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 0 no damping GT 0 viscous damping in percent of critical e g 20 for 20
452. ssenger s side bag LS DYNA3D Version 936 1 15 AIRBAG AIRBAG Jet Focal Point Figure 1 2 Multiple jet model for driver s side airbag Relative jet velocity y degrees cutoff angle Figure 1 3 Normalized jet velocity versus angle for multiple jet driver s side airbag 1 16 AIRBAG LS DYNA3D Version 936 AIRBAG Additional card required for LOAD CURVE option Default VARIABLE DESCRIPTION STIME Time at which pressure is applied The load curve is offset by this amount LCID Load curve ID defining pressure versus time see DEFINE CURVE Within this simple model the control volume is inflated with a pressure defined as a function of time The pressure is uniform throughout the control volume Additional card required for LINEAR FLUID option 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION BULK K bulk modulus of the fluid in the control volume RO p density of the fluid LCID F t input flow curve defining mass per unit time see DEFINE CURVE LS DYNA3D Version 936 1 17 AIRBAG AIRBAG Pressure is determined from P t tO VO where P t Pressure V t Volume of fluid in compressed state M t Tue Vo t Vo t w Volume of fluid in uncompressed state M t 0 current fluid mass M 0 V 0 p mass of fluid at time zero P 0 20 This model is for the simulation of hydroforming processes or similar problems The pressure is controlled by the mass flowing into the volume and
453. ssure load over one triangular or quadrilateral segment defined by four nodes The pressure convention follows Figure 18 3 Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION LCID Load curve ID see DEFINE CURVE SF Load curve scale factor AT Arrival time for pressure or birth time of pressure N1 Node Number N2 Node Number N3 Node Number N4 Node Number 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 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled 3 Triangular segments are defined by repeating the third node 18 16 LOAD LS DYNA3D Version 936 LOAD LOAD SEGMENT SET Purpose Apply the distributed pressure load over each segment in a segment set The pressure convention follows Figure 18 3 Card Format 1 2 3 4 5 6 7 8 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 The load curve multipliers may be used to increase or decrease the pressure The time value is not scaled LS DYNA3D Version 936 18 17 LOAD LOAD n2 Figure 18 3 Nodal numbering for pressure cards Positive pressur
454. sume an analysis is run using the input file jobl inf 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 DYNA3D 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 DYNA3D 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 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 elemen
455. sus relative translational velocity LCIDRDR Load curve ID defining rotational damping moment resultant about local r axis versus relative rotational velocity LCIDRDS Load curve ID defining rotational damping moment resultant about local s axis versus relative rotational velocity LCIDRDT Load curve ID defining rotational damping moment resultant about local t axis versus relative rotational velocity For null load curve ID s no forces are computed The formulation of the discrete beam type 6 assumes that the beam is of zero length and requires no orientation node A small distance between the nodes joined by the beam is permitted The local coordinate system which determines r s t is given by the coordinate ID see DEFINE COORDINATE OPTION in the cross sectional input see SECTION BEAM where the global system is the default SAPrPerawnanx DISPLACEMENT Figure 19 14 resultant forces and moments are determined by a table lookup The origin of the load curve is at 0 0 and tension and compression are similarly treated 19 168 MAT LS DYNA3D Version 936 MAT MAT NONLINEAR PLASTIC DISCRETE BEAM This is Material Type 68 This material model is defined for simulating the effects of nonlinear elastoplastic linear viscous behavior of zero length beams by using six springs each acting about one of the six local degrees of freedom Translational rotational stiffness and damping effects can be considered The plast
456. t If zero friction is inactive for D 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 the load curve ID defining the yield moment versus p rotation see Figure 4 7 Stop angle in degrees for 0 rotation where 0 amp 7 Ignored if zero Stop angle in degrees for negative B rotation Ignored if zero Stop angle in degrees for positive rotation Ignored if zero LS DYNA3D Version 936 4 19 CONSTRAINED CONSTRAINED 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 4 20 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED Figure 4 7 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 y are initialized and torques will develop instantaneously based on the defined load curves The angle p is also initialized but no torque will develop about the local axis on which D
457. t This model is available for perfect plasticity or kinematic hardening for a bi lmear von Mises model The implementation is described in Whirley Hallquist and Goudreau 1989 Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification RO Density E Young s modulus PR Poisson s ratio SIGY Yield stress ETAN Plastic tangent modulus LS DYNA3D Version 936 19 95 MAT MAT MAT FRAZER NASH RUBBER MODEL This is Material Type 31 This model defines rubber from uniaxial test data It is a modified form of the hyperelastic constitutive law first described in Kendington 1988 See also the notes below Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be defined RO Mass density PR Poisson s ratio Values between 49 and 50 are suggested C100 C100 EQ 1 0 if term is in the least squares fit C200 C200 EQ 1 0 if term is in the least squares fit 19 96 MAT LS DYNA3D Version 936 VARIABLE C300 C400 C110 C210 C010 C020 EXIT EMAX EMIN SGL SW ST LCID MAT DESCRIPTION C300 EQ 1 0 if term is in the least squares fit C400 EQ 1 0 if term is in the least squares fit C110 EQ 1 0 if term is in the least squares fit C210 EQ 1 0 if term is in the least squares fit EQ 1 0 if term is in the least squares fit Coo EQ 1 0 if term is in
458. t 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 termi nation will occur if a rigid body node is used in a spring definition where deflection is limited LS DYNA3D Version 936 23 7 SECTION SECTION SECTION SEATBELT Purpose Define section properties for the seat belt elements This card is required for the PART Section Currently nothing but the ID is required Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION SECID Section ID 23 8 SECTION LS DYNA3D Version 936 SECTION SECTION SHELL Purpose Define section properties for shell elements Card Format Card 1 3 4 6 7 8 Card 2 1 2 3 4 5 6 7 8 Optional Section Cards if ICOMP 1 Define NIP angles putting 8 on each card Cards 3 4 1 2 3 4 5 6 7 8 fom fom ome om fom VARIABLE DESCRIPTION SECID Section ID SECID is referenced on the PART card and must be unique LS DYNA3D Version 936 23 9 SECTION SECTION VARIABLE DESCRIPTION ELFORM Element formulation options EQ 1 Hughes Liu EQ 2 Belytschko Tsay default 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
459. t tension value is not always achieved 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 lO0mm 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 return 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 1 When the retractor has fed L into el where crit Lerit fed length 1 1 minimum length minimum length defined on belt material input fed length
460. t to zero if LCCP23 is defined below LS DYNA3D Version 936 1 9 AIRBAG AIRBAG VARIABLE LCCP23 AP23 LCAP23 PE RO GC LCEFR POVER PPOP IOC IOA IVOL IRO IT LCBF DESCRIPTION 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 Ambient density Gravitational conversion constant mandatory no default If consistent units are being used for 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 Relative pressure gauge for initiating exit flow Ppop Inflator orifice coefficient Inflator orifice area Inflator volume Inflator density Inflator temperature Load curve defining burn fraction versus time The gamma law equation of state for the adiabatic expansion of an ideal gas is used to determine the pressure after preload p y 1 pe 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 DYNA3D Version 936 AIRBAG A pressure relation is defined p Qa P2
461. t with some identical or unique attributes Card Format Variable Default Cards 2 3 4 OPTION LIST The next card terminates the input 1 2 3 4 5 6 7 8 NIDI NID2 NID3 NID4 NID5 NID6 NID7 NID8 24 4 SET LS DYNA3D Version 936 SET Cards 2 3 4 OPTIONZCOLUMN The next card terminates the input 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 DA4 Fourth nodal attribute default value NIDN Node ID n NID Nodal ID Al First nodal attribute see remark 2 below A2 Second nodal attribute A3 Third nodal attribute A4 Fourth nodal attribute Remarks 1 Nodal attributes can be assigned for some input types For example for contact option CONTACT TIEBREAK NODES TO SURFACE the attributes are DA1 NFLF Normal failure force DA2 NSFLF Shear failure force DA3 NNEN Exponent for normal force DA4 NMES Exponent for shear force 2 The default nodal attributes can be overridden on these cards otherwise 1 etc LS DYNA3D Version 936 24 5 SET SET SET PART OPTION Available options include LIST COLUMN Purpose Define a set of parts with optional attributes For the column option see AIRBAG or CONSTRAINED RIGID BODY STOPPERS Card Format Variable Default Remark
462. ted 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 DYNA3D 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 and D3THDT files see also the DATABASE EXTENT BINARY definition It is possible to severely restrict the information that is dumped and consequently reduce the size of the databases The contents of the D3THDT file 8 4 DATABASE LS DYNA3D Version 936 DATABASE 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 Card Format 1 2 3 4 3 6 7 8 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 will cause plot dumps to be written at the convergence check interval specified on the CONTROL_DYNAMIC_RELAXATION card If this file is not specified on the execution line command line see INTRODUCTION EXECUTION SYNTAX it will not be created LCDT Optional load curve ID specifying time interval between dumps This option is only av
463. terial strength in crashfront elements default 1 0 Softening for fiber tensile strength EQ 0 0 fiber rupture with tension cutoff GT 0 0 stress FBRT after failure Shear strength ab plane see below Longitudinal tensile strength see below Transverse tensile strength b axis see below Transverse compressive strength b axis see below 22 LS DYNA3D Version 936 MAT VARIABLE DESCRIPTION ALPH Shear stress parameter for the nonlinear term see Material 22 CRIT Failure criterion material number EQ 54 0 Chang matrix failure criterion as Material 22 default EQ 55 0 Tsai Wu criterion for matrix failure The Chang Chang criteria is given as follows for the tensile fiber mode 2 2 0 failed Buc wn ee BRE ap Sa qe X Sc 0 elastic Eq Ep Gab Vba Vab 9 for the compressive fiber mode Oaa lt 0 then 2 2 O4 f 0 failed Xe lt 0 elastic Vba Vab 0 for the tensile matrix mode 2 2 2 0 failed Opp gt 0 then al si 4 lt 0 elastic 0 2 0 and for the compressive matrix mode 2 2 2 Opp O0 then 4 fo 192 Sab _ 25 25 Y Sc 0 elastic C b Vba Vab 9 0 X 2Y 50 fiber volume LS DYNA3D Version 936 19 141 MAT MAT In the Tsay Wu criteria the tensile and compressive fiber modes are treated as in Chang and Chang The failure cri
464. terion for the tensile and compressive matrix mode is given as 2 oz 0 0 _ 29 failed ia Y Y Se Y Y lt 0 elastic For 1 we get the original criterion of Hashin 1980 For 0 we get the maximum stress criterion which is found to compare better to experiments Tensile failure for each lamina can be brittle as indicated above if FBRT is set to 0 0 However improved results are reported if the failed lamina carries the failure load or at least some part of it until the entire laminate cross section fails Then FBRT is set to be larger than zero With the value SOFT a degradation in strength is assumed for compression failure If SOFT is set to be smaller than one then the strength of the elements in the near neighborhood to the failed elements are multipled by the value of SOFT This crudely accounts for the damage that occurs prior to failure and the tracking of the crashfront 19 142 MAT LS DYNA3D Version 936 MAT MAT LOW DENSITY FOAM This is Material Type 57 It is mainly for Modeling Low Density Urethane Foam which is highly compressible Its main applications are for seat cushions and padding on the Side Impact Dummies SID Optionally a tension cut off failure can be defined Also see the notes below Card Format Card 1 1 2 3 4 5 Card 2 SHAPE FAIL VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus LS DY
465. termined by element nodes nj n2 and n4 as shown in Figure 19 1 EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center EQ 2 0 globally orthotropic with material axes determined by vectors defined below EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector defined below with the shell normal vector Material axes change flag for brick elements Define coordinates of point p for AOPT 1 Define components of vector a for AOPT 2 Define components of vector v for AOPT 3 Define components of vector d for AOPT 2 EQ 1 0 default EQ 2 0 switch material axes a and b EQ 3 0 switch material axes a and c Time step for automatic element deletion Nonlinear shear stress parameter Softening reduction factor for strength in crush Softening of fiber tensile strength sr reduction factor default 0 447 sf softening factor default 0 0 Longitudinal compressive strength a axis Longitudinal tensile strength a axis Transverse compressive strength b axis Transverse tensile strength b axis Shear strength ab plane GT 0 0 faceted failure surface theory LT 0 0 ellipsoidal failure surface theory 19 149 MAT MAT MAT ELASTIC WITH VISCOSITY This is Materi
466. th material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elements only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector EQ 4 0 locally orthotropic in cylindrical coordinate system with the material axes determined by a vector v and an orginating point P They define the axis of symmetry XP YP ZP Xp Yp Zp define coordinates of point p for AOPT 1 and 4 ALA2 A3 a2 define components of vector a for AOPT 2 D1 D2 D3 d 42 d3 define components of vector d for AOPT 2 VLV2 V3 V1 V2 V3 define components of vector v for AOPT 3 and 4 PSI Material angle for AOPT 3 which may be overridden on the element card see ELEMENT SHELL The material law that relates stresses to strains is defined as C T C T epe where T is a transformation matrix and C is the constitutive
467. the stiffness values are too low or zero the stop will be violated Figure 4 5 Definition of angles for the generalized joint stiffness The magnitude 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 4 16 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED Figure 4 6 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 LS DYNA3D Version 936 4 17 CONSTRAINED CONSTRAINED Card Format 2 of 4 Required for FLEXION TORSION stiffness Card 2 1 2 3 4 5 6 Variable LCIDAL LCIDG LCIDBT DLCIDAL DLCIDG DLCIDBT 1 Default Card Format 3 of 4 Required for FLEXION TORSION stiffness Card 3 1 2 3 4 Default Card Format 4 of 4 Required for FLEXION TORSION stiffness Card 4 1 2 3 4 18 CONSTRAINED LS DYNA3D Version 936 VARIABLE LCIDAL LCIDG LCIDBT DLCIDAL DLCIDG DLCIDBT ESAL FMAL ESBT FMBT SAAL NSABT PSABT CONSTRAINED DESCRIPTION Load curve ID for moment versus rotation in radians See Figure 4 7 where it should be noted that 0 S amp S If zero the applied moment is set to zero See DEFINE CURVE Load curve ID
468. the assumption of plastic flow in the direction normal to the yield surface produces a plastic strain rate vector that has a component in the volumetric hydrostatic direction see Figure 19 6 In models such as the Drucker Prager and Mohr Coulomb this dilatency continues as long as shear loads are applied and in many cases produces far more dilatency than is experimentally observed in material tests In the cap model when the failure surface is active dilatency is produced just as with the Drucker Prager and Mohr Columb models However the hardening law permits the cap surface to contract until the cap intersects the failure envelope at the stress point and the cap remains at that point The local normal to the yield surface is now vertical LS DYNA3D Version 936 19 75 MAT MAT and therefore the normality rule assures that no further plastic volumetric strain dilatency is created Adjustment of the parameters that control the rate of cap contractions permits experimentally observed amounts of dilatency to be incorporated into the cap model thus producing a constitutive law which better represents the physics to be modeled Another advantage of the cap model over other models such as the Drucker Prager and Mohr Coulomb is the ability to model plastic compaction In these models all purely volumetric response is elastic In the cap model volumetric response is elastic until the stress point hits the cap surface Therefore plastic volume
469. the constitutive model with respect to a set of directors whose direction is defined by the plastic deformation Bammann and Aifantis 1987 Bammann and Johnson 1987 Decomposing both the skew symmetric and symmetric parts of the velocity gradient into elastic and plastic parts we write for the elastic stretching D and the elastic spin W we w wPe Within this structure it is now necessary to prescribe an equation for the plastic spin W in addition to the normally prescribed flow rule for DP and the stretching due to the thermal expansion Dt As proposed we assume a flow rule of the form E 3 vr 161 where is the temperature is the scalar hardening variable and 5 is the difference between the deviatoric Cauchy stress o and the tensor variable a E f T Y T V T scalar functions whose specific dependence upon the temperature is given below Assuming isotropic thermal expansion and introducing the expansion coefficient the thermal stretching can be written ATI The evolution of the internal variables and are prescribed in a hardening minus recovery format as LS DYNA3D Version 936 19 129 MAT MAT H T D Ry T D R where h are the hardening moduli rs T and Rg T are scalar functions describing the diffusion controlled static or ther
470. the interface segment file created in the first run should be specified using the L parameter on the LS DYNA3D 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 DYNA3D s analysis capability LS DYNA3D Version 936 1 27 INTRODUCTION INTRODUCTION A shells IANA 0 trusses beams springs lumped masses Figure L2 Elements in LS DYNA3D 1 28 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION 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 DYNA3D calculations may have 10 000 to 200 000 elements Memory allocation is dynamic and can be controlled during execution LS DYNA3D Version 936 1 29 INTRODUCTION INTRODUCTION CODE ORGANIZATION LS DYNA3D consists of one source that compiles under FORTRAN compilers on most UNIX workstations and supercomputers The programming follows the FORTRAN 77 standard with some parts programmed in C LS DYNA3D has eight segments in the main code They are input restart initialization solution interactive
471. the reference frequency in radians per second For example if 1 damping at 2Hz is required 19 92 MAT LS DYNA3D Version 936 MAT _ 2 0 01 2 2 X 0 001592 If damping is used a small timestep may be required LS DYNA3D does not check this so to avoid instability it may be necessary to control the timestep via a load curve As a guide the timestep required for any given element is multiplied by 0 3L c when damping is present L element length c sound speed Moment Interaction Plastic hinges can form due to the combined action of moments about the three axes This facility is activated only when yield moments are defined in the material input A hinge forms when the following condition is first satisfied 2 2 2 Mr pl Ms gc gt I M wield M syield M yield Mr Ms M current moment Mryield Msyield Mtyield yield moment where Note that scale factors for hinge behavior defined in the input will also be applied to the yield moments for example Mgyjelq in the above formula is given by the input yield moment about the local axis times the input scale factor for the local s axis For strain softening characteristics the yield moment should generally be set equal to the initial peak of the moment rotation load curve On forming a hinge upper limit moments are set These are given by Tupper M MAX and similar for and My Thereafter the plastic moments will be g
472. tial slack length LS DYNA3D Version 936 11 7 ELEMENT 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 Default VARIABLE DESCRIPTION SBACID Accelerometer ID A unique number has to be used NIDI Node 1 ID NID2 Node 2 ID NID3 Node 3 ID 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 z perpendicular to the plane containing nodes 1 2 and 3 z x x a where a is from node 1 to node 3 e localy zxx The three nodes should all be part of the same rigid body The local axis then rotates with the body 11 8 ELEMENT LS DYNA3D Version 936 ELEMENT ELEMENT SEATBELT PRETENSIONER Purpose Define seat belt pretensioner A combination with sensors and retractors is also possible Card Format Variable SBPRID SBPRTY SBSIDI SBSID2 SBSID3 SBSID4 Type Default Remarks Second Card Variable SBRID TIME PTLCID Type Default VARIABLE DESCRIPTION SBPRID Pretensioner ID Use consecutive numbering see below SBPRTY Pretensioner type EQ 1 pyrotechnic retractor EQ 2 pre loaded spring becomes active EQ 3 lock spring removed LS DYNA3D Version
473. ting a rigid wall 1 160 nodes 1 369 solids 972 cycle time 217 shells 0 cycles 5 500 normalized 6 2 Impact of a cylinder into a rail 27 560 nodes 5 128 solids 3 667 cycle time 208 shells 0 cycles 36 200 normalized 5 9 Square plate impacted by a rod 14 590 nodes 6 856 solids 1 3550 cycle time 194 shells 4 824 cycles 12 200 normalized 6 3 Box beam buckling 47 880 nodes 1 911 solids 0 cycle time 380 shells 1 800 cycles 70 000 normalized 6 2 Trim saw drop Black amp Decker 168 510 nodes 12 381 solids 1 140 cycle time 320 shells 10 726 cycles 44 420 normalized 5 8 Dual airbag dummy crash 127 060 nodes 25 502 solids 5 594 cycle time 277 shells 17 757 cycles 19 670 normalized 6 0 Megabyte of RAM 22 Megabyte of RAM PC 32 P5 90 476 89 25 11 960 90 25 6 030 80 22 3 17 780 141 255 76 740 146 2 6 54 780 119 2 6 PC 16 P5 120 342 64 1 8 8 420 63 1 8 4 450 59 1 9 14 530 115 1 9 54 590 103 1 9 43 500 37 510 95 82 2 1 1 8 PC 32 P5 166 278 52 1 5 6 750 51 1 5 3 590 48 1 5 11 430 91 1 5 44 240 84 1 5 34 650 75 1 6 PC 64 P6 200 126 24 0 68 2 950 22 0 63 1 690 22 0 71 5 120 41 0 67 20 900 23 140 40 44 0 73 0 8 16 160 21 280 35 46 0 76 1 0 IBM 128 RS 6000 550 342 78 p 9 860 74 Dil 4 300 57 1 8 14 390 114 1 9 48 330 92 1 7 37 490 82 1 8 HP 32 715 Mod33
474. ting shell response Card Format WRPANG ITRIST IRNXX ISTUPD THEORY BWC MITER fete 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 ITRIST Automatic sorting of triangular shell elements to treat degenerate quadrilateral shell elements as CO triangular shells see option THEORY below EQ 1 full sorting EQ 2 no sorting required default IRNXX Hughes Liu shell normal update option EQ 2 unique nodal fibers Good to model shell edges EQ 1 compute normals each cycle recommended EQ 0 default set to 1 EQ 1 compute on restarts EQ n compute every n cycles ISTUPD Shell thickness change option EQ 0 no change EQ 1 membrane straining causes thickness change Important in sheetmetalforming 6 20 CONTROL LS DYNA3D Version 936 CONTROL VARIABLE THEORY BWC MITER DESCRIPTION Shell theory EQ 1 Hughes Liu EQ 2 Belytschko Tsay default EQ 3 BCIZ triangular shell not recommended 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 Englemann Whirley shell EQ 9 fully integrated Belytschko Tsay membrane EQ 10 Belytschko Wong Chiang recommended EQ 11 Fast co rotational Hughes Liu Warping stiffness for Belytschko Tsay shells EQ 1 Belytschko Wong Chiang warping stiffness adde
475. tion at node nj Note that the thickness defined on the BEAM_ ELEMENT_THICKNESS card overrides the definition give here TS2 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 nq TT2 Beam thickness CST 0 0 2 0 or inner diameter CST 1 0 in t direction at node n NSLOC 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 side at s 1 0 NTLOC 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 A Cross sectional area The definition on BEAM ELEMENT THICKNESS overrides the value defined here see Figure 23 1 ISS I The definition on BEAM ELEMENT THICKNESS overrides the value defined here see Figure 23 1 LS DYNA3D Version 936 23 3 SECTION SECTION VARIABLE ITT IRR SA VOL INER CID CA OFFSET Remark DESCRIPTION It The definition on ELEMENT THICKNESS overrides the value defined here see Figure 23 1 J polar inertia The definition on ELEMENT THICKNESS overrides the value defined here see Figure 23 1 Shear area The definition on BEAM ELEMENT THICKNESS overrides the value defined here see Figure 23 1 Volume of discrete beam I lumped inertia of d
476. tion 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 keyword 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 _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 hemis
477. tion 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 WaalOs 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 Since 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 Fe203 driver airbag propellant The deflagration model its implementation and the results for the ICI propellant are presented in Hallquist et al
478. tions contribute to the force developed First the gas is Figure 19 18 Schematic of Hydraulic Gas damper adiabatically compressed into a smaller volume Secondly oil is forced through an orifice profiled pin may occupy some of the cross sectional area of the orifice thus the orifice area available for the oil varies with the stroke The force is assumed proportional to the square of the velocity and inversely proportional to the available area 19 180 MAT LS DYNA3D Version 936 MAT The equation for this element is 2 n F 5 ndz nats P where S is the element deflection and V is the relative velocity across the element LS DYNA3D Version 936 19 181 MAT MAT MAT CABLE DISCRETE BEAM This is Material Type 71 This model permits elastic cables to be realistically modelled thus no force will develop in compression Card Format Card 1 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density see also volume in SECTION BEAM definition E Young s modulus LCID Load curve ID see DEFINE CURVE defining the stress versus engineering strain Optional The force F generated by the cable is nonzero if and only if the cable is tension The force is given by F K max AL 0 where AL is the change in length AL current length initial length offset and the stiffness is defined as E area initial
479. tions the wall can be moved in the direction V as shown LS DYNA3D Version 936 22 7 RIGIDWALL RIGIDWALL RIGIDWALL PLANAR OPTION OPTION OPTION Available options include 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 1 the ORTHO card is first the FINITE definition card below must preceed the MOVING definition card and the FORCES definition card should 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 Card 1 1 2 3 4 5 6 7 8 Default 22 8 RIGIDWALL LS DYNA3D Version 936 RIGIDWALL Card 2 1 2 3 4 5 6 7 8 Optional 2 Cards Required if ORTHO is specified after the keyword See Figure 22 2 for the definition of orthotropic friction 1 2 3 4 5 6 LS DYNA3D Version 936 22 9 RIGIDWALL RIGIDWALL Optional Card Required if FINITE is specified after the keyword See Figu
480. tment of Injury Prevention The Hague The Netherlands 1990 Maker B N Private communication Lawrence Livermore National Laboratory Dr Maker programmed and implemented the compressible Mooney Rivlin rubber model 1987 Matzenmiller A and J K Schm Crashworthiness Considerations of Composite Structures A First Step with Explicit Time Integration in Nonlinear Computational Mechanics State of the Art Ed P Wriggers W Wagner Springer Verlay 1991 Neilsen M K H S Morgan and R D Krieg A Phenomenological Constitutive Model for Low Density Polyurethane Foams Rept SAND86 2927 Sandia National Laboratories Albuquerque N M 1987 Papadrakakis M Method for the Automatic Evaluation of the Dynamic Relaxation Parameters Comp Meth Appl Mech Eng Vol 25 1981 pp 35 48 Pelessone D Private communication GA Technologies P O Box 85608 San Diego CA Telephone No 619 455 2501 1986 Sackett S J Geological Concrete Model Development Private Communication 1987 Sandler I S and D Rubin An Algorithm and a Modular Subroutine for the Cap Model Int J Numer Analy Meth Geomech 3 pp 173 186 1979 Schwer L E W Cheva and J O Hallquist A Simple Viscoelastic Model for Energy Absorbers Used in Vehicle Barrier Impacts in preparation LS DYNA3D Version 936 30 5 REF REFERENCES Simo J C J W Ju K S Pister and R L Taylor An Assessment o
481. to 3 then you will not get mid surface results Set to 1 to dump strain tensors for solid shell and thick shell elements for plotting by LS TAURUS 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 singe strain tensor is written Flag for including stress tensor in the shell LS TAURUS database EQ 1 include default EQ 2 exclude Flag for including stress tensor in the shell LS TAURUS database EQ 1 include default EQ 2 exclude Flag for including the effective plastic strains in the shell LS TAURUS database EQ 1 include default EQ 2 exclude Flag for including stress resultants in the shell LS TAURUS database EQ 1 include default EQ 2 exclude Flag for including internal energy and thickness in the LS TAURUS database EQ 1 include default EQ 2 exclude LS DYNA3D Version 936 CMPFLG IEVERP BEAMIP DCOMP SHGE STSSZ LS DYNA3D Version 936 DATABASE Composite material stress output in local coordinate system for shells and solids 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
482. train values exceed the maximum input value ES Effective stress Define up to 16 values If ES and EPS are undefined the yield stress and plastic hardening modulus are taken from SIGY and EH In this case the bilinear stress strain curve shown in Figure 19 2 is obtained with hardening parameter D 1 The yield strength is calculated as The quantity Ep is the plastic hardening modulus defined in terms of Young s modulus E and the tangent modulus E as follows If ES and EPS are specified a curve like that shown in Figure 19 4 may be defined Effective stress is defined in terms of the deviatoric stress tensor Sij aS 19 30 MAT LS DYNA3D Version 936 MAT c 3 1 2 2 Sij Sij and effective plastic strain by 1 2 z 2 ee 20606 where t denotes time and D is the plastic component of the rate of deformation tensor In this case the plastic hardening modulus on Card 1 is ignored and the yield stress is given as oy f e where the value for f e is found by interpolation from the data curve Piecewise linear curve defining the yield stress versus effective plastic strain A nonzero yield stress is Oy defined when the plastic strain is zero Figure 19 4 Effective stress versus effective plastic strain curve LS DYNA3D Version 936 19 31 MAT MAT MAT STEINBERG This is Material Type 11 This material is available for modeling materials deforming at very
483. tric strain compaction is generated at a rate controlled by the hardening law Thus in addition to controlling the amount of dilatency the introduction of the cap surface adds another experimentally observed response characteristic of geological material into the model The inclusion of kinematic hardening results in hysteretic energy dissipation under cyclic loading conditions Following the approach of Isenberg et al 1978 a nonlinear kinematic hardening law is used for the failure envelope surface when nonzero values of and N are specified In this case the failure envelope surface is replaced by a family of yield surfaces bounded by an initial yield surface and a limiting failure envelope surface Thus the shape of the yield surfaces described above remains unchanged but they may translate in a plane orthogonal to the J axis Translation of the yield surfaces is permitted through the introduction of a back stress tensor 4 The formulation including kinematic hardening is obtained by replacing the stress o with the translated stress tensor T o amp in all of the above equation The history tensor is assumed deviatoric and therefore has only 5 unique components The evolution of the back stress tensor is governed by the nonlinear hardening law cF o a e P where c is a constant F is a scalar function of and and e is the rate of deviator plastic strain The constant may be estimated from the slope of the shear
484. ts 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 e Time and output intervals are continuous with jobl i e the time is not reset to zero e 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 e Completely new databases will be generated with the time offset 1 38 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION 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 ac
485. ts only This option determines locally orthotropic material axes by offsetting the material axes by an angle to be specified from a line in the plane of the shell determined by taking the cross product of the vector v defined below with the shell normal vector EQ 4 0 locally orthotropic in cylindrical coordinate system with the material axes determined by a vector v and an orginating point P They define the axis of symmetry XP YP ZP Coordinates of point p for AOPT 1 ALA2 A3 Components of vector a for AOPT z 2 VLV2 V3 Components of vector v for AOPT 3 D1 D2 D3 Components of vector d for AOPT z 2 EAi Young s modulus in a direction at temperature Ti EBi Ep Young s modulus in b direction at temperature Ti ECi Young s modulus in c direction at temperature LS DYNA3D Version 936 19 65 MAT MAT VARIABLE DESCRIPTION PRBAi Poisson s ratio ba at temperature PRCAi Vca Poisson s ratio ca at temperature Ti PRCBi Vcb Poisson s ratio cb at temperature Ti AAi Qa coefficient of thermal expansion in a direction at temperature Ti ABi coefficient of thermal expansion in b direction at temperature Ti ACi Oc coefficient of thermal expansion in c direction at temperature Ti GABi Gap Shear modulus ab at temperature Ti GBCi Shear modulus bc at temperature Ti GCAi Shear modulus ca at temperature Ti Ti ith temperature 19 66 MAT LS DYNA3D Version 936 MAT MAT PIEC
486. ttempt 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 Tw ELEMENT EID PID 1 N2 4 PART PID SID MID EOSID HGID SECTION SHELL SID ELFORM SHRE KIP PROPT QR ICOMP P AME GM MAT ELASTIC MID RQ PR DA DB EOS EOSID HOURGLASS HGID Figure I 1 Organization of the keyword input 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 1 10 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION 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 BE 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 A
487. ual Transverse tensile strength b axis see Theoretical Manual Transverse compressive strength b axis see Theoretical Manual Shear stress parameter for the nonlinear term see Theoretical Manual Suggested range 0 0 5 19 63 MAT MAT MAT TEMPERATURE DEPENDENT ORTHOTROPIC This is Material Type 23 An orthotropic elastic material with arbitrary temperature dependency can be defined Card Format Card 1 1 2 3 4 5 6 7 8 Type Card 2 Type Card 3 Type Define one set of constants on two cards for each temperature point Up to 48 points 96 cards can defined The next card terminates the input Cards 1 for Temperature 19 64 MAT LS DYNA3D Version 936 MAT Cards 2 for Temperature Ti on VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density AOPT Material axes option EQ 0 0 locally orthotropic with material axes determined by element nodes as shown in Figure 19 1 Nodes 1 2 and 4 of an element are identical to the Nodes used for the definition of a coordinate system as by DEFINE COORDINATE NODES EQ 1 0 locally orthotropic with material axes determined by a point in space and the global location of the element center this is the a direction EQ 2 0 globally orthotropic with material axes determined by vectors defined below as with DEFINE COORDINATE VECTOR EQ 3 0 applicable to shell elemen
488. uation of state label AP BP RIP OMCP I First ignition coefficient LS DYNA3D Version 936 12 13 EOS EOS VARIABLE DESCRIPTION G Second ignition coefficient H Growth coefficient AE BE RIE R2E OMCE FCRIT Critical fraction reacted usually 1 0 Z Pressure exponent X Y CP Heat capacity of reaction products CE Heat capacity of unreacted HE M Generally 0 EO Initial energy of HE per unit volume TO Initial temperature A JWL equation of state defines the pressure in the unreacted HE as Q A E OE A RI Ve 126 R2 Ve Rle Ve R2 V V where Ve is the relative volume Ee is the internal energy and the constants Ae Be We Rle and R2 are inputs Similarly the pressure in the reaction products is defined by another JWL form Qo 2 OE 1 p R2 OED RIV R2 V V 12 14 EOS LS DYNA3D Version 936 EOS The mixture of unreacted explosive and reaction products is defined by the fraction reacted no reaction F 1 complete conversion from explosive to products The pressures and temperature are assumed to be in equilibrium and the volumes are assumed to be additive 1 D F Ve FVp The rate of reaction is a 1 FCRIT 7 7 1 v 1 H 1 P 51 1 where I 2 and m generally 0 are input constants The JWL equations of state and the reaction rates have
489. ude the eight values for the coordinate system option if it is nonzero and two values for the bulk and shear modulus Up to ten user subroutines can currently be implemented simultaneously to update the stresses in solids shells thick shells and beam elements A sample subroutine is given in this Appendix for treating an elastic material When implementing plane stress constitutive models for shells and beams the strain increments in the directions of the zero normal stress must be determined In shell elements this is the strain increment EPS 3 which is normal to the midsurface and in beam elements this includes the strain increments EPS 2 and EPS 3 which are normal to the axis These strain increments are used to account for thickness changes A sample subroutine is provided below for treating an elastic material SUBROUTINE UMAT41 CM EPS SIG HISV DT1 CAPA ETYPE TIME Qe ke ee hee e e e e e e e he e e e e k e k k he k e k se k k he k e k k k k k e k k k k k ke k k k k k k k k k k k k k k kk C LIVERMORE SOFTWARE TECHNOLOGY CORPORATION LSTC Q COPYRIGHT 1987 1994 LSTC C ALL RIGHTS RESERVED Qe e e e he e he e e e e e e he e e k e k se k k he k e k se k k he k e k k k k he k k k k k k ke k he k k ISOTROPIC ELASTIC MATERIAL SAMPLE USER SUBROUTINE VARIABLES 1 YOUNG S MODULUS CM 2 POISSON S RATIO EPS 1 LOCAL X STRAIN EPS 2
490. ultiplier 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 A radiation boundary condition is calculated using a radiant heat transfer coefficient Set 4 T where hy is a radiant heat transfer coefficient defined as 2 2 2 h f T T 1 T o 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 for the boundary surface LS DYNA3D Version 936 3 15 BOUNDARY BOUNDARY BOUNDARY SLIDING PLANE Purpose Define a sliding 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 coordinate of vector defining normal or vector VY y coordinate of vector defining normal or vector VZ z coordinate of vector defining normal or vector COPT Option EQ 0 node moves on normal plane EQ 1 node moves only in vector direction 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 magnitud
491. us temperature MLCI Curve multiplier at node see Figure 3 2 MLC2 Curve multiplier at node N2 see Figure 3 2 MLC3 Curve multiplier at node N3 see Figure 3 2 MLC4 Curve multiplier at node N4 see Figure 3 2 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 LS DYNA3D Version 936 3 7 BOUNDARY BOUNDARY By convention heat flow is positive in the direction of the surface outward normal vector Surface definition is in accordance with the right hand rule The outward normal vector points to the right as one progresses from node N1 No N3 N4 See Figure 3 2 n4 n2 nl Figure 3 2 Nodal number determines outward normal 3 8 BOUNDARY LS DYNA3D Version 936 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 modelled Card Format 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 With the two optional switches the influence of reflecting waves can be studied For geomechanical pro
492. use a resultant formulation Data compression to eliminate rigid body data EQ 1 off default no data compression EQ 2 on Output shell hourglass energy EQ 1 off default no hourglass energy written EQ 2 on Output shell element time step EQ 1 off default no shell element time step output EQ 2 on 8 15 DATABASE DATABASE DATABASE HISTORY OPTION Options include BEAM BEAM SET NODE NODE SET SHELL SHELL SET SOLID SOLID SET TSHELL TSHELL SET Purpose Control which nodes or elements are output into the binary history file D3THDT the ASCII file NODOUT and the ASCII file ELOUT Define as many cards as necessary The next card terminates the input See also DATABASE BINARY OPTION DATABASE OPTION Card Format 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 The contents of the files are given in Table 8 1 for nodes Table 8 2 for solid elements Table 8 3 for shells and thick shells and Table 8 4 for beam elements On the binary file D3THDT the contents may be extended or reduced with the DATABASE EXTENT BINARY definition 8 16 DATABASE LS DYNA3D Version 936 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 DA
493. vector can be defined such that m n xl The extent of the stonewall is limited by defining L LENL and M LENM A zero value for either of these lengths indicates that the stonewall is infinite in that direction 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 These four nodes are for visualizing the movement of the wall They move with the wall To view the wall in LS TAURUS it is necessary to define a shell element with these four nodes as its connectivity 22 14 RIGIDWALL LS DYNA3D Version 936 SECTION SECTION In this section the element formulation integration rule nodal thicknesses or cross sectional properties are defined All section identifiers SECID s defined in this section must be unique i e if a number is used as a section ID for a beam then this number cannot be used again even for as a section ID for a solid The keyword cards in this section are defined in alphabetical order SECTION BEAM SECTION DISCRETE SECTION SEATBELT SECTION SHELL SECTION SOLID SECTION SOLID ALE SECTION TSHELL The location and order of these cards in the input file are arbitrary LS DYNA3D Version 936 23 1 SECTION SECTION SECTION BEAM Purpose Define cross sectional properties for beam truss discrete beam and cable elements
494. vector originating on the wall tail and terminating in the body head i e 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 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 18 BOUNDARY LS DYNA3D Version 936 BOUNDARY BOUNDARY TEMPERATURE OPTION Available options are NODE SET Purpose Define temperature boundary conditions for a thermal or coupled thermal structural analysis Card Format Default 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 temperature 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 DYNA3D Version 936 3 19 BOUNDARY BOUNDARY BOUNDARY USA SURFACE Purpose Define a surface for coupling with the USA boundary element code DeRuntz 1993 The outward normal vectors should point into the fluid media Card Format Default VARIABLE DESCRIPTION SSID Segment set ID see SET SEGMENT WETDRY Wet surface flag EQ 0 dry no coupling EQ 1 wet
495. viatoric stresses Pressure is determined by one of ten equations of state including e linear polynomial Woodruff 1973 e JWL high explosive Dobratz 1981 e Sack Tuesday high explosive Woodruff 1973 e Gruneisen Woodruff 1973 e ratio of polynomials Woodruff 1973 e linear polynomial with energy deposition e ignition and growth of reaction in HE Lee and Tarver 1980 Cochran and Chan 1979 e tabulated compaction e tabulated e 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 LS DYNA3D Version 936 1 21 INTRODUCTION INTRODUCTION SPATIAL DISCRETIZATION The elements shown in Figure 1 2 are presently available Currently springs dampers beams membranes shells bricks brick shells and seatbelt elements a
496. with real anisotropic behavior A nonlinear elastoplastic material behavior can be defined separately for all normal and shear stresses These are considered to be fully uncoupled See notes below Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 Card 3 1 2 3 4 5 6 7 8 Card 4 a 19 78 MAT LS DYNA3D Version 936 MAT Card 5 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density E Young s modulus for compacted honeycomb material PR Poisson s ratio for compacted honeycomb material SIGY Yield stress for fully compacted honeycomb VF Relative volume at which the honeycomb is fully compacted MU u material viscosity coefficient default 05 Recommended BULK Bulk viscosity flag EQ 0 0 bulk viscosity is not used This is recommended EQ 1 0 bulk viscosity is active and 0 This will give results identical to previous versions of LS DYNA3D LCA Load curve ID see DEFINE CURVE for sigma aa versus either relative volume or volumetric strain See notes below LCB Load curve ID see DEFINE CURVE for sigma bb versus either relative volume or volumetric strain Default LCB LCA See notes below LCC Load curve ID see DEFINE CURVE for sigma cc versus either relative volume or volumetric strain Default LCC LCA See notes below LCS Load curve ID see DEFINE CURVE for shear stress versus either relative volume or volumetric strain Default LCSZLCA Each compo
497. word can appear more than once anywhere in the input Also see remarks below Card Format Variable Type VARIABLE DESCRIPTION FILE Filename of the NASTRAN input deck The following table lists supported NASTRAN keywords Version NASTRAN INPUT FILE LS DYNA3D Keyword All N Type NODE Val1 Val2 Val3 NODE All 23456 78 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_OPTIONS LS DYNA3D Version 936 27 5 TRANSLATE TRANSLATE Version NASTRAN INPUT FILE LS DYNA3D 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 supported 2 same keywords LS DYNA3D 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 1 2 3 4 5 6 7 8 9 wispep ebe w
498. wrence Livermore National Laboratory Rept UCID 19156 1981 a Hallquist J O NIKE3D An Implicit Finite Deformation Finite Element Code for Analyzing the Static and Dynamic Response of Three Dimensional Solids University of California Lawrence Livermore National Laboratory Rept UCID 18822 1981 b LS DYNA3D Version 936 30 3 REF REFERENCES Hallquist J O DYNA3D Users Manual Nonlinear Dynamic Analysis of Solids in Three Dimensions University of California Lawrence Livermore National Laboratory Rept UCID 19156 1982 Rev 1 1984 Rev 2 1986 Hallquist J O Theoretical Manual for DYNA3D University of California Lawrence Livermore National Laboratory Rept UCID 19401 March 1983 Hallquist DYNA3D Users Manual Nonlinear Dynamic Analysis of Solids in Three Dimensions University of California Lawrence Livermore National Laboratory Rept UCID 19156 1988 Rev 4 Hallquist J O LS DYNA3D User s Manual Nonlinear Dynamic Analysis of Solids in Three Dimensions Livermore Software Technology Corporation Rept 1007 1990 Hallquist J O D J Benson and G L Goudreau Implementation of a Modified Hughes Liu Shell into a Fully Vectorized Explicit Finite Element Code Proceedings of the International Symposium on Finite Element Methods for Nonlinear Problems University of Trondheim Trondheim Norway 1985 Hallquist J O and D J Benson A Comparison of an Implicit and Explicit
499. xis 4 28 CONSTRAINED LS DYNA3D Version 936 CONSTRAINED CONSTRAINED NODE SET Purpose Define nodal constraint sets for translational motion in global coordinates No rotational coupling See Figure 4 8 Card Format 1 2 3 4 5 6 7 8 VARIABLE DESCRIPTION NSID Nodal set ID see 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 EQ 7 x y and z translational degrees of freedom The masses of the nodes are summed up to total mass of the constrained set It must be noted that the definiton of a nodal rigid body is not possible with this card For nodal rigid bodies the CONSTRAINED NODAL RIGID BODY OPTION has to be used instead LS DYNA3D Version 936 4 29 CONSTRAINED CONSTRAINED CONSTRAINED NODE SET CONSTRAINED NODAL RIGID BO CONSTRAINED SPOTWELD _ Since no rotation is permitted this option should not be used to model rigid body behavior that involves rotations Peters Offset nodes and b are constrained to move together Behavior is like a rigid beam These opt may be used to model spotwelds Figure 4 8 CONSTRAINED NODE SET can lead to nonphysical responses 4 30 CONSTRAINED LS DYNA3D
500. xis by the vector Bx By B 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 xc 2 0 0 0 Ax Ay 1 0 0 and Bx By 0 1 0 Figures 5 3a and 5 3b show the definitions of the geometric contact entities The relationships between the entity coefficients and the Figure 5 3a and 5 3b variables are as follows please note that Px Py Pz is a position vector and that Qx Qy Qz is a direction vector GEOTYP 1 gl Px g4 g2 Py g5 Qy g3 Pz g6 07 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 2 gl Px g4 r g2 g3 Pz 3 gl g4 82 Py 85 g3 Pz g6 Qz g7 r If automatic generation is used a cylinder of length and radius is generated which represents the infinite cylinder LS DYNA3D Version 936 5 23 CONTACT CONTACT 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 GEOTYP 8 gl
501. y 9 BCIZ triangular shell with four thickness integration points 22 C triangular shell with four thickness integration points 11 2 node Hughes Liu beam with four integration points 28 2 node Belytschko Schwer beam 5 2 node simple truss elements 3 8 node solid shell with four through the thickness 33 integration points These timings are very approximate and do not account for the inclusion of sliding interfaces or complex material models Each interface node of the sliding interfaces is roughly equivalent to one half zone cycle in cost Figure L5 illustrates the relative cost of the various shell formulations in LS DYNA3D LS DYNA3D Version 936 1 43 INTRODUCTION INTRODUCTION 30 20 6 o 10 0 BT BTW YASE BWC CHL HL CFHL FHL Element Type Figure 1 5 Relative cost of the four noded shells available in LS DYNA3D 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 YASE shell is the Englemann Whirley shell CHL denotes the Hughes Liu shell HL with one point quadrature and a co rotational formulation FHL is the fully integrated Hughes Liu shell and the CFHL shell is its co rotational version L44 INTRODUCTION LS DYNA3D Version 936 INTRODUCTION UNITS The units in LS DYNA3D must be consistent One way of testing whether a set of units is consistent is to check that 1 force unit 1
502. z 2 19 59 MAT MAT VARIABLE V1 V2 V3 D1 D2 D3 BETA 19 60 MAT DESCRIPTION Components of vector v for AOPT 3 Components of vector d for AOPT 2 Material angle for AOPT 3 may be overridden on the element card This angle is measured with respect to y v x n LS DYNA3D Version 936 MAT MAT COMPOSITE DAMAGE This is Material Type 22 An orthotropic material with optional brittle failure for composites can be defined following the suggestion of Chang and Chang 1982a 1982b Three failure criteria are possible see Theoretical Manual After bulk compression a force can be still transmitted however another bulk modulus has to be given Card Format Card 1 1 2 3 4 5 6 7 8 Card 2 7 Te LE Card 3 LS DYNA3D Version 936 19 61 MAT MAT Card 4 REN Card 5 VARIABLE DESCRIPTION MID Material identification A unique number has to be chosen RO Mass density EA Young s modulus in a direction EB Ep Young s modulus in b direction EC Ec Young s modulus in c direction PRBA Vba Poisson ratio ba PRCA Poisson ratio ca PRCB Vcp Poisson ratio cb GAB Gab Shear modulus ab GBC Gbc Shear modulus bc GCA Gea Shear modulus ca KFAIL Bulk modulus of failed material Necessary for compressive failure 19 62 MAT LS DYNA3D Version 936 VARIABLE AOPT MACF XP YP ZP A1 A2 A3 VLV2 V3 D1 D2 D3 5 XT YT

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