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Theory Manual Version V1a - ftp @ uni

1. Computing effort average Size of element stiffness matrix 36x36 Shell No 23 FR curvilinear isoparametric Serendipity shell element Shape functions quadratic isoparametric transformation all nodes in one plane good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort high Size of element stiffness matrix 48x48 14 Zod Aurora 56 Theory Manual Shell No 24 FR curvilinear isoparametric Serendipity shell element Shape functions quadratic isoparametric transformation all nodes in one plane good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort average Size of element stiffness matrix 36x36 SPATIAL PROBLEMS Truss No 4 Br Linear function Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Minimal Size of element stiffness matrix 6 x 6 15 Us Theorie Manual Beam No 2 Br Linear function for tensile stress cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Low Size of element stiffness matrix 12 x 12 Z U parallel to x y plane X Uy Hexahedron No 1 tr
2. Linear shape functions Quality of displacements average Stresses in the Gauss points useable Stresses in corner nodes inaccurate Computing effort very high a Size of element stiffness matrix 24 x 24 Hexahedron No 10 y Quadratic Isoparametric Serendipity element Quality of displacements very good Stresses in the Gauss points very good Stresses in corner nodes good Computing effort extremely high Size of element stiffness matrix 60 x 60 1 16 Mah Aurora 126 Theory Manual Tetrahedron No 17 4 Linear shape functions Quality of displacements bad Stresses in the Gauss points inaccurate Stresses in corner nodes very inaccurate Computing effort medium Size of element stiffness matrix 12 x 12 Tetrahedron No 16 gt Quadratic Isoparametric Serendipity element Quality of displacements very good Stresses in the Gauss points very good Stresses in corner nodes good Computing effort very high Size of element stiffness matrix 30 x 30 17 LIB oo Theorie Manual 2 THE Z88 COMPUTING UNITS 2 1 Overview Z88 always exclusively works at the tasks required at the moment Under the new user inter face the established Z88 programs are accessed Z88 is no gigantic monolithic program but consists of several separate running modules according to the UNIX philosophy Small Is Beautiful They are loaded into the main memory according to your requirements
3. Torus elements No 8 can be generated by the mesh generator Z88N from super elements torus elements No 12 Thus the torus element No 12 is well suited as super element But torus ele ments No 12 cannot be generated by the mesh generator Z88N from super elements torus ele ments No 12 Input CAD see chapter 2 7 2 1 5 6 2 7 8 3 9 10 4 11 12 1 7881 TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt IOFLAG 1 if edge loads for this element are filed in ZSSI5 TXT gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 12 gt 12 nodes per element gt Cross section parameter OPARA is 0 or any value no influence gt Integration order per each mat info line 3 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z88I1 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG any has no influence gt Reduced stress flag ISFLAG 115 LIB or Theorie Manual 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815
4. Damage For Fiber Reinforced Composites Porous Elastic rT F F F F hy Damage For Elastomers Wiewoe Gee Deformation Plasticity Damping Expansion Theory Manual Mesh Controls Element Shape Technique Algorithm E C Medial axis O Free 4 Minimize the mesh transition haz structured E Advancing front ie Sweep o Bottom up f Multiple Use mapped meshing where appropriate Redefine Sweep Path Brittle Cracking Ok Defaults Cancel Figure 24 Generating a new linear elastic material and allocation of the appropriate element type in ABAQUS 6 8 4 Note Extended settings of the mesh control and element selection are not adopted since there are no corresponding equivalents in Z88 Aurora Thus in case you have chosen hybrid formu lation or an element for acoustic analysis this will be transformed into a pure Z88 type when being imported into Z88 83 Us Theorie Manual Applying boundary conditions and loads Loads are best defined via the option Displacement Rotation and by defining the correspond Edit Material x Name material 1 Description Material Behaviors Delete General Mechanical Thermal Other Elasticity b Plasticity F Hyperelastic Damage For Ductile Metals b Hyperfoam Damage For Traction Separation Laws k Hypoelastic Damage For Fiber Reinforced Composites I Porous Elastic Damage For Elastomers b
5. 89 7 gt Thus 156 2 45 3 89 7 Example 2 The node no 68 is supposed to have 6 degrees of freedom a Beam No 2 is at tached and cylindrical coordinates R 100 PHI 0 7854 corresponds to 45 Z 56 87 gt Thus 68 6 100 0 7854 56 87 26 Hah Aurora 56 Theory Manual L E o Oooo 3 input group Starting after last node contains coincidence 1 e the allocation of the element type and the corresponding nodes of every element Edit two lines for every finite element The element numbers like the node numbers must be entered strictly ascending 1 line Ist number Element number Long 2nd number Element type 1 to 24 Long 2 line Depending on element type Ist number 1 node number for coincidence 2nd number 2 node number for coincidence th th aes 20 number 20 node number for coincidence Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long Example An Isoparametric Serendipity Plane Stress Element No 7 has element number 23 The coincidence has the global nodes 14 8 17 20 38 51 55 34 locally these are the nodes 1 2 3 4 5 6 7 8 gt Thus resulting in two lines 23 7 14 8 17 20 38 51 55 34 an input group Starting after last element contains Material information one line for each material informa tion Write all numbers into a line separate at least by one blank respectively Ist number This material information
6. Z8813 TXT gt INTORD any has no influence gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no reduced stress calculation 1 von Mises stresses plotted in the centre of gravity 2 principal or Rankine stresses plotted in the centre of gravity 3 Tresca stresses plotted in the centre of gravity Results Displacements in R and Z X and Y Stresses The stress are internally computed in the corner nodes but plotted in the centre of gravity It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises stresses Nodal forces for each element and each node 105 LIB Theorie Manual 5 7 PLANE STRESS ELEMENT NO 7 WITH 8 NODES This is a curvilinear Serendipity plane stress element with square shape functions The trans formation is isoparametric The integration 1s carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z8811 TXT in the material information lines The order 3 is mostly sufficient This element calculates both dis placements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calcu lated in the Gauss points substantially more
7. formation is contained in the file Z88MANAGE TXT When importing existing Z88 files the data contained in Z8813 TXT are transferred automatically into Z8S8MANAGE TXT Subse 36 Zod Aurora 126 Theory Manual quent changes to Z8813 TXT however remain ineffective Immediately before the calcula tion Z88 Aurora generates a new Z8813 TXT which contains all the new parameters Mind the following format Long 4 bytes or 8 bytes integer number File only consists of only one line 1st value For isoparametric elements No 1 7 8 10 11 12 14 15 16 17 18 19 20 Value of the integration order INTORD Long Valid 1s 0 Calculation of stresses into the corner nodes reduced stress calculation not possible For isoparametric elements No 1 7 8 10 11 12 19 20 23 1 2 3 or 4 1 e NXN Calculation of stresses into the Gauss points Reduced stress calculation is possible A good value is 3 3x3 Gauss points For element type No 1 and No 20 a value of 2 could be fine For type No 19 a value of 4 4x4 Gauss points is recommended For isoparametric elements No 14 15 18 24 3 7 or 13 i e N Calculation of stresses into the Gauss points Reduced stress calculation is possible A good value is 7 7 Gauss points For type No 18 a value of 3 1 e 3 Gauss points could be fine For isoparametric elements No 16 17 1 4 or 5 1 e N Calculation of stresses into the Gauss points Reduced stress cal
8. gt Cross section parameter OPARA is the element thickness gt Second moment of inertia RIYY is the surface load gt Integration order INTORD per each mat info line 4 is usually good 78813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and normally not used here because it is much more convenient to enter the pressure data for the plate elements into Z8811 TXT in the section material information However the possibility for entering the pressure loads by the surface and pressure loads file Z88I5 TXT too is implemented for universal use of this file Then set IQFLAG to 1 and proceed as follows gt Element number with pressure load gt Pressure positive if pointing towards the edge Results Displacements in Z i e w and rotations 0 around X axis and 0 around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their
9. 109 LIB Theorie Manual 59 TRUSS NO 9 IN PLANER The truss element No 9 can take any location in the X Y plane It is the simplest element in Z88 and is calculated extremely fast The truss elements match Hooke s law exactly Y 2 1 Input CAD see chapter 2 7 2 Line from node I to node 2 Z8811 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 9 gt 2 nodes per element gt Cross section parameter OPARA is the cross sectional area of the truss Z8813 TXT Trusses No 9 have no influence However Z8813 TXT must exist with any content Results Displacements in X and Y Stresses Normal stresses Nodal forces in X and Y for each element and each node 110 Z66 Aurora Yos Theory Manual 5 10 HEXAHEDRON NO 10 WITH 20 NODES This 1s a curvilinear Serendipity volume element with square shape functions The transfor mation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre Thus the integration order can be selected in Z88I1 TXT in the material information lines The order 3 is good The quality of the displacement and stress calculations are far better than the results of the hexahedron element No 1 Hexahedron No 1 also applies well for thick plate elements if the plate s thickness is not too small compared to the other dimensions The element causes an enormous computing load and needs an extr
10. 64 bit Windows version of Z88 e The so called sparse matrix iteration solver It solves the system of equations by the method of conjugate gradients featuring SOR preconditioning or preconditioning by an incomplete Cholesky decomposition depending on your choice This solver needs a minimum of storage It is your choice for large structures with more than 150 000 200 000 DOF FE structures with 5 million DOF are no problem for it if you use a 64 bit operation system Windows or Mac OS X along with the 64 bit version of Z88 and about 6 GByte of memory This very stable and approved solver works always thus you may use it as your standard solver Note The following explanations for the manual launch of the solver are only meant for a deeper understanding if necessary Z88 Aurora takes care of everything for you The solver Z88R runs in console mode and requires two control flags z88r mode solver mode means t Test mode Z88R determines the required memory and enters these settings into the memory definition file Z88R DYN c Computing mode Z88R DYN is imported Run the solver in test mode first and then a second time in computing mode using the same setting of the second parameter solver solver means choly Launch of the simple Cholesky solver without fill in with Jennings storage parao Launch of the direct sparse matrix solver with fill in and solver PARDISO siccg Launch of the iteration solver conjugated
11. Cross section parameter OPARA is insignificant gt Integration order for each mat info line 3 7 and 13 are possible 7 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 3 7 13 Calculation of the stresses in the Gauss points e g 7 7 Gauss points gt KFLAG has no influence gt Reduced stress flag ISFLAG 134 766 Aurora 56 Theory Manual 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file 1s optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 22 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view Y r4 Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 135 LIB Theorie Manual 5 23 SHELL NO 23 WITH 8 NODES FR This is a
12. DXF_ Exchange file for CAD programs and for CAD converter Z88X_ STP import of geometry for internal mesh generator STL import of geometry for internal mesh generator __ Z88NLTXT input file for mesh generator Z88N_ o ee y X edit just in exceptional cases may provoke program abortion by wrong input p IZR Dimensions 1 e measurement units are not used explicitly You can work in optional meas urement systems e g in the Metric or Imperial measurement system Use inches Newton s pounds tons millimetres meters and yards whatever you prefer But make sure to keep the one chosen measurement units throughout all computations of this structure Example You want to work with mm and N so Young s modulus must be used in N mm Why work with files Is that not old fashioned and does interactive working not do a better job In Z88 Aurora you have both possibilities 22 Zod Aurora 126 Theory Manual Any kind of preprocessing and postprocessing is possible without restrictions You can generate the input files by small self written pre programs such a pre program is the mesh generator Z88N or leave the job of processing the output data to other programs You can quite easily load Z88 output files into EXCEL and analyse them there Or you use Z88 Aurora and manual adjust the input in the text editor later 1f necessary because only few boundary conditions have changed or you want to use a differen
13. Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 99 LIB or Theorie Manual 52 BEAM NO 2 WITH 2 NODES IN SPACE E Beam element with any symmetric profile no slanting bend with the restriction that the local y y axis must be parallel to the global X Y coordinate system The profile values are provided in Z8811 TXT Thus you can use any symmetric profile in contrast to other FEA programs which sometimes incorporate a variety of different special beam and profile subroutines with out matching all symmetric profiles as necessary The element matches exactly Bernoulli s bend theory and Hooke s law It uses no approximate solution as for the continuum elements parallel to x y plane AU a Input CAD see chapter 2 7 2 Line from node I to node 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt Set beam flag IBFLAG to 1 gt 6 degrees of freedom in a node Attention DOF5 not right hand rule see below gt Element type is 2 gt 2 nodes per element At the material information lines gt Integration order INTORD is arbitrary 1 4 has no influence gt Cross sectional area QPARA gt Second moment of inertia RIYY bending around y y axis gt Max distance EYY from neutral axis y y gt Second momen
14. Integration order for each mat info line 3 7 and 13 are possible 7 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 138 Zod Aurora 56 Theory Manual 0 Calculation of the stresses in the corner nodes 3 7 13 Calculation of the stresses in the Gauss points e g 7 7 Gauss points gt KFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file 1s optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 24 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view EN Results Displacements in X Y and Z and Rotations inclination around X and Y axis 0 u Oy Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The stresses SIGXX SIGYY and TAUXY as well as optionally von Mises or principal or Tresca stresses are output Nodal forces first for each element then for each node 1
15. Number of constraints MAXRBD fisooo 0 t OO CCCS Number of pressure loads MAXPR ETT Material Number of materials MAXMAT 1000 Number of material laws MAXNEG 20 Pairs of temperature MAXXEPTHE 100 Pairs of matenal nl MAXXEPMAT 100 Matenal model nl MAXMAPAR 100 eo Figure 9 Memory settings in the options menu In the 32 bit versions Z88 Aurora uses e Floating point numbers with doubles 8 Bytes and e Integers and pointers with longs 4 Bytes In the 64 bit versions Z88 uses e Floating point numbers with doubles 8 Bytes and e Integers and pointers with longs 8 Bytes Figure 10 shows an example for a file Z88 DYN with the mentioned keywords DYNAMIC START Z88 new version 14 0 Z88 new Version 14 0 LANGUAGE SPRACHE GERMAN Common entries for gemeinsame Daten fuer all modules alle Module COMMON START MAXKOL 3000000 MAXK 700000 MAXE 300000 MAXNEG 100 MAXGP 2000000 MAXOTE 5000000 MAXSTRUGEOELE 50 MAXLASTF 300 MAXSTLK 50000 MAXMAT 1000 49 Theorie Manual MAXXEPTHE MAXXEPMAT MAXMAPAR MAXMMREG MAXSTAT MAXF REQ MAXNF G MAXRBD MAXPR MAXPRT COMMON END DYNAMIC END 100 10000 100 10000 50 20 100000 100000 100 1 Figure 10 Example of the definition file Z88 DYN The file must start with the keyword DYNAMIC START and end with the keyword DY NAMIC END By entering GERMAN German is selected as language for English sele
16. according to the definition The geometry however can mostly be used well also in FE programs if a few points are taken into account e Any STEP converter of a CAD program is only as good as the applied graphic kernel Thus if the CAD display contains mistakes these mistakes are ex ported along with the data and might impede the processing These mistakes are partially caused by the kernel itself partially by the export of cluttered models e Inthe CAD system apply a modelling tolerance as high as possible geometri cal tolerance e g lt 0 01 if you have the possibility to repeatedly specify a tol erance during export select a higher one than the modelling tolerance e g 0 01 e Make sure that you use AP203 or AP214 during export e Should problems during the import arise consider simplifying your model be fore exporting it Often small roundings or chamfers are the cause for very small edges and surfaces which impede the processing If they are not manda tory for the FE simulation they can be eliminated and therefore not exported Which CAD systems can cooperate with Z88X Any CAD systems which can export 1 e write STEP files However we cannot guarantee any SUCCESS 59 Hah Aurora Theorie Manual Which elements are supported by the converter Z88 Aurora first generates an STL file from the imported STEP files for visualization This can be transferred into structures from elements No 16 or No 17 linear or q
17. execute their tasks and release the main memory again In this way Z88 s achieves its enormous speed and faultlessness beating many other FE programs The Z88 modules communicate by files cf Chapter 3 2 2 Short Description of the Modules I THE PRE AND POSTPROCESSOR 1 In addition to the established Z88 modules Z88 Aurora possesses a graphic user interface All input which in Z88 V13 was made via the input files Z8811 5 TXT is now directly made in Z88 Aurora But of course existing input files from Z88 V13 can be imported into Z88 Aurora any time For the plotting of results the approved Z880 was extended and adjusted Further more for the further use of the results the files Z8801 8 TXT can be displayed and printed II THE SOLVER EE The solver is the heart of any FEA system It reads the general structure data Z8811 TXT and the boundary conditions Z8812 TXT and if necessary the file for surface and pressure loads Z8815 TXT Basically the Z88 input files can be created by CAD converter Z88X by 3D converter Z88G by mesh generator Z88N by editor or word processor system or by a mixed procedure e g by CAD and editor The solver generates prepared structure data Z8800 TXT and processed boundary conditions Z8801 TXT calculates the element stiffness matrices compiles the total stiffness matrix scales the system of equations solves the huge system of equations and stores the displacements in Z8802 TXT Therefore the main ta
18. sparse direct and you have two double core CPUs installed in your computer gt Thus MAXITStandard value without significance EPS Standard value without significance RALPHA Standard value without significance ROMEGA Standard value without significance ICORE4 46 Plate Aurora vos Theory Manual Example 4 You want to use the Cholesky solver gt Thus The control values MAXIT EPS RALPHA ROMEGA and ICORE can be arbitrary and are without significance STRESS See remarks on Z8813 TXT In the menu Solver under Solver options the parameters of the single solvers can be ed ited For further information on the use of the solver menu see User Manual For further in formation on the Cuthill McKee program Z88H see chapter 4 2 4 gp Solver options General 2 Warning Repeated node sorts may produce worse numbering a Number of CPUs to be used during calculation iterative solvers Max iterations 10000 Important for huge FE structures Residuum 1e 007 Sum of error to analytic result alpha SIC 0 0001 Shift factor for partial Cholesky decomposition recommended 0 0001 0 000001 omega SOR 1 1 Factor for successive overrelaxation SOR recommended 0 8 1 2 Direct solver Pardiso C OOC memory MB 1000 Memory used in out of core mode Swap directory amp Main C v Directory for swap file used in out of core mode X Cancel Figure 7 Solver options menu for the control of the s
19. surface load is applied normally to the edge with 100 N mm and the other surface load is ap plied tangentially and positive in local r direction with 300 N mm defined by the two corner nodes Thus FLA 3 97 100 300 5 13 51 gt Hexahedron No 1 Element number with surface and pressure load Pressure positive if pointing towards the surface Tangential shear positive in local r direction Tangential shear positive in local s direction 4 nodes of the loaded surface Example The hexahedron 356 is the 34th element with surface loads The load should be applied onto the surface defined by the corner nodes 51 34 99 and 12 The first surface load is pressure with 100 N mm The second surface load is applied tangentially and positive in local r direction with 200 N mm The third surface load is applied tangentially and positive in local s direction with 300 N mm Thus FLA 34 356 100 200 300 51 34 99 12 gt Hexahedron No 10 Shells No 21 and No 22 Element number with surface and pressure load Pressure positive if pointing towards the surface Tangential shear positive in local r direction Tangential shear positive in local s direction S nodes of the loaded surface Plate elements No 18 19 and 20 Shells No 23 and 24 Element number with pressure load Pressure positive if pointing towards the surface It is easier to enter the pressure loads for plate elements directly into Z8811 TXT than via Z8815 TXT Separate each i
20. 1 line Ist number Element number Long 2nd number Super element type 1 7 8 10 11 12 20 21 Long 2nd line Depending on element type Ist number Ist node number for coincidence 2nd number 2nd node number for coincidence 20 number 20th node number for coincidence Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long Example An Isoparametric Serendipity Plane Stress Element No 7 has element number 23 The coincidence has the global nodes 14 8 17 20 38 51 55 34 locally these are the nodes 1 2 3 4 5 6 7 8 see chapter 4 7 gt Thus resulting in two lines 23 7 14 8 17 20 38 51 55 34 30 Z66 Aurora 126 Theory Manual E _ _ __ gt _ _ _ AAA a 4 input group Starting after last super element contains material information one line for each material in formation Write all numbers into a line separate at least by one blank respectively Ist number This material information line starts with super element no inclusively Long 2nd number This material information line ends with super element no inclusively Long 3rd number Young s Modulus Double 4th number Poisson s Ratio Double 5th number Integration order 1 2 3 or 4 Long 6th number Cross section value OPARA Double And if plates are defined and IOFLAG 0 in addition 7th number Surface load No beam data here in contrast to Z88I1 TXT because beams
21. 22 23 and 24 The plate elements No 18 19 and 20 may read the pressure loads via Z88I5 TXT then set IPFLAG 1 and IQFLAG 1 but it is easier to define the pressure loads directly with the material entries of the file Z8811 TXT then set IPFLAG 1 and IQFLAG 0 Example 1 A three dimensional structure of tetrahedrons No 16 features 100 elements 180 nodes 540 DOF I material information line no change of coordinate system no beams no plates use the surface and pressure loads file ZSSI5 TXT gt Thus 3 180 100 540 10001 0 Example 2 A plate structure of elements No 18 features 1000 elements 2000 nodes 3000 DOF 3 material information lines no change of coordinate system no beams use the surface and pressure loads file Z8815 TXT gt Thus 2 2000 1000 3000 300110 IHFLAG The shell flag is 1 when using shell elements 2 input group Starting with line 2 contains coordinates of nodes one line per node node numbers strictly ascending 1 number node number Long 2 number Number of the degrees of freedom for this node Long 3 number X coordinate or if KFLAG is 1 R coordinate Double 4 number Y coordinate or if KFLAG is 1 PHI coordinate Double 5 number Z coordinate or if KFLAG is 1 Z coordinate Double The Z coordinate can be dropped at 2 dimensionalen structures Enter angles PHI in radian Example 1 The node no 156 has 2 degrees of freedom and the coordinates X 45 3 and Y
22. 36 3 1 5 PARAMETER FILE Z88I4 TXT oo cccccccccsssssssssseeeeeeeeeceeeeeeessesessssseeeeeeeeeeeeeeeeeeeeeeeas 38 3 1 6 SURFACE PRESSURE LOADS FILE Z88I5 TXT cooooccccccccccnnnnnnnonnnononnnnnnnnnnccnnnnnnnnnaononnnnnnnos 38 317 MATERIAL FILE ZSS MA LEXT aida dt 43 3 1 8 ELEMENT PARAMETER FILE Z88ELP TXT ccc cccccccccccceeesseessessnneeeeeeeeeeeeeeeeeeeeeeeas 44 3 1 9 SOLVER DEFINITION FILE Z88MANAGE TXT oo cccccccccccecsesssssnsseeeeeeeeeceeeeeeeeeeeeeas 44 3 1 10 OUTPUT FILES 28800 TXT to ZSSOS8 TXT aia 47 3 1 11 DERINTTION TICE ZDNet E 47 3 1 12 A DEFINITION FILE Z88ENVIRO DYN occcccccnnnnnnonnononnnonnnnnnnncnccnnnnnnnnnnnnononnnnnnnnncncnnns 52 4 THE Z9 MODULE Serra cas 55 4 1 Interfaces and file converters for CAD and FE programs ccccccccseeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeees 55 4 1 1 Importing files from previous Z88 Versions up to VlB oooooooocononononanonnononononononnnnnnnonononononnnos 58 4 1 2 The STEP Import into Z88 Aurora Z88geokon Step ooooooonnnonnoooononoooooonnnnnnonnnnnnnnnnnnononnnnoos 59 4 13 the SUL converter 88gcocon S TL aitor coto dns a 61 4 14 The DXF converter in Aurora Z88X cooooooocoooooccnnnnnnnnnnnnnnnnnonononononnnnnnnnnnnnnnnnnnnnn cnn ono nn nn nn nn nn nnnnnnss 62 Als ARONECADESY IV OB eta 64 4 1 6 FROM Z88 TO CAD SYSTEM oocccccnnnnnonononnnnnnnnnnnnncncnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn ns 65 Alr A E E E E A E E E 65 BN SS
23. E ae TOER iE 77 41 9 THEANSYS COn e oz dls seca 79 4 1 10 The ABAQUS converters Z88ainp and ZESACXD cocccccccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnos 80 AD Thelinear solver LoS aia tdt 85 dal A EE OER ei 89 4 2 2 Some NOTES OM Stress CAC Ul AU ON 3 5 5 cpccsce hp cahsecdeadatwnasaadsecansastasandseadualatenauandsedoussastdbeacdseeduotens 89 4 2 3 some notes on nodal force calculation ooonoonnnononooononooononononnnnnnnnnnnnnnnnnnnnnnnonnnnnnn non nnonnnnnnnos 89 4 2 4 The CUTHILL McKEE PROGRAMM Z88H occoccccccnnnnononnnonnnnnnnnnnnnnnccnononnnnnnnnnnnnnnnnnnnnnnncncnnns 89 4 3 The mapped mesher Si mesi CUCL ALON Z8 SIN eii 91 5 4 4 5 1 5 2 5 3 5 4 gt 5 6 Sl 5 8 5 9 5 10 5 11 5 12 5 13 5 14 5 15 5 16 5 17 5 18 5 19 5 20 5 21 J22 5 23 5 24 L8G Theorie Manual 4 3 1 CHD ORE A 91 TEE POSTPROCESS OR coincida 94 DESCRIPTION OF THE FINITE ELEMENTS ccccccec cece ccccccscccecccscccsccceccccccescccssccesccesccnesececcceaccs 98 HEXAHEDRON NO 1 WITH 8 NODES Ne BEAM NO 2 WITH 2 NODES IN SPACE Bre PAO EA PAE AE NE A EAEE PENA PE EAE IEEE E PA E A 100 ES PLANE STRESS TRIANGLE NO 3 WITH 6 NODES LF 00 c ccc ecceccsccsccceccecescesceseecs 102 TRUSS NO 4 IN SPACE A EIEE E EE EEA AAA ENEE ENNE A AAAA AEN 103 CAM ELEMENT NO 5 WITH 2 NODES ot A ss eedue coucuoseetedea E AE 104 TORUS NO 6 WITH 3 NODES Ds EEPE A AE AE AI EAEE TE E 105 Es PLANE STRESS ELEMENT NO 7 WITH 8 NOD
24. Element number gt Pressure positive if pointing towards the surface gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence E Results Displacements in X Y and Z and Rotations inclinations around X and Y axis 0 u 0 Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The stresses SIGXX SIGYY and TAUXY as well as optionally von Mises or principal or Tresca stresses are output Nodal forces first for each element then for each node 137 LIB or Theorie Manual 5 24 SHELL NO 24 WITH 6 NODES FR This is a curvilinear Serendipity shell element with square shape functions The transforma tion is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre All nodes have to be on a common surface which can be placed arbitrarily in a space which is very useful for the data exchange with 3D CAD systems The integra tion order can be selected in Z8811 TXT in the material information lines The order 7 1 e 7 Gauss Points is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calcul
25. SEH 13 952 006 4 SEE HO el REP AE H 5 ES 5 BSE He HI REA 15 EA E HE 205 HO Deplicements X Dep lacinarts Y Gsplacererts I Magriftiude of displacermenrttde Dress at corner podes Sirens per element ohet dicto Cp nor roo papa aika Beam REA 1 1 General overview of the FE program Z88 Aurora THE Z88 PHILOSOPHY IS ALSO VALID FOR Z88 AURORA Fast and compact Developed for PC no ported mainframe system full 64 BIT support for Windows and Mac native Windows and Mac OS X programs no emulations Windows and Mac OS X versions use the same computing kernels full data exchange from and to CAD systems DXF and new STP STL FE structure import COS NAS and new BDF ANS INP and new FE export INP context sensitive online help and video tutorials simplest installation with Microsoft Installer MSI Z88 Aurora is fully compatible with Z88 V13 Existing Z88 V13 files can simply be imported LIB Theorie Manual Note Always compare FE calculations with analytical rough calculations results of experi ments plausibility considerations and other tests without exception Keep in mind that sign definitions of Z88 and also other FEA programs differ from the usual definitions of the analytical technical mechanics from time to time Z88 Aurora is a powerful complex computer program which is still in the developm
26. SIGXY 1 SIGXY2 Bending stress in X Y plane for node 1 and node 2 SIGXZ1 SIGXZ2 Bending stress in X Z plane for node and node 2 Nodal forces in X Y and Z and nodal moments around X Y and Z for each element and each node Algebraic sign X Y plane X Z plane 104 Mah Aurora 126 Theory Manual 56 TORUS NO 6 WITH 3 NODES This element is implemented only for historical reasons and possible data exchange to other FEA systems Much better Torus No 8 or Torus No 12 or No 15 No entries into the surface and pressure loads file Z88I5 TXT This is a simple triangular torus element with linear shape functions for rotational symmetric structures The displacement results for this very simple element are quite useable but the stress calculation results are inaccurate The stresses are calculated in the corner nodes inter nally and then distributed as average value in the centre of gravity However the use of the torus elements No 8 or No 12 or No 15 is highly recommended especially for accurate stress calculations Z Y 2 R X Input CAD see chapter 2 7 2 1 2 3 1 Z8811 TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 6 gt 3 nodes per element gt Cross section parameter OPARA is 0 or any value no influence
27. System Properties gt Advanced gt Environment Variable you do not have this kind of variable NUM THREADS OMP SET NUM THREADS This might clash with the settings in Z38MANAGE TXT 88 Z66 Aurora 126 Theory Manual 4 2 1 WHICH SOLVER TO TAKE Roughly spoken Use the simple and reliable Cholesky solver Z88F for small structures The sparse matrix iteration solver Z88R siccg or sorcg always works even for very large struc tures under 32 bit operating systems For medium sized structures the direct sparse matrix solver with fill in Z88R parao is very suitable because of its tremendous speed Table 6 Overview of the integrated solvers and their efficiency Solver Type Number of DOF Memory Speed Multi Notes needs CPU running Z88H pd ed up to 30 000 medium medium no first is recommended useful with direct Solver with up to 150 000 several CPUs and Fill In with 32 Bit PCs vry nign very high yea very much memory Conjugated No limits tested oe a very stable and eE o soler wi more than 12 apsolute medium no felable ser SOrcg conditioning normal PC structures 4 2 2 SOME NOTES ON STRESS CALCULATION The results are presented in the file Z8803 TXT The stress calculation is controlled via the file Z88MANAGE TXT see chapter 3 It defines among other things e Calculation of the stresses at the Gauss points or at the corner nodes e Additional calculation of radial and tangential stresses for elements N
28. are forbidden in the mesh gen erator Explanation cross section value QPARA QPARA is element type dependent e g for hexahedrons 0 for trusses the cross sectional area and for plane stress elements the thickness Here are the mesh generator suitable ele ments Element No 1 Isoparametric Hexahedrons 8 nodes Element No 7 Isoparametric Serendipity Plane Stress Element 8 nodes Element No 8 Isoparametric Serendipity Torus 8 nodes Element No 10 Isoparametric Serendipity Hexahedron 20 nodes Element No 11 Isoparametric Serendipity Plane Stress Element 12 nodes Element No 12 Isoparametric Serendipity Torus 12 nodes Element No 20 Isoparametric Serendipity Plate 8 nodes Element No 21 Isoparametric Serendipity Shell 16 nodes Example The structure has 34 super elements No 7 The thicknesses are supposed to vary Elements I to 11 thickness 10 mm elements 12 to 28 15 mm and elements 29 to 34 now 18 mm Material steel Integration order shall be 2 gt Thus three material information lines I I 11 206000 0 3 2 10 2 12 28 206000 0 3 2 15 329 34 206000 0 3 2 18 amp 5 input group Starting after last material information line contains the descriptive details for the mesh gen eration process 2 lines for every super element Ist line Ist number Super element no Long 2nd number Finite element type types I 7 8 10 19 20 to be generated Long 2nd line Ist number Number of finite elements in local x dir
29. element are filed in Z8815 TXT gt 3 degrees of freedom for each node gt Element type is 1 gt 8 nodes per element gt Cross section parameter OPARA is 0 or any other value has no influence gt Integration order INTORD for each mat info line 2 is usually good Z8813 TXT gt Integration order INTORD for stress calculation Can be different from INTORD in Z8811 TXT 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points gt any KFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 98 Zod Aurora 56 Theory Manual 1 von Mises stresses in the Gauss points INTORD not 0 2 principal or Rankine stresses in the Gauss points INTORD not 0 3 Tresca stresses in the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces surface and pressure loads applied onto element no 1 gt Element number with surface and pressure load gt Pressure positive if pointing towards the surface gt Tangential shear positive in local r direction gt Tangential shear positive in local s direction gt 4 corner nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 2 3 4 may differ from the local nodes 1 2 3 4 used for the coincidence Results
30. gradients with SIC preconditioning sorcg Launch of the iteration solver conjugated gradients with SOR preconditioning Input files for both modes 85 LIB Theorie Manual e Z88I1 TXT general structure data Z8812 TXT boundary conditions Z88I3 TXT control values for stress calculation Z88I5 TXT surface and pressure loads if necessary Z88MAT TXT and a material file in CSV format if the new Z88 Aurora format is supposed to be used Otherwise the material data imported from the file Z8811 TXT as it was the case with Z88 V13 NOTE These files are described more precisely in chapter 3 Output files in computing mode Z8800 TXT prepared structure data for documentation Z8801 TXT prepared boundary conditions for documentation Z8802 TXT Displacements Z8803 TXT Stresses Z8804 TXT Nodal forces Under Postprocessor gt Outputfiles you can access the single output files of the calcula tion in order to get the exact numerical values there for further information see Z88 Aurora Theory Manual e Z88O0 TXT prepared input data Z88O1 TXT prepared boundary conditions Z8802 TXT calculated displacements Z88O03 TXT calculated stresses Z8804 TXT calculated nodal forces Definition files for the solver e Z88MANAGE TXT in this case especially please take care to set the parameters NEG number of material laws and IQFLAG surface load flag which 1s done on the first line of the file Z8811 TXT in case of Z88 V13 NO
31. in node 99 and which other node reads 21 4th step Define the Layer Z88EIO and make it the active layer Write the element informa tion with the TEXT function anywhere of course it looks nicer with the element info s placed in middle of the respective finite element or super element The order of the work se quence is up to you You can describe element 1 first step to the attaching element 17 and then proceed with element 8 However your element choice and description must make sense for an FE analysis The following information has to be written For all finite element types from 1 to 20 not 16 and 17 FE Element number Element type Write into one line separate each item by at least one blank Example An Isoparametric Serendipity Plane Stress Element No 7 is supposed to get the element no 23 Write e g into the middle of the element with the TEXT function FE 23 7 For super elements 2 dimensional No 7 8 11 12 and 20 SE Element number Super element type Type of the finite elements to be produced by meshing Subdivision in local x direction Type of subdivision in local x direction Subdivision in local y direction Type of subdivision in local y direction Write into one line separate each item by at least one blank Example Subdivide an isoparametric Serendipity Plane Stress Element with 12 nodes Ele ment type 11 used as super element into finite elements of type 7 1 e isoparametric Seren dipity Plane Stres
32. layer dimensions on a third layer invisible lines and centre lines on a fourth layer and so on This enables you to remove all unnecessary information in the next step 2nd step Plan your mesh subdivision that means suitable finite element types and their dis tribution Subdivide the FE structure or the super structure into elements by lines insert all points which are not yet existing for example intersection points or end points of lines are usable Any order and layer However it is recommended not to use the Z88 layers like Z88NET Z88GEN Z88PKT Z88KNR Z88EIO and Z88RBD Better define any new layer 65 LIB Theorie Manual for this or use already available layers from step 1 3rd step Define the Z88 Layer Z88KNR and make it the active layer Catch or trap every FE node which were already defined in the 1st step by your construction or have been completed in the 2nd step and number them Write to every node P blank node number e g P 33 with the TEXT function of the CAD program Be very careful to snap exactly the node and attach the number exactly to the node s location Take your time With the snap modes of AutoCAD intersection point end point point etc this works well Choose any order of the work se quence as you like you can well number the node 1 P then the node 99 P 99 and then node 21 P21 However the numbering of the nodes must make sense and must be meaning ful for an FE analysis You define which node
33. line starts with element no inclusively Long 2nd number This material information line ends with element no inclusively Long 3rd number Young s Modulus Double 4th number Poisson s Ratio Double 5th number Integration order 0 1 2 3 4 5 7 or 13 Long 6th number Cross section value OPARA Double And if beams but not plates are defined in addition 7th number Second moment of inertia yy bending around yy axis Double Sth number Max distance from neutral axis yy Double 9th number Second moment of inertia zz bending around zz axis Double 10th number Max distance from neutral axis zz Double 11th number Second moment of area torsion Double 12th number Second modulus torsion Double And if plates but not beams are defined and IOFLAG 0 in addition 7th number area load Explanation cross section value QPARA QPARA is element type dependent e g for hexahedrons QPARA is 0 for trusses QPARA is the cross sectional area and for plane stress elements QPARA is the thickness See list of fi nite elements chapter 5 2 LIB or Theorie Manual Example The structure has 34 finite elements No 7 The thicknesses is supposed to vary Elements I to 11 thickness 10 mm elements 12 to 28 15 mm and elements 29 to 34 now 18 mm Material steel Integration order is supposed to be 2 gt Thus three material information lines I I 11 206000 0 3 2 10 2 12 28 206000 0 3 2 15 3 29
34. locations The following results will be presented plate bending moments M and M unit force x length length plate torsion moments M M unit force x length length the shear forces Q and Q unit force length the true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 129 LIB or Theorie Manual 5 20 PLATE NO 20 WITH 8 NODES amp 4 This is a curvilinear Serendipity Reissner Mindlin plate element with square shape functions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z8811 TXT in the material information lines The order 2 2 x 2 points is mostly sufficient reduced integration This element calculates both displacements and stresses quite good The integration order can be chosen again for the stress calculation The stresses are calcu lated in the corner nodes good for an overview or calculated in the Gauss points substan tially more exactly Area loads are defined in the appropriate material lines file Z8811 TXT instead of Second moment of inertia RIY Y For this element you need to set the plate flag IP FLAG to 1 Attention In contrary to the usual rules of the classic mechanics Z88 defines Ox the rotation around the X axis and 0 the rotat
35. mode Swap directory amp Main C v Directory for swap file used in out of core mode Y cancel Figure 25 Extended options of the solver menu Explanations to the direct sparse matrix solver with fill in This solver does direct matrix decomposition but in contrary to the simple Cholesky solver this solver operates with fill in Fill in means allocating dynamic memory for the new matrix elements created by the decomposition process Thus the memory needs cannot be calculated before running the solver If the memory is exhausted during the calculation the solver will inevitably quit with an error message This solver works at very high speed for medium struc tures 100 000 1 000 000 DOF because it is multi processor compliant but needs more memory than the iteration solver by several orders of magnitude Therefore this solver is only really useful on machines with very much memory and 64 bit pointers and integers We rec ommend the 64 bit version of Z88 Aurora a 64 bit Windows operating system and a mini mum of 4 GByte 8 or 16 Gbyte are even better of memory for this solver When using a 32 bit operating system and 4 GByte of memory you are limited to structures with 150 000 DOF The actual solver core used is PARDISO by O Schenk University of Basel Switzer land Define the number of CPUs in Z38MANAGE TXT The values preceding have no sig nificance they must be there however Please take care that in the Windows settings
36. of this genre also in the PC class you will have already calculated the first examples with Z88 Aurora And the online help is always only one keystroke or mouse click away The Z88 system may operate with English or German language depending on your setting ENGLISH or GERMAN in the options menu In addition to this Theory Manual there are a User Manual an Example Manual an Installa tion Manual and video sequences available If you already have FEA experiences you can start at once If you are a beginner in this area I would recommend secondary literature Here are a few choices e Zienkiewicz O C Taylor R L The Finite Element Method Volumes I 3 5 edition But terworth Heinemann and John Wiley amp Sons 2000 e Bathe K J Finite Element Procedures Prentice Hall 1995 e Rieg F Hackenschmidt R Finite Elemente Analyse f r Ingenieure Carl Hanser Verlag M nchen Wien 2009 3rd edition in German language The Z88 website www z88 de Give us your feedback Professor Dr Frank Rieg Bayreuth December 2010 Lehrstuhl Konstruktionslehre und CAD Chair for Engineering Design and CAD Faculty of Engineering Science University of Bayreuth Germany frank rieg uni bayreuth de www uni bayreuth de departments konstruktionslehre LIB Theorie Manual LICENSE Software Products Z88 Aurora Software as delivered Software Licensor Chair for Engineering Design and CAD LCAD This is a legal agreement betw
37. on the interface to ap ply boundary conditions 1 e boundary conditions and loads But you can also apply them in Aurora of course You can find the respective overview of the model data which you can adopt in tables 1 4 and 5 Please refer to table 1 in chapter 2 for information about the pos sible element types As expected the pure geometry interfaces only contain the function to import a three dimensional image without FE information 56 LOS irscova Table 4 Model data which can be transferred from FE structure data Z88V 13 DAE ABO AN gt ae NASTRAN Theory Manual FE structure FE super structure Material laws Point loads Boundary Conditions Area loads Solver options Z8814 TXT x x Ecce r A o n TA y a 6G Aurora Theorie Manual 4 1 1 IMPORTING FILES FROM PREVIOUS Z88 VERSIONS UP TO V13 What is the basic idea and which are the features Downward compatibility is one of the basic prerequisites for the effective application of a simulation system Who ever wants to revise their models every six months Therefore all input files from previous versions can be used in Z88 Aurora If necessary only a few small adjustments must be made Which Z88 versions can cooperate with Z88 Aurora As a matter of principle every input file from from every previous version can be imported The function is mainly intended for the import of files from version 13 Therefore older files must be updated to
38. processor contains ZSS8I4 TXT or Z88NI TXT input file of the mesh generator Z88N 24 Z66 Aurora 126 Theory Manual 3 1 1 GENERAL STRUCTURE DATA Z8811 TXT In Z8811 TXT the geometry and material data of the structure are deposited 1 input group General data in the first line contains general structure data Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long 1 number Dimension of the structure 2 or 3 2 number Number of nodes of the FEA structure 3 number Number of elements 4 number Number of degrees of freedom 5 number Number of material information lines 6 number Coordinate flag KFLAG 0 or 1 7 number Beam flag IBFLAG 0 or 1 8 number Plate flag IPFLAG 0 or 1 9 number Surface and pressure loads flag IOFLAG 0 or 1 A Not contained in Z88 Aurora generated Z8811 TXT 10 number Shell flag IHFLAG 0 or 1 Explanations KFLAG At input of 0 the coordinates are expected Cartesian while at input of 1 polar or cylindrical coordinates are expected The latter are then converted into Cartesian coordinates and there upon stored in this form in Z8800 TXT Caution The axially symmetric elements No 6 8 12 and 15 positively expect cylindrical co ordinates set KFLAG to 0 here IBFLAG If Beams No 2 or Beams No 13 appear in the structure then set beam flag IBFLAG to 1 oth erwise it must be 0 Example A three dimensional st
39. produce worse numbering 4 Number of CPUs to be used during calculation Iterative solvers Max iterations 10000 Important for huge FE structures Residuum 1e 007 Sum of error to analytic result alpha SiC 0 0001 Shift factor for partial Cholesky decomposition recommended 0 0001 0 000001 omega SOR 1 1 Factor for successive overrelaxation SOR recommended 0 8 1 2 Direct solver Pardiso O0C memory MB 1000 Memory used in out of core mode ry ry Swap directory amp Main C v Directory for swap file used in out of core mode teans Figure 26 Solver menu or extended options with Cuthill McKee program 4 3 The mapped mesher S mesh generator ZSSN 4 3 1 GENERAL REMARKS The mesh generator Z88N from Z88 is integrated into Z88 Aurora with all functionalities It can produce 2 dimensional and 3 dimensional Finite Element structures from super struc tures The mesh generator input file 1s imported and the general structure data displayed It is accessed in the preprocessor menu via the icon S Superelemente Create FE structure Bx menu preprocessor mm Fbeamstnsses Mesh generation free mesher mapped mesher Ay tetrahedron super elements Z88N mesh generator Parameters of elements Define Material JI Database J gt Define Constraints 2 Apply constraints Loadcases dp Add a Remove loadcase 1 lcl calculate loadcases all Figure 27 Men
40. to Z88 Aurora without reboot The file Z88 DYN can also be edited manually by experienced users The important thing is that certain keywords remain in any case Blank lines or comments are optional only the up percased keywords are recognized After the keyword follows an integer value separated by at least one blank The order of the keywords is optional There are no limits for the size of the structures for Z88 The maximum size is limited only by virtual memory of your computer and your imagination However for very large structures you may use Z88 with 64 Bit integers and pointers i e the 64 Bit versions for Windows and Mac OS X to avoid overflows of internal loop counters 48 a 56 Aurora Theory Manual et A E o i a a RARO PIT epee Lis General Memory 1 memory 2 paths view paths view Structure Analysis of a FE structure Number of nodes MAXK 500000 Choose z88i1 txt Number of elements MAXE 300000 None Coincidence MAXKOI 3000000 Creation MAXSTRUGEOELE 1000 Mapped mesher MAXMMREG fooo ti isS S Geometry import MAXSTLK 50000 ts Faces of faces of elements MAXOTE 300000 Number of bodies MAXPRT Constraint Number of loadcase MAXLASTF 1 Visualisation Number of Gauss points MAXGP z000 S Parts of histogram MAXSTAT C Number of frequencies MAXFREQ 2 0 Subprograms Degrees of freedom MAXNFG s00000 t i CO s s S
41. under a valid CAD name e g at AutoCAD name DWG and work with the drawing You can switch off and switch on the dif ferent Z88 layers as you like 4 1 7 Z88X IN DETAIL Proceed in the following steps and reserve the following layers Z88GEN Layer for general information 1st input group in the mesh generator input file Z88NI TXT and general structure data file Z8811 TXT Includes further the material infor mation 4th input group in the mesh generator input file Z88NI TXT and general structure data file Z8811 TXT Add if necessary the data of the stress parameter Z8813 TXT Z88KNR Layer including the node numbers Z88EIO Layer including the element information like element type and in the case of mesh generator input file Z88NI TXT control information for the mesh generator Z88NET Layer containing the mesh which was drawn or outlined in defined order Z88RBD Layer containing the contents of the boundary conditions file Z8812 TXT Z88FLA Layer containing the surface and pressure loads as defined for Z88I5 TXT A further layer Z88PKT is produced by Z88X if you convert from Z88 to CAD It shows all nodes with a point marker in order to better recognize the nodes For the reverse step from CAD to Z88 it is completely insignificant 1st step Design your component in the CAD system as usual You do not need to maintain a definite order and you can use any layers It is highly recommended to put symbols on one layer edges on another
42. uses internally double precision floating point numbers Double Right l 345 5 5555E 10 0 Wrong l 345 O letter O no entry Z88 input files may have comments in every line if all corresponding data has been filled out before Separate the last data and the comment at least by one blank Lines in Z88 input files can include 250 bytes really needed are noticeably less than 80 Blank lines and pure com ment lines are not permitted Problems which often occur when editing text files e Are the files really pure text files well in the ASCII format e Have hidden control characters been added by your text processor without being noticed e Is the last line of an input file terminated by at least one RETURN 23 LIB or Theorie Manual e Is your structure statically determined or in any way statically over defined allowed Statically undetermined structures can appear easily for Beams No 2 Cams No 5 and Beams No 13 e Is the coincidence list defined properly Especially Hexahedrons No 10 are very sensitive to wrong numbering Z88 input files for UNIX and Windows have the same structure You may load without re striction Z88 UNIX files into Windows and vice versa 3 1 Creating input files Z88 Aurora is a pre and postprocessor for Z88 As a matter of principle the user can gener ate the desired calculation model completely in Z88 Aurora Users who already know Z88 however are supposed to get the possibility to edit the input fi
43. viscoelastic Deformation Plasticity Damping Expansion Brittle Cracking ing degrees of freedom Mesh Controls xX Element Shape Technique A a e Medial axis Free Z Minimize the mesh transition fio Structured amp Advancing Front Sweep Bottom up i Multiple Redefine Sweep Path OK Defaults Cancel 5 Figure 24 But the converter 1s also capable of processing the conditions Pinned and Encastre As possible loads please use the types Concentrated Force and Pressure Algorithm Use mapped meshing where appropriate Notes Z88ainp processes all loads existing in the ABAQUS file Should you have defined several simulation steps Steps in your CAE please keep in mind that if you want to export only one calculation step 1t would be best to generate a new model by copying where all simulation steps except the desired one are deleted If you do not use ABAQUS in connection with TOSCA you must comment out the option nopartscae in your environment file because the input file will be heavily altered With this option only node and element data can be transferred 6 Write the input deck as inp file 7 In Z88 Aurora select File gt Import gt ABAQUS data In the subsequent selection box you can only select Inp files Therefore select the desired file figure 8 The converted structure is displayed and boundary conditions and loads of Z88 Aurora can be displayed Us
44. your drawing 6 1 general information 1 e the first input group of the general structure data Z8811 TXT or the mesh generator file Z88NI TXT In case of Z8811 TXT i e FE mesh ZSS11 TXT Dimension of the structure Number of nodes Number of finite elements Number of degrees of freedom DOF Number of material information lines Coordinate flag 0 or 1 Beam flag 0 or 1 Plate flag 0 or 1 Surface and pressure loads flag 0 or 1 Shell flag 0 or I 2 3 4 Write into one line separate each item by at least one blank Definitely write in the layer Z88GEN Example 3 dimensional FE structure with 150 nodes 89 finite elements 450 degrees of freedom 5 material information lines Input with Cartesian coordinates structure contains neither beams No 2 nor beams No 13 Thus Z88 TXT 3 150 89 4505000 1 In case of Z88NI TXT i e super structure ZSSNILTXT Dimension of the structure Number of nodes Number of super element Number of degrees of freedom DOF Number of material information lines Coordinate flag 0 or 1 Beam flag must here be 0 Plate flag 0 or 1 Surface and pressure loads flag 0 or 1 Trap radius header flag most 0 Coordinate flag output 0 or 1 Write into one line separate each item by at least one blank Example 2 dimensional super structure with 37 nodes 7 super elements 74 degrees of free dom one material information line Cartesian coordinates no beams forbidden anyway in the
45. 1 TXT 0 Calculation of stresses in the corner nodes 1 4 5 Calculation of stresses in the Gauss points e g 4 4 Gauss points gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces pressure loads applied onto element no 16 gt Element number with pressure load gt Pressure positive if pointing towards the edge gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view The local nodes 1 to 6 may differ from the local nodes 1 to 6 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 123 LIB Theorie Manual 517 TETRAHEDRON NO 17 WITH 4 NODES y This is a volume element with linear shape functions The transformation is isoparametric The integration is carried out numerically according to Gauss Legendre Thus the integration order can be selected in Z88I1 TXT in the material information lines The order 1 is good T
46. 1s easier to enter pressure loads via the surface and pressure loads file Z8815 TXT Z X The nodal numbering of the element No 16 must be done carefully and must exactly match the sketch below Pay attention to the location of the axis system The possible error message Jacobi determinant zero or negative is a hint for incorrect node numbering Tetrahedron No 16 cannot be generated by the mesh generator Z88N A DXF data exchange with Z88X is not implemented because tetrahedrons due to their strange geometry are very difficult to arrange in space This element s main purpose is the use with automeshers from third party suppliers Caution Sometimes the automeshers of CAD systems produce very bad element and nodal numbering resulting in an useless large amount of memory needs of Z88F In this case renumber especially the nodes Input Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt IOFLAG 1 if pressure loads for this element are filed in Z8815 TXT gt 3 degrees of freedom for each node gt Element type is 16 122 Zod Aurora 126 Theory Manual gt 10 nodes per element gt Cross section parameter OPARA is 0 or any value has no influence gt Integration order INTORD for each mat info line 4 is usually good Allowed are 1 for 1 Gauss point 4 for 4 Gauss points and 5 for 5 Gauss points 78813 TXT gt Integration order INTORD for stress calculation Can be different from INTORD in Z881
47. 2 Cosmos File z Z88 File 7 1 Tom A Desktop Beispiele test Recently Used E gt Tom gt Desktop is Main C ld DVD RW Laufwerk D 8 BD ROM Laufwerk F 2 DVD RWeLaufwerk conversion of DXF FE Mesh to 288i1 txt conversion of DXF FE Mesh and constraints to i txt iq conversion of DXF superstructure mesh to z88ni txt conversion of DXF superstructure mesh to z8811 txt 0K X cancel Figure 20 Accessing the DXF converter ZS8X and import options in Z88 Aurora Which elements are supported by the converter All element types from 1 to 24 except Tetrahedrons 16 and 17 Which functions does the converter offer Import functions of the converter Z88X gt Conversion gt from Z88X DXF to Z8811 TXT Z88X gt Conversion gt from Z88X DXF to Z881 TXT Z88X gt Conversion gt from Z88X DXF to ZSSNI TXT Export functions of the converter Z88X gt Conversion gt from Z88I1 TXT to Z88X DXF Z88X gt Conversion gt from Z881 TXT to Z88X DXF Z88X gt Conversion gt from ZSSNI TXT to Z88X DXF Since the converter is completely compatible in both directions you can execute these possi bilities in succession as often as you wish You will not find any data loss That makes a most interesting variant Mixed Operation e g Component and super structural layout done in CAD program 63 1288 Theorie Manual Conversion CAD gt Z88 Meshing in Z88 Conversio
48. 34 206000 0 3 2 18 A Z88 Aurora was extended by a material data base This is why the material data are now deposited in Z88MAT TXT which again refers to a material file in csv format When importing an existing Z88 file via the Import function Z3S8MAT TXT is created automatically Subsequent changes to Z8811 TXT however are not considered any more after the import You will find the description of Z88MAT TXT further on in this chapter A 788 Aurora possesses its own definition file for beams and plate information This Z88ELP TXT can also be created automatically from an existing Z8811 TXT Changes which are made in Z88I1 TXT after the import are not considered 28 Zod Aurora 126 Theory Manual 3 1 2 MESH GENERATOR INPUT FILE ZSSNI TXT The layout of Z88NI TXT is very similar to the layout of Z8811 TXT the input file for the FE processor Only the amp labelled data is required in addition Mind the following formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point Character A letter 1 input group Ist number Dimension of the structure 2 or 3 2nd number Number of nodes of the super structure 3rd number Number of super elements 4th number Number of degrees of freedom Sth number Number of material information lines 6th number Coordinate flag KFLAG 0 or 1 7th number Beam flag IBFLAG must be 0 here Sth number Plate flag IPFLA
49. 39
50. ANE STRESS ELEMENT NO 11 WITH 12 NODES This 1s a curvilinear Serendipity plane stress element with cubic shape functions The trans formation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Thus the integration order can be selected in Z8811 TXT in the material information lines The order 3 is mostly the best choice This element calculates both dis placements and stresses with outstanding precision The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an over view or calculated in the Gauss points substantially more exactly Because of its 24x24 element stiffness matrices the element No 11 needs a lot of memory and computing power Pay attention to edge loads when using forces cf chapter 3 4 It 1s easier to enter edge loads via the surface and pressure loads file Z88I5 TXT Plane Stress Elements No 7 can be generated by the mesh generator Z88N from super ele ments Plane Stress Elements No 11 Thus the Plane Stress Element No 11 1s well suited as super element But Plane Stress Elements No 11 cannot be generated by the mesh generator Z88N from super elements Plane Stress Elements No 11 Input CAD see chapter 2 7 2 1 5 6 2 7 8 3 9 10 4 11 12 1 7881 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt IOFLAG 1 if edge loads for this element are filed in ZSSI5 TXT gt 2 degrees of freedom
51. BZ Remove FE structure BZ Remove FE structure Import lal SE Geometry STP STEP eer E set gt si stl files STL Apu E eter Exit DF DXF files DXF Exit F ABAQUS INP NASTRAN files BDF NAS Image BMP E ABAQUS files INP ANSYS files ANS COSMOS files COS es Z88 files TXT Figure 13 Import and export in the text menu 55 Ue Theorie Manual Bu 238 Aurora VI File View Preprocessor Solver Postprocessor Help HOA SEE COCON tht est gd 30 vew import geometry FE structure E STEP File Y Nastran File D STi ll fy Abagus File import export import geometry FE structure HE STEP File Y Nastran File Bette CCT W DXF File Ansys File 2 Cosmos File Ze Z88 File Export Geometry FE structure Export STL f Abaqus export BE Export DXF Project directory CUsersiTomiDesktop Bespieleltest Figure 14 Import and export via the toolbar Depending on the range of functions of the converter a multitude of FE model data can be imported or exported You have the possibility to generate a complete FE structure or a super structure which can be meshed further by means of the integrated mapped mesher Z88N The finite elements of the source program are properly transformed into the corresponding type in Z88 Aurora and material data can be adopted According to the contents of the original data it is possible depending
52. ES EP ooo cccceeccecceccscceccescescescencs 106 TORUS NO 8 WITH 8 NODES g EEN AEA EN E EE OAN EE TE EEN cee TT 108 TRUSS NO 9 IN a a S EN parse E AE EPA E E AEE A 110 HEXAHEDRON NO 10 WITH 20 NODES ty PEI A tetas E IE AX 111 E PLANE STRESS ELEMENT NO 11 WITH 12 NODES LW 0 cecceccnscesceecees 113 TORUS NO 12 WITH 12 NODES Ds O sees eens esi see 115 BEAM NO 13 IN PLANE BF RT 117 ES PLANE STRESS ELEMENT NO 14 WITH 6 NODES HP ono nconcnnonnonnonnnconcnnacncnoncnonns 118 de TORUS NO 15 WITH 6 NODES e cooccccconcconccnnconcconcnnnconoconocnnconoconccnnronaronncnnronnconncnnrnnaconacons 120 TETRAHEDRON NO 16 WITH 10 NODES A ies 122 TETRAHEDRON NO 17 WITH 4 NODES P l occ cococononononnnononnnnnononononononnnononononnnnnnananananonoss 124 PLATE NO 18 WITH 6 NODES y aE E NANE II AEN AE E NEN A E EN E AE 126 PLATE NO 19 WITH 16 NODES y O N AA EAN E A EEE AAA AN 128 PLATE NO 20 WITH 8 NODES y A E Sassen he eat newtansuene et eeenns tases 130 SHELL NO 21 WITH 16 NODES FR APN CRT RUI 132 SHELL NO 22 WITH 12 NODES FR aceites 134 SHELL NO 23 WITH 8 NODES FA A tage aise EA E eas denen ote ete 136 SHELL NO 24 WITH 6 NODES FR a 138 o hzor Theory Manual 1 THE FINITE ELEMENTS PROGRAM Z88 Aurora ay 788 Aurora V1 Filo View Preprocessor Solver Postprocestor Help GOA HEA GAO CHL k 9 38 STGO FAO FO E AN FF Teyi statistics 4 00E 00 6 5964001 5 552001 SIE 1 JIE See 1 SEH 2 BoE He EAU vA A SEH
53. G 0 or 1 9th number Surface and pressure loads flag IOFLAG 0 or 1 10th number Shell flag IHFLAG 0 or 1 amp 10th number Trap radius flag NIFLAG 0 or 1 amp llth number Coordinate flag KFLAG 0 or 1 Write all numbers into a line separate at least by one blank respectively All numbers here of the type Long Explanations KFLAGSS At input of 0 the coordinates are expected Cartesian while at input of 1 polar or cylindrical coordinates are expected The latter are then converted into Cartesian coordinates and there upon stored in this form in Z8811 TXT Caution The axially symmetric elements No 8 and 12 positively expect cylindrical coordinates set KFLAGSS to 0 here IPFLAG If Plates No 20 appear in the structure then set plate flag IPFLAG to 1 otherwise it must be O IOFLAG Y ou may set here IQFLAG 1 as a reminder if you plan to define a surface and pressure loads file Z88I5 TXT However IQFLAG has no effect for the mesh generator NIFLAG In order to identify already defined nodes the mesh generator needs a trap radius The defaults are 0 01 for for EPSX EPSY and EPSZ if NIFLAG is 0 These values can be modified at ex tremely small or large structures To initiate this change set NIFLAG to The new trap radi uses of EPSX EPSY and EPSZ are then defined in Z88NI TXT as the 6th input group Example Super structure 2 dimensional with 37 nodes 7 super elements 74 degrees of freedom one material informati
54. Manual WELCOMES TO Z88 Aurora Z88 is a software package for solving structural mechanical static problems with the aid of the Finite Element Method FEM which 1s available under GNU GPL as free software with source code The software was originally developed by Professor Frank Rieg in 1986 In addition to the present compact Z88 which is currently available in the 13 version an ex tended program Z88 Aurora is developed by a team of ten under the supervision of Professor Rieg since 2009 Z88 Aurora is based on Z88 and is available for Windows 32 BIT and 64 BIT for free download as executable file A MAC OS X version will follow soon In addi tion to the efficient solvers contained in Z88 Z88 Aurora offers a graphic user interface a completely new preprocessor and an extension of the approved postprocessor Z880 In the development of Z88 Aurora great importance was attached to intuitive operation The present version Z88 Aurora offers in addition to static strength analyses a material data base containing more than 50 established construction materials Further modules such as non linear strength calculations natural frequency analysis contact and thermal analyses are under development Z88 does not want to compete with professional FEA programs for workstation or main frames which can do really everything but are hardly payable and complicated to operate While you are still puzzling about installation and start of some programs
55. N77 program of Professor Schwarz and is specially adapted to Z88 The core algorithm of H R Schwarz decides internally whether to use the normal Cuthill McKee procedure or the reverse Cuthill McKee algorithm The Cuthill McKee program Z88H integrated in Z88 Aurora was originally designed for fi nite element meshes generated by 3D converter Z88G However Z88H can deal with all Z88 meshes Z88H reads the Z88 input files Z8811 TXT general structure information and Z8812 TXT boundary conditions and if needed Z88I5 TXT surface and pressure loads files backups Z8811 OLD Z8812 OLD and Z88I5 OLD if needed and computes the modi fied input files Z8811 TXT and Z88I2 TXT and Z8815 TXT Own research studies showed that sometimes a second run of Z88H may improve again the numbering of a first run of Z88H A third run seems to make things slightly worse again In extreme cases the Cuthill McKee algorithm 1 e Z88H may sometimes compute counterpro ductive results 1 e worse nodal numbering than the original mesh You should have some experiments because the Cuthill McKee algorithm may not always improve a given mesh You find the Cuthill McKee program in the menu Solver under Extended Options 90 a 56 Aurora Theory Manual EH menu solver Em Stress parameters von Mises stresses he Compute 2x2 x2 Gauss points v No results RUN Cuthill McKee Z88H General fi Warning Repeated node sorts may
56. OOLBAR_ PRE 0 SCROLLER 150 ROTATOR i TRANSLATOR 1 ZU externen Programmen P01 ACROBAT CER P02 PLAYER Co P03 BROWSER Cr Figure 11 Example ZSSENVIRO DYN Lines which are preceded by a hashmark are ignored by Z88 Aurora They are meant to be assistance to the reader of the file Behind WORKPATH there is the project directory which you are currently working on Behind ADDONS you find the paths of additional modules The flags listed in Table 3 are marked by the preceding keyword FLAG They can be changed under Help gt Options in the tab View see Figure 2 Behind PATH you find the paths of external programs which can be automatically ac cessed for example to visualise the support If no path is preset C 1s used as standard These paths as well as all other settings of Z88ENVIRO DYN can be modified under Options in the menu Help see Figure 12 Experienced users can edit them directly in the file 53 Theorie Manual f a Figure 12 Flags for the standard view left and the path settings right 54 Plato Aurora v s Theory Manual 4 THE Z88 MODULES Note Always compare FE calculations with analytical rough calculations results of ex periments plausibility considerations and other tests without exception 4 1 Interfaces and file converters for CAD and FE programs Z88 Aurora offers the possibility to import a multitude of established file formats from com mercial simulation programs pure geom
57. PARA is the element thickness Z8813 TXT gt Integration order INTORD any order has no influence gt KFLAG 0 Calculation of SIGXX SIGYY and TAUXY gt KFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses in the centre of gravity 2 principal or Rankine stresses in the centre of gravity 3 Tresca stresses in the centre of gravity Results Displacements into X and Y Stresses The stresses are calculated in the element s centre of gravity The coordinates of the centre of gravity are thus printed For KFLAG the radial stresses SIGRR the tangential stresses SIGTT and the accompany ing shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the centre of gravity are printed Optional von Mises stresses in the centre of gravity Nodal forces in X and Y for each element and each node 102 Zod Aurora 56 Theory Manual s4 TRUSS NO 4 IN SPACEY The truss element No 4 can take any location in space It is part of the simplest elements in Z88 and is calculated extremely fast The truss elements match Hooke s law exactly Z Input CAD see chapter 2 7 2 Line from node I to node 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt 3 degrees of freedom for each node gt E
58. S What is the basic idea and which are the features Apart from NASTRAN and COSMOS Pro ENGINEER also supports the output of simula tion data as ANSYS file ans These data can subsequently be transmitted to ANSYS as well as to Z88 Aurora Please keep in mind however that this data format can also be arbi trarily altered by the producer which might lead to compatibility problems 79 Ue Theorie Manual DOA SHEBA COAH CL k 480 A import lt gt menu import export gt geometry FE structure SP STEP File Nastran File 2 STL File 4 Abaqus File Ansys File DE DXF File es Z88 File Figure 23 Accessing the ANSYS converter ZSSANS A solid with any number of materials linear elastic can be converted The solid must consist of one element type Optional Cartesian boundary conditions concen trated forces and forces on areas as well as pressures can be applied CAUTION z88ans directly generates the mat csv data for Z88 Aurora from the material in formation in the source file Into Z8811 TXT only reduced material information is entered with Young s modulus and Poisson s ratio each set to 0 Which ANSYS files systems can be imported by Z88 Aurora ANSYS data can possess very different structures and contents depending on their origin That is why accurate statements about compatibility cannot be made Especially integrated scripts can cause problems This converter was developed an
59. TE This file is described more precisely in chapter 3 Explanations to the sparse matrix iteration solvers SICCG and SORCG An iteration solver uses only the so called non zero elements which results in an absolute minimum of storage requirements It builds the following pointers for the lower part of the total stiffness matrix GS e Pointer vector IP points to the diagonal elements GS 1 e Pointer vector IEZ points to the column index GS x J Example ref Schwarz H R Methode der finiten Elemente Let the lower part of GS be Zod Aurora 56 Theory Manual GS results in the following vector of non zero elements GS 5 1 GS 5 3 GS 6 5 GS 6 2 GS 6 4 GS 6 IEZ will result in PER PBEBEB EP fe and IP The pointer IEZ holds MAXIEZ elements the vector GS holds MAXGS elements These lim its are determines in the test mode of the solver In the second run the actual computation run the solver computes the element stiffness ma trices compiles the total stiffness matrix incorporates the boundary conditions scales the system of equations and solves the huge system of equations by the conjugate gradient algo rithm Preconditioning is done for better convergence You can choose whether to use a SOR step or a so called incomplete Cholesky decomposition for precondition Default is the incomplete Cholesky decomposition shifted incomplete Cholesky decomposition SIC be cause the main parameter the so called shif
60. TXT This file is optional and only used if in addition to nodal forces edge loads applied onto element no 12 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and 2 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 4 may differ from the local nodes 1 2 3 4 used for the coincidence Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises or principal or Tresca stresses Nodal forces in R X and Z Y for each element and each node 116 Z Aurora 56 Theory Manual 513 BEAM NO 13 IN PLANE Y Beam element with any symmetric profile The profile values are provided in Z8811 TXT Thus you can use any symmetric profile in contrast to other FEA programs which sometimes incorporate a variety of different special beam and profile subroutines without matching all symmetric profiles as necessary The element matches exactly Bernoulli s bend theory and Hooke s la
61. Theory Manual 288 Aurora Vi Bib Wiee Pregraciior Gober Poroci Hp CENTS AA EA AA MA SECO NAF FO PE AR SE view Seatanes 4 000 001 8 See so 4 S020 1 ond 1 RAO 1 57 i TEO 564107 DESEAS 3 SHO JTE 05500 445004000 4 BREA SBE 0G 5 ME HO E 6 SEA 45 206000 HEME 6 24000 47 308 aoe wee See in Sl Gaye paria Simetun FE View Sobel all element ject directory C pSgaurora loo bea bon 160 6 aa Mas scaling factor 1000 apply Magr icatore Dispilacinnants X es ta i Y es ta i ee Magro of daplacorm rids ih Af torre oe kh per almera Modal forces Y as Version Vla An easily operated user interface for Z88 for all Windows and Mac OS X Computers for 32 and 64 bit This Freeware Version is the literary property of the Chair for Engineering Design and CAD University of Bayreuth Germany composed and edited by Professor Dr Ing Frank Rieg with the aid of Dr Ing Bettina Alber Laukant Dipl Wirtsch Ing Reinhard Hackenschmidt Dipl Math Martin Neidnicht Dipl Ing Florian Niitzel Dr Ing Bernd Roith Dipl Ing Alexander Troll Dipl Ing Christoph Weh mann Dipl Ing Jochen Zapf Dipl Ing Markus Zimmermann Dr Ing Martin Zimmermann All rights reserved by the editor Version la December 2010 GG Aurora og is a registered trademark No 30 2009 064 238 of Professor Dr Ing Frank Rieg Z66 Aurora 126 Theory
62. ace and pressure loads are supposed to be applied to elements No 24 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view Y Shell No 24 with pressure load Simplified procedure for Shells No 23 and No 24 If a pressure affects a whole element group this pressure can be specified simplified in the section Material information of Z8811 TXT like in the case of plates 4 input group starting after last element contains Material information 1 line for each material information This material information line starts with element no inclusively Long This material information line ends with element no inclusively Long Young s Modulus Double Poisson s Ratio Double Integration order Long Cross section value OPARA Double gt Surface load Double For this the shell flag IHFLAG must not be 0 and at the same time the surface load flag must be 0 42 Hah Aurora 1268 Theory Manual A MATERIAL FILE Z88MAT TXT Because of the extension by a material database the material data in Z88 Aurora are stored in a separate file When importing an existing Z8811 TXT the material information is extracted and automatically transferred into Z88MAT TXT Editing Z88I1 TXT later is possible the information however is not taken over by Aurora workaround reimporting The file merely consists of an in
63. ace and pressure loads file Z88I5 TXT This element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology Thus a mesh generation with Z88N is not possible Use torus elements No 8 for Z88N Use torus element No 8 whenever possible It is substantially more precise than this isoparametric triangle Input CAD see chapter 2 7 2 1 4 2 5 3 6 1 Z8811 TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt IOFLAG 1 if edge loads for this element are filed in ZSSI5 TXT gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 15 gt 6 nodes per element gt Cross section parameter OPARA is 0 or any value no influence gt Integration order INTORD per each mat info line 7 is usually good Possible is 3 for 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy use with torus element No 68 e g with Pro ENGINEER function ISOD88 of Z88 uses internally these values integration order 1 or 2 in Z8811 TXT 3 Gauss points integration order 4 in Z8811 TXT 7 Gauss points Example Z8811 TXT uses an entry of 2 for INTORD Thus torus elements No 8 use 2x2 4 Gauss points and torus elements No 14 use 3 Gauss points for integration 78813 TXT gt Integration order INTORD Basically it is a good idea to use the same value
64. ally and positive in local s direction with 300 N mm Thus gt 456 100 200 300 351 34 99 12 102 151 166 191 Tetrahedron No 17 Element number with pressure load Long Pressure positive if pointing towards the surface Double 3 nodes of the loaded surface 3 x Double Example The tetrahedron 356 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 and 12 The surface load is pressure with 100 N mm pointing towards the surface 1 e positive Thus gt 356 100 51 34 12 Tetrahedron No 16 Element number with pressure load Long 39 Us Theorie Manual Pressure positive if pointing towards the surface Double 6 nodes of the loaded surface 6 x Double Example The tetrahedron 888 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 and 12 and the mid nodes 65 66 and 67 The sur face load 1s pressure with 100 N mm pointing towards the surface 1 e positive Thus gt 888 100 51 34 12 65 66 67 Tetraeder with pressure load on one element side Plate elements No 18 19 and 20 Element number with pressure load Long Pressure positive if pointing towards the surface Double It 1s easier to enter the pressure loads for plate elements directly into the structure file Z8811 TXT than via Z8815 TXT Shell No 21 This file is optional and is only used if in addition to nodal forces surface and pressure loads are supp
65. ample shall clarify the facts wrong distribution of load 14286 142 86 142 86 142 86 14286 14286 142 86 element 1 element 2 element 3 right distibution of load 55 55 222 22 111 11 222 22 111 11 22222 66 56 element 1 element 2 element 3 Figure 3 Correct load distribution on the nodes An FE structure consists of three plane stress elements No 7 with the load of 1 000 N distrib 35 LIB Theorie Manual uted on the upper edge in Y direction Above incorrect below correct load sharing Incorrect 1 000N 7 142 86 N per node Not correct for elements with square shape function Correct 2 x 1 6 2 x 1 6 1 6 3 x 2 3 18 6 3 corresponds to 1 000 N 1 6 points 1 000 18x1 55 55 2 6 points 1 000 18x2 111 11 2 3 points 1 000 18x4 222 22 Control 2x55 55 2x111 11 3x222 22 1 000 N o k Here s why 1 4 1 4 1 2 1 2 1 4 H 2 1 4 1 4 ue Figure 4 Elements with linear T functions e g Hexahedron No 1 1 12 1 3 1 12 a a 2 3 1 3 1 3 112 1 12 1 3 1 3 SZ 1 3 1 12 1 12 Figure 5 Elements with quadratic shape functions e g plane stress element No 3 and 7 Torus No 6 bien No 10 1 8 3 16 3 16 1 8 1 8 el 3 8 1 8 3 16 3 16 3 16 3 16 1 8 3 16 3 16 1 8 Figure 6 Elements with cubic shape functions e g plane stress element No 11 Torus No 12 3 1 4 STRESS PARAMETER FILE Z88I5 TXT In Z88 Aurora this file does not have to be explicitly generated any more The same in
66. as chosen in Z8811 TXT but different values are permitted 120 Z66 Aurora 126 Theory Manual 0 Calculation of the stresses in the corner nodes 1 7 13 Calculation of the stresses in the Gauss points e g 7 Gauss points See note for Z8811 TXT gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces edge loads applied onto element no 15 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Q D de t A gt Me Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY
67. at nearly the same speed as the solvers of the large and expensive commercial FEA programs as our tests showed In addition a minimum of storage is needed This solver is your choice for large structures with more than 150 000 200 000 DOF FE structures with 5 million DOF are no prob lem for it 1f you use a 64 bit operation system Windows or LINUX or Mac OS X along with the 64 bit version of Z88 and about 6 GByte of memory This very stable and approved solver works always thus you may use it as your standard solver In Z88 Aurora the solver types are selected via the solver menu q menu solver gt Solvertype SICCG sparse iterative i gt Cholesky direct SICCG sparse iterative Stress parameters SORCG sparse iterative Pardiso sparse direct von Mises stresses v Compute 2x2 x2 Gauss points v amp Options No results 3 RUN Figure 1 Solver menu HI THE INTERFACE MODULES TO CAD AND FEA SYSTEMS OF E 2 Z88 Aurora offers the possibility to import a multitude of established file formats from com mercial simulation programs pure geometry data or super structures as well as to continue using existing FE data or CAD data from Version 13 of the Open Source program Z88 Fur thermore data can be exported in different formats Each of these converters offers an individ ual range of functions and its own setting options if necessary In chapter 4 1 the single func tions of the auxiliary programs as well as
68. ation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element the shell flag IHFLAG must be set to 0 or 1 in the first line of Z8811 TXT In case of thin shells set IHFLAG to 2 or 3 In case of very thin Shells set it to 4 If IHFLAG is not 0 a surface load can be imported simplified into the mate rial entries In this case the surface load flag IQFLAG should be 0 The first three degrees of freedom are the global displacements in X Y and Z The degrees of freedom 4 and 5 are the torsions on the respective node degree of freedom 6 is a pseudo DOF without practical significance Only the global displacements in X Y and Z are practically useful and of interest Input CAD 4 2 5 3 6 1 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt Set shell flag IHFLAG to 0 or I analogously to 2 or 3 in case of thin shells to 4 in case of very thin shells If IHFLAG is not 0 a surface load can be imported simplified into the material entries in Z8811 TXT via the Second moment of inertia RIYY Otherwise the Second moment of inertia RIYY is set to 0 gt surface and pressure loads flag IQFLAG 1 if entry of surface and pressure loads via ZS8I5 TXT gt 6 degrees of freedom for each node gt Element type is 24 gt 6 nodes per element gt Cross section parameter OPARA is the element thickness gt
69. ation order can be selected in Z88I1 TXT in the material information lines The order 7 7 Gauss points 1s mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surface and pressure loads file Z88I5 TXT This element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology Thus a mesh generation with Z88N is not possible Use plane stress elements No 7 for ZS8N Use plane stress element No 7 whenever possible It is substantially more precise than this isoparametric triangle Y Input CAD see chapter 2 7 2 1 4 2 5 3 6 1 Z8811 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt IOFLAG 1 if edge loads for this element are filed in ZSSI5 TXT gt 2 degrees of freedom for each node gt Element type is 14 gt 6 nodes per element gt Cross section parameter OPARA is the element thickness gt Integration order INTORD per each mat info line 7 is usually good Possible is 3 for 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy use with plane stress element No 7 e g with Pro ENGINEER func
70. ced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 130 Zod Aurora 126 Theory Manual 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and normally not used here because it is much more convenient to enter the pressure data for the plate elements into Z8811 TXT in the section material information However the possibility for entering the pressure loads by the surface and pressure loads file Z88I5 TXT too is implemented for universal use of this file Then set IQFLAG to 1 and proceed as follows gt Element number with pressure load gt Pressure positive if pointing towards the edge Results Displacements in Z i e w and rotations 0 around X axis and 0 around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The following results will be presented O late bending moments M and M unit force x length length late torsion moments M M unit force x length length he shear forces Q and Q unit force length he true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 131 LIB or Theorie Manual 5 21 SHELL NO 21 WITH 16 NODES FR This is a cur
71. ct ENGLISH Between the lines COMMON START and COMMON END there are the memory parameters 50 Mah Aurora 56 Theory Manual MAXKOI determines the number of coincidence nodes This is the sum of the nodes of all elements If for example we deal with a structure consisting of two hexahedrons with eight nodes each connected at four nodes there are 12 nodes MAXK 12 5 17 but 16 coin cidence nodes MAXKOI 8 8 5 17 MAXK Maximum number of nodes in the structure MAXE Maximum number of elements in the structure MAXNEG Maximum number of material info lines for the structure MAXGP determines the maximum number of integration points for the visual display A MAXOTE is the maximum number of surfaces A surface 1s the outwardly visible side of an element Depending on the structure there might be more surfaces than elements A MAXSTRUGEOEL E determines the maximum number of nodes and elements which can be generated by means of the tool Create FE structure gt A MAXSTLK is the maximum number of nodes for imported STL meshes gt MAXMAT is the maximum number of materials which can be saved in the material data base gt MAXMMREG defines the largest possible number of rules for meshing super structures by means of the module Z88N A MAXSTAT is the maximum number of intervals in the statistic function for equivalent stresses tab Statistics of the post processor A MAXNFG defines the maximum number of degr
72. culation is possible A good value for element type 16 is 5 5 Gauss points For element type No 17 a value of 1 could be fine This Ist value has no meaning for element types No 2 3 4 5 6 9 and 13 2nd value For the plane stress elements No 3 7 11 and 14 KFLAG Long O standard stress calculation 1 additional calculation of the radial and tangential stresses 3rd value Choice of the reduced stress hypothesis ISFLAG Long 0 no calculation of the reduced stresses 1 von Mises stresses 2 principal or Rankine stresses 3 Tresca stresses Example 1 The stress processor Z88D is supposed to calculate for a structure of Plane Stress 37 LIB Theorie Manual Elements No 7 the stresses for every finite element into 3x3 Gauss points INTORD 3 In addition to this calculation of standard stresses a calculation of radial and tangential stresses is supposed to be run KFLAG 1 Furthermore compute von Mises stresses ISFLAG 1 gt Thus 3 1 1 Example 2 The stress processor Z88D is supposed to compute only the stresses of the corner nodes for every finite element No 7 Only standard stress calculation thus KFLAG 0 Do not compute von Mises stresses thus ISFLAG 0 gt Thus 0 0 0 3 1 5 PARAMETER FILE Z8814 TXT This file is not needed any longer in Z88 Aurora all information is available in Z88MANAGE TXT which will be described later in this chapter 3 1 6 SURFACE PRESSURE LOADS FILE Z8815 TXT Mind the f
73. curvilinear Serendipity shell element with square shape functions The transforma tion is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre All nodes have to be on a common surface which can be placed arbitrarily in a space which is very useful for the data exchange with 3D CAD systems The integra tion order can be selected in Z88I1 TXT in the material information lines The order 3 i e 3x3 Gauss Points is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly For this element the shell flag IHFLAG must be set to 0 or 1 in the first line of Z88I1 TXT In case of thin shells set IHFLAG to 2 or 3 In case of very thin shells set it to 4 If IHFLAG is not 0 a surface load can be imported simplified into the material entries In this case the surface load flag IQFLAG should be 0 The first three degrees of freedom are the global displacements in X Y and Z The degrees of freedom 4 and 5 are the torsions on the respective node degree of freedom 6 is a pseudo DOF without practical significance Only the global displacements in X Y and Z are practically useful and of interest Input CAD 5 2 6 3 7 4 8 1 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cart
74. d ZS8G A bit tricky but works quite fine For example some lines from a mesh generator input file ZSSNI TXT 5 20 super element 5 of type 20 20 25 27 22 24 26 28 21 5 19 generate from super element 5 which is of type 20 is see above finite elements of type 19 JE 3E _ and subdivide them three times equidistant in X direction and three times equidistant in Y direction Input CAD 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1 ref chap 2 7 2 Usually you will not work in this way It s much easier to build within a CAD program a super elements mesh with 8 node plates No 20 Export this mesh as a DXF file and use Z88X to produce a mesh generator input file Z88NI TXT Run the mesher Z88N and gen erate a finite elements mesh with plates No 19 Plot this mesh using Z88P read off the appropriate node num bers and edit the boundary conditions file Z8812 TXT 128 Z66 Aurora 126 Theory Manual 7880 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to 1 or 2 if you want to reduce the shear influence gt set surface and pressure loads flag IOFLAG to O for your convenience Then the entry of the pressure is done via the Second moment of inertia RIYY see below If IQFLAG is set to 1 then the entry of the pressure is done via the surface and pressure loads file Z8815 TXT gt 3 degrees of freedom for each node w 0 0 gt Element type is 19 gt 16 nodes per element
75. d tested for Pro ENGINEER Wildfire 4 Data generated by means of ANSYS Workbench cannot be imported Which elements are supported by the converter You can use tetrahedrons as linear or as quadratic type Conversion gt from TET 4 to element type 17 and vice versa Conversion gt from TET 10 E 92 to element type 16 and vice versa Which functions does the converter offer Import functions of the converter z88ans Generation gt of Z8811 TXT from an ANSYS file Generation gt of Z8812 TXT from an ANSYS file Generation gt of Z8815 TXT from an ANSYS file Generation gt of MAT TXT from an ANSYS file How to proceed 1 Construct your model according to the instructions for the NASTRAN converter z88g 2 Take care to select the ANSYS format when outputting the simulation data 3 Import the simulation model into Z88Aurora as described in figure XX For this pur pose select File gt Import gt ANSYS file 4 1 10 THE ABAQUS CONVERTERS Z88AINP AND ZSSAEXP What is the basic idea and which are the features If you want to offset the results of a simulation in a second system one of the basic prerequi sites is that you re use as many input data as possible in order to create the same precondi 80 Mah Aurora 56 Theory Manual tions Just like the ANSYS converter Z88AINP and Z88AEXP are supposed to provide an accurate exchange of mesh material and boundary conditions between the single systems By now ABAQUS has become a wide spread
76. ddition you may plot the deflections for X for Y or for Z with colour shading This 1s a pretty nice feature for large spatial structures You may plot the shaded colours for stresses or for the deflections or the hidden line display or the wire frame display with the deflected structure The background colours and legend display can be adjusted For further information refer to the Z88 Aurora User Manual By means of a scrollbar the deflection can also be scaled steplessly 96 Mah Aurora 126 Theory Manual Table 9 Combination of the different modes of postprocessing A eee A A AA Wire Frame Stresses in corner nodes sf Stresses in Gauss points f Deflections X NES DeflectionsY DeflectionsZ_ te Le de Tel HE ite Ht iN is The coordinate system OpenGL works with a Clipping Volume i e with a kind of cube defined by Xmin and Xmax in horizontal direction by Ymin and Ymax in vertical direction and Zmin points towards the user and Zmax points away from the user If you use a too large zoom factor or if you are panning the structure too near to you then the range of Zmin is ex ceeded and parts of the structure are lying outside the viewing volume This offers a nice chance to look into a structure also in order to see the internal stresses Otherwise change the value of Zmin default entry is 100 to lower val
77. dge of how OpenGL works if you want to change light effects etc Otherwise there will be long faces because nothing seems to work properly anymore Some hints are included in Z88 FCD in the form of remarks but I cannot give an introduction to OpenGL in this context Please consul for example Rieg F Grafikprogrammierung fiir Windows Carl Hanser Ver lag Miinchen Wien 2005 94 Hah Aurora 126 Theory Manual Table 8 Required data for the display of results Needed Files Super Structures undeflected FE Structures deflected FE Structures Z88NI TXT Z8811 TXT Z8812 1XT yes for displaying the boundary condi yes for displaying the boundary tions conditions 28802 TXT Gauss points yes for displaying the stresses in the yes for displaying the stresses in corner nodes or the average element the corner nodes or the average stresses element stresses Features of rendering For fastest operation Z88 Aurora connects the nodal points in case of scenes with lighting and in hidden line mode and only the corner points with straight lines although for Serendipity elements the edges of the elements are square or cubic curves in wireframe mode all nodes are connected with straight lines Especially illuminated scenes need a huge amount of computational power If a part renders pretty fast in your CAD system Pro ENGINEER for example and the same part renders quite slowly in Z88O this 1s normal business because CAD systems are d
78. e data of your old model In Z88 Aurora select File gt Import gt Z88 files and in the subsequent selection menu select the option General structure data Figure 16 Thus all nodes elements as well as existing material laws are directly transferred If you do not want to apply any pre vious boundary conditions or stress parameters you are already done 2 Importing boundary conditions stress parameters and pressure in succession Select File gt Import gt Z88 Z8812 TXT Z8813 TXT Z8815 TXT Please keep in mind that that you can only select only one file at a time Therefore please repeat this step until all desired data are available 4 1 2 THE STEP IMPORT INTO Z88 AURORA Z88GEOKON STEP What is the basic idea and which are the features The present STEP converter 1s based on the parsing and output routines of the Open Source 3D Suite OpenCASCADE Therefore the relevant sources stepread cpp and geocon cpp as well as a copy of the GPL license accompany Z88 Aurora Most 3D CAD systems possess the possibility to generated models in files according to the international standard DIN ISO 10303 STEP STandard for the Exchange of Product model data In most of these cases the application logs AP203 and AP214 are applied These store the 3D geometry described in highly accurate form in text files At the moment only few CAD producers accommodate the fact that STEP could transfer a lot more notes parameters materials and a lot more
79. e output file Z8811 TXT and KFLAG is set to 1 in Z88I1 TXT 4 4 THE POSTPROCESSOR Structures illuminated with three light sourced wireframe or hidden line structures can be plotted undeflected deflected or both of them overlaying In the same way a colour range for stresses and Y and Z deflections can be displayed In case of node and element numbers ar eas can be specified which 1s very helpful in case of large structures A plotter or printer out put is not explicitly intended Why should it be Simply make a screenshot with Shift Print in the clipboard and edit or print 1t with the Windows program Paint or a paint program such as for example CorelPaint etc Under the Export function it is possible in Z88 Aurora to export the current view as a bmp image 2 Geometry STL D DXF DXF Ej ABAQUS INP Image BMP Figure 30 Exporting the current view as image in Z88 Aurora Z88 Aurora uses OpenGL Therefore your computer must be able to deal with OpenGL In case of the more recent Windows versions this is activated by default and usually a cheap graphic adapter will be sufficient To be on the safe side however check the system settings sometimes OpenGL hardware acceleration can be activated Your choice of colours screen size light features material properties the polygon offset etc can be defined in the file Z88 FCD But be careful with changes in Z88 FCD You must pos sess some basic knowle
80. e the prove mesh of Aurora in order to check the quality of the mesh For the export as ABAQUS file proceed as follows 1 Generate your model in Z88 Aurora You can use all boundary conditions and all con centrated forces 84 Zod Aurora 126 Theory Manual 2 In Z88 Aurora select File gt Export gt ABAQUS data 4 2 The linear solver Z88R The linear solver Z88R includes internally three different solvers e The so called Cholesky solver without fill in with so called Jennings storage It is easy to handle and very fast for small and medium structures However like any direct solver Z88F reacts badly on ill numbered nodes but you may improve the situation with the Cuthill McKee program Z88H for further information and access of Z88H see chapter 4 2 4 Z88F is your choice for small and medium structures up to 20 000 30 000 degrees of freedom Typical application truss and beam models plane contin uum elements e A so called direct sparse matrix solver with fill in It uses the so called PARDISO solver This solver is very fast since it is multi CPU compliant but 1t uses very much dynamic memory therefore the program is likely to quit with an error message if the main memory is exhausted This solver is your choice for medium structures up to 150 000 degrees of freedom on ordinary 32 bit PCs However we ve computed struc tures with 1 million of DOF very fast using a computer featuring 32 Gbyte of memory 4 CPUs
81. eate the mesh with Make Model and choose the element type e g Tet Mesh Store the mesh with Output Model choose NASTRAN or COSMOS M and linear or parabolic the option toggle fix elements is not bad for this pur pose Enter z88g nas for NASTRAN files or z882 cos for COSMOS files for the output file name Then launch the converter Z88G 71 LIB Theorie Manual Choose the file type and specify the element type to be generated Of course both must corre late with what you have previously designed in Pro ENGINEER The background especially of the selection of the element type is that the output of Pro ENGINEER is the type shell even if we deal with plane stress elements tori or plates The converter produces the Z88 in put files Z8811 TXT Z8812 TXT and Z8813 TXT and Z88I5 TXT 1f needed automatically You may then enter the Z88 input files and edit values e g material data and integration or ders 1f necessary Test the Z88 input files generated by Z88G with the filechecker Z88V Plot Z8811 TXT with the plot program Z880 or Z88P If you find a 3D model totally flat You ve defined a coordi nate system CSO in Pro ENGINEER which does not fit Z88 s needs Simply define a new cor rect coordinate system in Pro ENGINEER and define it as datum when outputting the model Keep in mind that those exchange file formats and their Pro ENGINEER output are subject to change every some months You may create the following Z88 element types wit
82. ecause a firm and rigid work sequence must now be kept because of the topological information One of the most important information the coincidence is defined in this step that means which elements are defined or outlined by which nodes Choose a proper colour which differs well from the colours used till now and remove all superfluous information by switching off unused layers Select the LINE command and select the proper snap options e g points intersection points and if necessary end points Start at the first element For Z88 the first element is the element with which you start now that means the one which you have chosen for your first element SE 1 or FE 1 Select the node you want to be the first node of this element this can be e g globally the node 150 and draw a line to the node which shall be the second node of this element this can be e g glob ally the node 67 From there draw a line to the third node of this element this can be e g globally the node 45 Connect all required nodes with lines and draw at last a line to the starting point the first node and then quit the LINE function Then you do the same with the second element Remember You determine with this order which of the elements will be the real second element now In the previous 4th step you have only defined what kind of element the second element is You determine here how the element 1s defined topologically The third element follows and so on If y
83. ection Long 2nd number Type of subdivision of CMODE x Character 3rd number Number of finite elements in local y direction Long 4th number Type of the subdivision CMODE y Character 31 L8G Theorie Manual 5th number Number of finite elements in local z direction Long 6th number Type of the subdivision of CMODE z Character The two values for Z are skipped at 2 dimensional structures Explanations CMODE can accept the following values e E Subdivision equidistant e is also permitted e L Subdivision increasing geometrically in local coordinate direction e Subdivision decreasing geometrically in local coordinate direction The local x y and z axes are defined as follows e Local x axis points in direction of local nodes 1 and 2 e Local y axis points in direction of local nodes and 4 e Local z axis points in direction of local nodes 1 and 5 See following sketch below Example Subdivide an Isoparametric Serendipity Plane Stress Element with 12 nodes Ele ment No 11 into finite elements of type Isoparametric Serendipity Plane Stress Element with 8 nodes Element No 7 Subdivide in local x direction three times equidistantly and subdi vide 5 times increasing geometrically in local y direction The super element is supposed to have the number 31 Thus resulting in two lines 31 11 7 3 E 5 L eorE for equidistant are equivalent amp 6 input group optionally after the end of input group 5 Input g
84. een you the end user and Chair for Engineering Design and CAD Universitaetsstr 30 95447 Bayreuth Germany By installing by downloading or by agreeing to the integrated conditions of this End User License Agreement you are agreeing to be bound by the terms of this agreement If you do not agree to the terms of this agreement promptly return the Software and the accompanying items including written materials and binders or other containers to the place you obtained them for a full refund 1 Grant of license This LCAD license agreement license permits you to use a copy of the Software acquired with this license on any com puter in multiple number of installations The Software is in use on a computer when it is loaded into the temporary memory or installed into the permanent memory e g hard disk CD ROM or other storage device of that computer Bi Copyright The Software is owned by LCAD and 1s protected by copyright laws international treaty provisions and other national laws Therefore you must treat the Software like any other copyrighted material e g a book There is no right to use trademarks pictures documentation e g without naming LCAD 3 Other restrictions You may not rent or lease the Software but you may transfer your rights under this LCAD license agreement on a permanent basis provided you transfer all copies of the Software and all written materials and the recipient agrees to the terms of this agree
85. ees of freedom In case of continuum ele ments for example each node possesses three degrees of freedom Thus you get the number of degrees of freedom by multiplying the number of nodes by the factor three MAXRBD is the maximum possible number of boundary conditions which can be applied MAXPR defines the maximum number of pressure loads which can be applied E 51 Us Theorie Manual 3 1 11 A DEFINITION FILE Z88ENVIRO DYN Z88 Aurora includes a project file management While working with Z88 Aurora a project di rectory must be selected All input and output files as well as log files are stored here The file Z88ENVIRO DYN contains the path of this project directory Apart from that several other paths are stored here as well They permit for example the automated access to text viewers like Adobe Reader Furthermore some control flags for the configuration of the user interface are stored here e g a flag for the definition of the number of processors set by default Table 3 List of iO of file ZSSENVIRO DYN Purpose ss Possible Values Controls if mid nodes in case of Hexahedron No 10 with 20 nodes 0 Mid nodes not selectable NODEPICK and Tetrahedron No 16 with 10 1 Mid nodes selectable nodes can be selected 1 or not 0 Determines if at start of program all RANDSTART elements 0 or only surface ele ments 1 are displayed 0 All elements 1 Only surface elements LANG Defines the language and is alway
86. eme amount of memory because the element stiffness matrix has the order 60 60 The nodal numbering of the element No 10 must be done carefully and must exactly match the sketch below Pay attention to the location of the axis system The possible error message Jacobi determinant zero or negative is a hint for incorrect node num bering Pay attention to surface and pressure loads when using forces cf chapter 3 4 It 1s easier to enter these loads via the surface and pressure loads file Z88I5 TXT Hexahedron No 10 can be generated by the mesh generator Z88N from super elements Hexa hedron No 10 Thus the Hexahedron No 10 is well suited as super element Hexahedron No 10 can also generate 8 node Hexahedrons No 1 Input CAD see chapter 2 7 2 Upper plane 1 9 2 10 3 11 4 12 1 quit LINE function Lower plane 5 13 6 14 7 15 8 16 5 quit LINE function 1 17 5 quit LINE function 2 18 6 quit LINE function 3 19 7 quit LINE function 4 20 8 quit LINE function 7881 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt IOFLAG 1 if surface and pressure loads for this element are filed in Z8815 TXT gt 3 degrees of freedom for each node gt Element type is 10 gt 20 nodes per element 111 LIB or Theorie Manual gt Cross section parameter OPARA is 0 or any value has no influence gt Integration order INTORD for each mat info line 3 is usually good Z8813 TXT gt Integrat
87. en divided by the cur rent number of Gauss points This results in a mean value for the von Mises principle Tresca stress per element The value of the order of integration INTORD in the header file Z38MANAGE TXT is important and INTORD must be greater than 0 3 von Mises principle Tresca stresses directly in Gauss points This 1s most accurate but does not deliver as pretty pictures as 1 and 2 INTORD must be greater than 0 Z88 Aurora may show the following reduced stresses but only one at a time depending on the previous computation run Distortion Energy Theory DET 1 e von Mises stresses Principal stress hypothesis PSH 1 e Rankine stresses Shear stress hypothesis SH 1 e Tresca stresses Thus if you have computed the von Mises stresses previously Z88 Aurora will show them If you want to show the Rankine stresses now you have to run the solver again in this case with the setting Principal Stress Hypothesis SH Tresca see Figure 31 No calculation of reduced stresses Stress parameters von Mises stresses von Mises stresses v gt q Principal stresses Rakine Compute 2x2 x2 Gauss points v Tresca stresses amp Options No results RUN Figure 31 Setting options stress parameters in the menu Solver Plot of deflections You may plot the undeflected or the deflected structure or both of them overlaying The enlargement factor is adjustable with 100 as the default value for X Y and Z In a
88. enerator input file Z88NLTXT Example for the generation of a FE structure with 8 FE Plane Stress Elements No 7 from a super structure with 2 Plane Stress Elements No 7 looks the same with Toruses No 8 Figure 28 Specials The mesh generator checks which nodes are already known at the production of new FE nodes For this check it needs a trap radius a computer cannot meet a floating point number exactly This trap radius is provided for all 3 axes per default 0 01 Modify the trap radiuses when processing very small or very large numerical values 1 12 3 25 27 31 33 _37 Koinzidenz 1 Superelement 1 2 3 4 5 6 7 8 Koinzidenz 2 Superelement 4 3 9 10 7 11 12 13 Figure 29 Transformation of super elements into finite elements Attention mesh generator Z88N The generator can easily generate input files which blast all limits of the FE processor Generate therefore at first rougher FE structures check the re 93 LIB Theorie Manual sults then refine if necessary A good starting point Produce approx 5 10 times more finite elements than super elements Note mesh generator Z88N If the coordinate flag KFLAGSS is set in the mesh generator input files Z88NI TXT 1 e input values are polar or cylindrical coordinates then the mesh generator output files Z8811 TXT normally have Cartesian coordinates and KFLAG is set to 0 Ifyou set the coordinate flag output KFLAG to 1 however then the coordinates are polar or cylindrical in th
89. ent phase Please note that currently not all the functions are implemented therefore certain func tions cannot be selected and the modification of parameters in the user interface to some ex tent show no effect How Z88 deals with other programs and utilities etc is not predictable It is the aim of this research version to give you an understanding of the fundamental operating concept The de velopers of Z88 Aurora are interested in constantly improving this software Proposals sug gestions and remarks can be sent to aurorasupport z88 de In addition FAQs are available on the homepage www z88 de and users can exchange experiences in a forum The present version Z88 Aurora V 1 was tested on WINDOWS 7 32 and 64 bit WINDOWS Vista 32 and 64 bit and WINDOWS XP 32 and 64 bit Mah Aurora 126 Theory Manual 1 2 Summary of the Z88 element library TWODIMENSIONAL PROBLEMS PLANE STRESS PLATES BEAMS TRUSSES Plane Stress Triangle Element No 3 E Shape functions quadratic but linear Quality of displacements very good Quality of stresses in the centre of gravity good Computing effort average Size of element stiffness matrix 12 x 12 Plane Stress isoparametric Element No 7 Quadratic isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very well Quality of stresses in the corner nodes good Computing effort High Size of element stiffness
90. er z88ainp Generation gt of Z8811 TXT from an ABAQUS input file Generation gt of ZSS12 TXT from an ABAQUS input file Generation gt of ZSSI5 TXT from an ABAQUS input file Export functions of the converter z88aexp Generation gt of 288 inp from Z8811 TXT and Z8812 TXT How to proceed You can use files from ABAQUS CAE as well as your own input decks Please look for the corresponding keywords in the ABAQUS documentation and pay attention to upper and lower case characters ABAQUS scripts cannot be processed For the import of an ABAQUS file proceed as follows 81 Theorie Manual Ze 60 Aurora Importing and meshing the component in ABAQUS The ABAQUS converter only processes components which you can arbitrarily import into ABAQUS CAE and fit into an Assembly It is up to you whether you select Mesh on Part or Mesh on Instance Generate a material with elastic isotropic properties Edit Material X Name material 1 Description Material Behaviors General Mechanical Thermal Other Elasticity Plasticity Hyperelastic Damage for Ductile Metals HyperFoarn Damage For Traction Separation Laws Hypoelastic Damage for Fiber Reinforced Composites Porous Elastic T F T F TF By Damage For Elastomers Wiscoelastie Deformation Plasticity Damping Expansion Brittle Cracking Mesh Controls x Element Shape Technique Algorithm O Asis Medial axis O Free 4 Minimize the me
91. esian 0 or cylindrical coordinates 1 gt Set shell flag IHFLAG to 0 or I analogously to 2 or 3 in case of thin shells to 4 in case of very thin shells If IHFLAG is not 0 a surface load can be imported simplified into the material entries in Z8811 TXT via the Second moment of inertia RIYY Otherwise the Second moment of inertia RIYY is set to 0 gt surface and pressure loads flag IOFLAG 1 if entry of surface and pressure loads via Z8815 TXT gt 6 degrees of freedom for each node gt Element type is 23 gt 8 nodes per element gt Cross section parameter OPARA is the element thickness gt Integration order for each mat info line 3 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 136 Mah Aurora 56 Theory Manual 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 23 gt
92. esses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 108 Mah Aurora 126 Theory Manual Z8815 TXT This file is optional and only used if in addition to nodal forces edge loads applied onto element no 8 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Results Displacements in R and Z X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations It is SIGRR stress in R direction radial stress X direction SIGZZ stress in Z direction Y direction TAURZ shear stress in RZ plane XY plane SIGTE stress in peripherical direction tangential stress Optional von Mises stresses Nodal forces in R X and Z Y for each element and each node
93. etry data or super structures as well as to continue using existing FE data from Version 13 of the Open Source program Z88 Furthermore data can be exported in different formats Each of these converters offers an individual range of functions and its own setting options 1f necessary But since especially the actual proprietary data formats of simulation programs do not meet any national or international standard the respective producers can conduct changes in the files when issuing a new version which can influence the converters When using neutral formats for geometry or product data STL or STEP some appropriate adjustments might have to be made in the CAD programs in order to generate a functioning FE model in the de sired accuracy CAUTION In the following paragraphs the range of functions of the converters are listed as well as the programs with which they were tested In spite of intensive tests we cannot guar antee the compatibility of files from other programs or newer versions Please note the respec tive support in the explanations There are two possibilities to access the import and export functions of files 1 Via the text menu Figure 13 2 Via the toolbar Figure 14 si View Preprocessor Solver Postprocessor Hi N View Preprocessor Solver Postprocessor Help i New iNew coo ere xn E EEEE d L Open project d L Open project bal Save project as La Save project as Close project l Close project
94. ew The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Results Displacements in X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KFLAG 1 the radial stresses SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 119 LIB Theorie Manual 5 15 TORUS NO 15 WITH 6 NODES B This is a curvilinear Serendipity torus element with square shape functions The transforma tion is isoparametric The integration is carried out numerically according to Gauss Legen dre Thus the integration order can be selected in Z8811 TXT in the material information lines The order 7 is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surf
95. exactly Pay attention to edge loads when using forces cf chapter 3 4 It 1s easier to enter edge loads via the surface and pressure loads file Z8815 TXT You may combine this element with elements no 3 not recommended or ele ments no 14 good Plane Stress Elements No 7 can be generated by the mesh generator Z88N from super ele ments Plane Stress Elements No 7 or No 11 Thus the Plane Stress Element No 7 is well suited as super element Input CAD see chapter 2 7 2 1 5 2 6 3 7 4 8 1 7881 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt IOFLAG 1 if edge loads for this element are filed in ZSSI5 TXT gt 2 degrees of freedom for each node gt Element type is 7 gt 8 nodes per element gt Cross section parameter OPARA is the element thickness gt Integration order INTORD per each mat info line 3 is usually good 78813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG 0 Calculation of SIGXX SIGYY and TAUXY gt KFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD n
96. f stresses in the corner nodes good Computing effort Very high Size of element stiffness matrix 24 x 24 12 Hah Aurora 56 Theory Manual Torus No 15 Dz Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 12 x 12 Z Y R X Cam No 5 fs Linear function for torsion and tensile stress cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Low Size of element stiffness matrix 12 x 12 Us SHELL PROBLEMS Shell No 21 FR curvilinear isoparametric Serendipity volume shell element isoparametric transformation arbitrary curvature of element possible good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact Computing effort high Size of element stiffness matrix 48x48 13 Theorie Manual Shell No 22 FR curvilinear isoparametric Serendipity volume shell element isoparametric transformation arbitrary curvature of element possible good calculation of both displacements and stresses Stresses in the corner nodes good for an overview or in the Gauss points substantially more exact
97. fo line 3 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z88I1 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG has no influence gt Reduced stress flag ISFLAG 132 Zod Aurora 56 Theory Manual 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file 1s optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 21 gt Element number gt Pressure positive if pointing towards the surface gt Tangential shear positive in local r direction gt Tangential shear positive in local s direction gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises
98. for each node gt Element type is 11 gt 12 nodes per element gt Cross section parameter OPARA is the element thickness gt Integration order INTORD per each mat info line 3 is usually good 78813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG 0 Calculation of SIGXX SIGYY and TAUXY gt KFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 113 LIB or Theorie Manual 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces edge loads applied onto element no 11 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and 2 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 4 may differ from the local nodes 1 2 3 4 used for the coincidence Results Displacements i
99. h Aurora 126 Theory Manual gt X Plane stress element with surface loads Hexahedron No 1 Element number with surface and pressure load Long Pressure positive if pointing towards the surface Double Tangential shear positive in local r direction Double Tangential shear positive in local s direction Double 4 nodes of the loaded surface 4 x Long Example The hexahedron 356 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 99 and 12 The first surface load is pressure with 100 N mm The second surface load is applied tangentially and positive in local r direction with 200 N mm The third surface load is applied tangentially and positive in local s direction with 300 N mm Thus gt 356 100 200 300 51 34 99 12 Hexahedron No 10 Element number with surface and pressure load Long Pressure positive if pointing towards the surface Double Tangential shear positive in local r direction Double Tangential shear positive in local s direction Double S nodes of the loaded surface 8 x Double Example The hexahedron 456 features surface loads The load should be applied onto the surface defined by the corner nodes 51 34 99 and 12 and the mid nodes 102 151 166 and 191 The first surface load is pressure with 100 N mm The second surface load is applied tangentially and positive in local r direction with 200 N mm The third surface load is applied tangenti
100. h Z88G e Tetrahedron No 16 Tetrahedron parabolic in Pro ENGINEER e Tetrahedron No 17 Tetrahedron linear in Pro ENGINEER e Plane stress No 14 Shell triangle parabolic in Pro ENGINEER e Plane stress No 7 Shell quadrangle parabolic in Pro ENGINEER e Plate No 18 Shell triangle parabolic in Pro ENGINEER e Plate No 20 Shell quadrangle parabolic in Pro ENGINEER e Torus No 15 Shell triangle parabolic in Pro ENGINEER e Torus No 8 Shell quadrangle parabolic in Pro ENGINEER e Shell No 23 Shell quadrangle parabolic in Pro ENGINEER e Shell No 24 Shell triangle parabolic in Pro ENGINEER Please keep in mind that Z88G is capable to deal directly with pressure loads from Pro ENGINEER only with NASTRAN files In this case the file for surface and pressure loads Z88I5 TXT is generated This is not possible for COSMOS files Here you are to enter pressure loads via nodal forces How to proceed First step Choose NASTRAN or COSMOS file format If you choose NASTRAN the file Z88G NAS is loaded in case of COSMOS the file Z88G COS is loaded You must know which file type did you file in your former Pro E session Choose file type before start Next step Pro ENGINEER makes no distinction between volume elements plane stress ele ments shells torus elements and plate elements therefore it is up to you to feed Z88G the right information The reason for this is that Pro ENGINEER only recognises the FE type shell or vol
101. he geometry 1s visualised in Z88 Aurora and can be processed The same functionalities are available when you access the STEP import via the toolbar 61 PO a Mini Aurora Theorie Manual hy geometry file 2 4 Tem Desktop Beispiele test Recently Used amp Main C DVD RW Laufwerk D BD ROM Laufwerk F 2 DVD RW Laufwerk AR wie Add Bemove ascii stl tem Figure 19 Importing STL files 4 14 THE DXF CONVERTER IN AURORA Z88X What is the basic idea and which are the features 2D CAD systems like AutoCAD offer a simple possibility to transfer complex 2D or 2 D structures into Z88 Aurora without an expensive 3D system For this purpose the layer based structure of the DXF files is perfectly suited It is an interesting fact that the CAD converter Z88X works in both directions Which CAD systems can cooperate with Z88X Any CAD systems which can import read and export write DXF files However we can not guarantee any success Z88 V13 has been tested together with different AutoCAD and AutoCAD LT versions and AutoDesk s DXF guidelines have been regarded as the inventor of the DXF interface 1 e according to AC1009 and AC1012 Choose AutoCAD R12 DXF format if in doubt 62 a 56 Aurora Theory Manual DOA SB 000 tet tes R Mm y import lt menu import export gt geometry FE structure E STEP File Nastran File i a PP Ansys File
102. he true stresses resulting from plate bending moments and plate torsion moments Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 127 LIB or Theorie Manual 5 19 PLATE NO 19 WITH 16 NODES This is a curvilinear Lagrange Reissner Mindlin plate element with cubic shape functions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z8811 TXT in the material information lines The order 4 4 x 4 points is very good This element calculates both displacements and stresses very precisely The input amount is heavy you should use the mesher Z88N The integration order can be chosen again for the stress calculation The stresses are calcu lated in the corner nodes good for an overview or calculated in the Gauss points substan tially more exactly Area loads are defined in the appropriate material lines file Z28811 TXT instead of Second moment of inertia RIY Y For this element you need to set the plate flag IP FLAG to 1 Attention In contrary to the usual rules of the classic mechanics Z88 defines Ox the rotation around the X axis and 0 the rotation around the Y axis Mesh generation with ZSSN Use plates No 20 for super elements resulting in finite elements of type 19 plates No 20 may generated by AutoCAD or Pro ENGINEER ref the chapters of Z88X an
103. his element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology The converter functionality in Z88 Aurora offers the possibility to import and process files with this element type by means of Z88G For further information see chapter 4 1 8 a DXF data exchange with Z88X is not pos sible because this will make no sense Tetrahedron No 17 also applies well for thick plate elements 1f the plate s thickness 1s not too small compared to the other dimensions Basically this element calculates deflections and stresses very bad 1 e inaccurate One needs very fine meshes to obtain useful results Its one and only reason is the data exchange with 3D CAD systems Use tetrahedrons No 16 hexahedrons No 1 and best choice hexahedrons No 10 Tetrahedron No 17 cannot be generated by the mesh generator Z88N A DXF data exchange with Z88X is not implemented because tetrahedrons due to their strange geometry are very difficult to arrange in space This element s main purpose is the use with automeshers from third party suppliers Caution Sometimes the automeshers of CAD systems produce very bad element and nodal numbering resulting in an useless large amount of memory needs of Z88F In this case renumber especially the nodes X Input Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt IOFLAG 1 if pressure loads for this element are filed in Z8815 TXT g
104. in Z direction pointing down Node 19 1s fixed in X and Z and node 20 1s fixed in Y and Z Thus RBD I 1 2 2 O RBD 2 1 3 2 O RBD 3 2 120 RBD 4 2 3 2 O RBD 5 7 3 1 30000 RBD 6 8 3 1 30000 RBD 7 19 1 2 0 RBD 8 19 3 2 0 RBD 9 20 2 2 0 RBD 10 20 3 2 0 8th step if surface and pressure loads are defined create the layer Z88FLA and activate it Write with the TEXT function into a free space well into any place of your drawing 8 1 Number of surface and pressure loads 1 0 the first input group of the surface and pressure loads file Z88I5 TXT ZSSI5 TXT number of surface and pressure loads Write into one line separate each item by at least one blank Make sure to write in the layer Z88FLA Example The structure features 12 surface loads Thus Z88 5 TXT 12 8 2 Surface and pressure loads 74 Zod Aurora 126 Theory Manual 1 e the second input group of the surface and pressure loads file Z8815 TXT FLA number of the surface and pressure load The following entries depend on the element type with surface and pressure load gt Plain stress element No 7 and 14 and Torus elements No 8 and 15 Element number with surface load Pressure positive if pointing towards the edge Tangential shear positive in local r direction 3 nodes of the loaded edge Example The plain stress element 97 1s the third element with surface load The load should be applied onto the edge defined by the corner nodes 5 and 13 and by the mid node 51 One
105. ion around the Y axis This element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology In addition a mesh generation with ZSSN is possible Super elements of type 20 cannot only generate finite elements of type 20 but plates of type 19 with 16 nodes too Input CAD 5 2 6 3 7 4 8 1 ref chap 2 7 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to I or 2 if you want to reduce the shear influence gt set surface and pressure loads flag IOFLAG to O for your convenience Then the entry of the pressure is done via the Second moment of inertia RIYY see below If IQFLAG is set to 1 then the entry of the pressure is done via the surface and pressure loads file Z8815 TXT gt 3 degrees of freedom for each node w 0 0 gt Element type is 20 gt 8 nodes per element gt Cross section parameter OPARA is the element thickness gt Second moment of inertia RIYY is the area load gt Integration order INTORD per each mat info line 2 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 2 3 4 Calculation of the stresses in the Gauss points gt KFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of redu
106. ion order INTORD for stress calculation Can be different from INTORD in Z8811 TXT 0 Calculation of stresses in the corner nodes 1 2 3 4 Calculation of stresses in the Gauss points gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces surface and pressure loads applied onto element no 10 gt Element number with surface and pressure load gt Pressure positive if pointing towards the surface gt Tangential shear positive in local r direction gt Tangential shear positive in local s direction gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 2 3 4 may differ from the local nodes 1 2 3 4 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mises or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 112 Zod Aurora 126 Theory Manual 5 11 PL
107. le gt Import gt DXF files In the selection menu you can choose which of the following files are supposed to be created e a file of general structure data Z8811 TXT or e a complete Z88 data record with Z8811 TXT ZS8S12 TXT Z8813 TXT and ZS8I5 TXT if applicable e aZ8sIl TXT from a super structure which you can mesh manually in Aurora e aZSSI1 TXT from a super structure which is meshed with the information deposited in the DXF file for this purpose the ordered mesher Z88N is launched directly after wards The same functionalities are available when you access the Z88 import via the toolbar 64 Z66 Aurora 126 Theory Manual 4 1 6 FROM Z88 TO CAD SYSTEM In Z88 Input files Z88xx TXT You have produced the input files e Mesh generator file ZSSNI TXT or e File of the general structure data Z8811 TXT or e complete Z88 data set with Z8811 TXT Z88L TXT ZSSI3 TXT and Z8SI5 TXT if needed either by an editor a word processing program EXCEL or your own routine or by modifying data files that came from the CAD converter Z88X In Z88 Aurora Launching the CAD converter Z88X in the export mode Select in the menu File gt Export gt DXF files All data of the current project 1 e structure and boundary conditions are written in the file Z88X DXF If the input files contained polar or cylindrical coordinates they are converted into Cartesian coordinates In the CAD system Import the DXF file Z88X DXF Save the loaded drawing
108. led automeshers which divide a CAD model into finite elements This generated mesh can be stored in some output format to fit the needs of the various FEA programs Typical output formats are the COSMOS and the NASTRAN format for the COSMOS or the NASTRAN FEA program DOA SHEBA OOO CE kA 40 9 import lt geometry FE structure gt menu import export gt G STEP File f 4 Abaqus File Di DXF File Y d Ansys File 2 Cosmos File w Z88 File amp DVD RWeLaufwerk D B BD ROM Laufwerk F 9 DVD RWeLaufwerk 8 BD ROM Laufwerk F 2 DVD RW Lautwerk Figure 22 Accessing the 3D converters Z88G and import options in ZS amp Aurora Z88G is developed and tested for Pro ENGINEER by Parametric Technology USA Pro ENGINEER must include the option the additional module Pro MECHANICA Be sure to define the material data e g for steel only Young s Modulus and Poisson s Ratio is really needed in Pro ENGINEER Then you may activate FEM in the Pro ENGINEER program after designing your 3D model define a coordinate system which must be in harmony with Z88 and add forces and bound ary conditions to single points Create these single points with Feature gt Datum gt Point For plates the direct entry of the pressure load is allowed When using Wildfire 2 do not forget to define an analysis Otherwise no boundary conditions are filed Modify the mesh control values if necessary Cr
109. lement type is 4 gt 2 nodes per element gt Cross section parameter OPARA is the cross sectional area of the truss Z8813 TXT Trusses No 4 have no influence However Z8813 TXT must exist with any content Results Displacements in X Y and Z Stresses Normal stresses Nodal forces in X Y and Z for each element and each node 103 Ue Theorie Manual 5 5 CAM ELEMENT NO 5 WITH 2 NODES The cam element is a simplification of the general beam element No 2 It has always a circu lar cross cut The element lies concentrically to the X axis consequently local and global co ordinates have the same direction Inputs and calculations are simplified strongly through this Like with the beam element the results are exact according to Bernoulli s bend theory and Hooke s law and not approximate solutions like with the continuum elements X Uy Input CAD see chapter 2 7 2 Line from node 1 to node 2 7881 TXT gt Set KFLAG on 0 for Cartesian coordinates gt 6 degrees of freedom in a node Attention DOF5 not right hand rule see below gt Element type is 5 gt 2 nodes per element gt Cross section parameter OPARA is the diameter of the cam Z8813 TXT Cams No 2 have no influence However Z88I3 TXT must exist with any content Results Displacements in X Y and Z and rotations around X Y and Z Attention DOF5 not right hand rule see below Stresses SIGXX TAUXX Direct stress shear stress
110. les with an editor or word proc essor as usual These altered files have to be imported again for subsequent use in Z88 Aurora In case of word processor systems you have to pay attention to create pure ASCII texts which means without concealed control characters Every word processor program in cludes such an option The single Z88 V13 input files read Z8811 TXT general structure data coordinates coincidence material information Z8812 TXT boundary conditions and loads Z88I3 TXT control values for the stress processor Z8814 TXT control values for the sparse matrix solver Part 2 Z8812 Pardiso interface Z8SI5 TXT surface and pressure loads if needed or Z88NI TXT input file of the mesh generator Z88N Since further functionalities are projected in Z88 Aurora such as natural frequency calcula tion non linear material performance etc the existing Z88 file structures have been adjusted to the additional requirements There are now several definition files additionally not all in formation required for the calculation are used from the Z88I files The changes resulting from this are henceforth marked by a A The single Z88 Aurora input files read Z8811 TXT general structure data coordinates coincidence Z8812 TXT load cases boundary conditions and loads Z8SI5 TXT surface and pressure loads if needed ZSSMAT TXT material definition ZSSELP TXT element parameters ZSSMANAGE TXT control parameters for the stress
111. matrix 16 x 16 4 Y 1 X 2 Truss No 9 Br Linear function Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Minimal Size of element stiffness matrix 4 x 4 Y 2 LIB Theorie Manual Plane Stress Isoparametric Element No 11 ES Cubic isoparametric Serendipity element Quality of displacements excellent Quality of stresses in the Gauss points excellent Quality of stresses in the corner nodes good Computing effort Very high Size of element stiffness matrix 24 x 24 Beam No 13 Br Linear function for tensile stress cubic function for bending stress Quality of displacements exact Hooke s law Quality of stresses exact Hooke s law Computing effort Low Size of element stiffness matrix 8 x 8 YU Y algebraic sign X Plane Stress Isoparametric Element No 14 Z Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort medium gt Size of element stiffness matrix 12 x 12 10 Mah Aurora 126 Theory Manual Isoparametric Plate Element No 18 ai Quadratic Isoparametric Serendipity element following Reissner Mindlin s theory Quality of displacements very good Quality of stresses in the Gauss points good Quality of stresses in the corner node
112. ment You may not reverse engineer decompile or disassemble the Software Any transfer must include the most recent update and all prior versions The Software is for calculation Finite Element Structures there is no warranty for accuracy of the given results 4 Warranties LCAD gives no warrants the Software will perform substantially in accordance with the accompanying documentation Any implied warranties on the Software are not given S No liability for consequential damages In no event shall LCAD be liable for any other damages whatsoever including without limitation damages for loss of busi ness profits business interruption loss of business information or other pecuniary loss personal damage arising out of the use of or inability to use this Software product even if LCAD has been advised of the possibility of such damages 7 Governing Law This Agreement shall be governed exclusively by and be construed in accordance with the laws of Germany without giving effect to conflict of laws Z66 Aurora 126 Theory Manual WELCOMES TO Z865 AUTOTA asesitataitiisr eones dois 3 l THE FINITE ELEMENTS PROGRAM Z88 AUurora ccccccesssssscceeceeeeccceeeeeceesessssnaaeeeeeeeeeeeeeeeeeeeeeeeas 7 1 1 General overview of the FE program Z88 Aurora ooooooooooooooooonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnn nono nono non non nro nono no nnnnnnnnos 7 2 Summary ofthe Z88 element library certain orinar fcoorae iiini 9 Twodimensional pr
113. mesh generator mapped mesher in the menu Preprocessor reads the super structure data Z88NI TXT which again can be generated by a CAD system or compiled by hand and computes the general structure data Z8811 TXT 20 Plate Aurora 56 Theory Manual 2 3 Which Z88 Element types can be produced automatically Table 1 Automatically producible element types DXF element type function DXF hexahedron hexahedron No 1 finer f o o os fos Y Y Y hexahedron No 10_ quadrate x _x Y Y Y tetrahedron N tetrahedron No 16 guadratie Y Y Y Y x tetrahedron No 17 finer Y Y Y Y x plane stress plane stress No 3 quadratic so fos x x Y plane stress No 7 guadratie Y Y _x x Y o plane stress No 11 eubie s fos e s Y plane stress No 14 quadratic V Y _x __x Y o torus E torus No 6 linear e a Y torusNo 8 guadraie Y Y e x Y tors No 12 feubie os ooe x x Y torusNo 1S guadratie Y Y _x xx Y 8 plate quadratic Y OY x x Y plate No 19 fembie x x x x x Y plate No 20 quadraie Y Y __x x Y shell w shell No 21 quadraie s fos x o e Y shell No 22 quadratic s fos x x Y shell No 23 quadraie Y s x Y shell No 24 quadraie x Y o x Y i truss and beam structures with special case cam e mp trussNo 4 fea Ye Ye fo
114. mesh generator file no plates no area loads use default for trap radius Thus ZSSNI TXT 2 37774100000 12 Mah Aurora 56 Theory Manual 6 2 Material information lines For every material information one separate line MAT Number of the material information This material information starts with element no abc inclusively This material information ends with element no xyz inclusively Young s Modulus Poisson s Ratio Integration order from I to 4 Cross section value e g for plane stress elements thickness for trusses cross section area And if beams but not plates are defined in addition Second moment of inertia yy bending around yy axis Max distance from neutral axis yy Second moment of inertia zz bending around zz axis Max distance from neutral axis zz Second moment of area torsion Second modulus torsion And if plates or shells but not beams are defined in addition area load Write into one line separate each item by at least one blank Make sure to write in the layer Z88GEN Example The structure has 34 super elements type 7 with varying thickness Elements 1 to 11 have thickness 10 mm elements 12 to 28 have 15 mm and elements 29 to 34 have 18 mm Material steel Integration order shall be 2 MAT 1 1 11 206000 0 3 2 10 MAT 212 28 206000 0 3 2 15 MAT 3 29 34 206000 0 3 2 18 6 3 Stress parameters The input line of the stress parameter file Z8813 TXT Z8SI3 TXT Integra
115. more exactly than the curvilinear triangle plates No 18 you should prefer always plates No 20 Input CAD 4 2 5 3 6 1 ref Chap 2 7 2 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt set plate flag IPFLAG to I or 2 if you want to reduce the shear influence gt set surface and pressure loads flag IOFLAG to O for your convenience Then the entry of the pressure is done via the Second moment of inertia RIYY see below If IQFLAG is set to 1 then the entry of the pressure is done via the surface and pressure loads file ZSSI5 TXT gt 3 degrees of freedom for each node w 0 gt Element type is 18 gt 6 nodes per element gt Cross section parameter OPARA is the element thickness gt Second moment of inertia RIYY is the pressure load gt Integration order INTORD per each mat info line 3 is usually good Possible is 3 for 126 Hah Aurora 56 Theory Manual 3 Gauss points 7 for 7 Gauss points and 13 for 13 Gauss points For easy use with plate element No 20 e g with Pro ENGINEER function SPLASS of Z88 uses internally these values integration order 1 or 2 in Z8811 TXT 3 Gauss points integration order 4 in Z8811 TXT 7 Gauss points Example Z8811 TXT uses an entry of 2 for INTORD Thus plate elements No 20 use 2x2 4 Gauss points and plate elements No 18 use 3 Gauss points for integration Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the
116. n FEA programs is truly of philosophi cal character As a matter of fact numerous experiments and computer studies at the Institute of Engineering Design and CAD of the University of Bayreuth Germany showed that some very expensive and well known professional FEA programs produced incorrect stress plots in some situations The best way 1s the computation of stresses directly in the Gauss points However this is odd for OpenGL in some modes so I decided for the following way after a lot of experiments 95 LIB Theorie Manual l von Mises principle Tresca stresses in corner nodes In fact the stresses are computed not really in the corner nodes which would lead to very wrong results especially for very tapered elements sic but in Gauss points lying near the current corner nodes Stresses are computed for just the same number of Gauss points like the number of corner points Because often a node is linked to more than one element the stresses are computed to a mean value from the corner node stresses of all linked elements This results in pretty balanced stress shadings which are mostly somewhat lower than the maximum stresses in the Gauss points however The value of the order of integration INTORD in the header file Z88MANAGE TXT has no meaning but INTORD should be greater than 0 2 von Mises principle Tresca stresses as a mean value for each element The stresses are computed in the Gauss points of the current element added and th
117. n X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KFLAG 1 the radial stresses SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 114 Zod Aurora 56 Theory Manual 512 TORUS NO 12 WITH 12 NODES D This is a curvilinear Serendipity torus element with cubic shape functions The transformation is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Thus the integration order can be selected in Z8811 TXT in the material informa tion lines The order 3 is mostly sufficient This element calculates both displacements and stresses with outstanding precision The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calcu lated in the Gauss points substantially more exactly Because of 1ts 24 24 element stiffness matrices the element No 11 needs a lot of memory and computing power Pay attention to edge loads when using forces cf chapter 3 4 It 1s easier to enter edge loads via the surface and pressure loads file Z88I5 TXT
118. n Z88 gt CAD Completing FE structure in CAD e g with not mesh generator capable elements Conversion CAD gt Z88 Change e g material information in Z88 Conversion Z88 gt CAD Installation of the boundary conditions in CAD Conversion CAD gt Z88 FE analysis in Z88 Etc How to proceed 4 1 5 FROM CAD SYSTEM TO Z88 In the CAD system Remark This point case 1 1 will be explained in greater detail in chapter 4 1 7 This is a summary 1 Design your component Order and layers as you like 2 Define the FEA structure or the super structure by lines and points Any order and layers therefore unproblematic and fast 3 Number the nodes with the TEXT function on the layer Z88KNR Any order therefore un problematic and fast 4 Write the element information with the TEXT function on the layer Z88EIO Any order therefore unproblematic and fast 5 Outline each element with the LINE function on the layer Z88NET The only section with firm work rules and orders because of the topological information 6 Write general information material information and control information for the stress proc essor Z88D on the Layer Z88GEN 7 Define the boundary conditions on the layer Z88RBD 8 Define the surface and pressure loads if needed on the layer Z88FLA 9 Export or store your 3 D model or 2 D drawing under the name Z88X DXF In Z88 Aurora Launching the CAD converter Z88X Select in the menu Fi
119. nd 3 is sup posed to be fixed for the node 5 Resulting in 6 boundary conditions gt Thus 610000 load case_l 1 120 1220 1320 3 2 1 1648 5220 5320 34 Zod Aurora 56 Theory Manual For edge loads and surface loads pay attention to It is a good idea to define surface and pressure loads in the file ZSSI5 TXT However for plates no 18 no 19 and no 20 you may define the surface load directly in the material infor mation lines file ZSSI1 TXT in Z88V13 or ZSSELP TXT in Z88 Aurora Only forces and constraints should entered here into Z8812 TXT Of course it is possible too to convert surface loads into concentrated forces manually and to write these forces into Z8812 TXT which is the classical way but somewhat cumbersome For the elements with linear shape function e g Hexahedrons No 1 and Torus No 6 edge loads and surface loads are distributed to the elements simply and straight onto the respective nodes However for elements with higher shape functions 1 e square Plane Stress No 3 No 7 To rus No 8 Hexahedron No 10 or cubic Plane Stress No 11 and Torus No 12 edge and sur face loads have to be put onto the elements according to fixed rules which are not always physically obvious Amazingly some load components can have negative values Though these facts are not obvious nevertheless they lead to correct results which 1s not the case for intuitive distribution of loads to the respective nodes An ex
120. neutral axis yy Double 6th number Second moment of inertia zz bending around zz axis Double 7th number Max distance from neutral axis zz Double Sth number Second moment of area torsion Double 9th number Second modulus torsion Double 3 1 8 A SOLVER DEFINITION FILE ZSSMANAGE TXT The solver definition file Z383MANAGE TXT contains a lot of information which used to be available in different files Z88I3 TXT and Z8814 TXT It is divided into three parts the global part the linear solver part and the stress part The following figure shows a typical Z88MANAGE TXT DYNAMIC START GLOBAL GLOBAL START SIMCASE 1 NEG 1 IQFLAG 1 LOADCASE 1 LOADSELECT 0 LOADADD 0 GLOBAL END LINEAR SOLVER SOLVER START ICFLAG 3 MFLAG 0 MAXIT 10000 EPS Le 007 RALPHA 0 0001 ROMEGA 1 1 44 Zod Aurora 56 Theory Manual ICORE 4 OUTPATH Aout of corel DUMPMAX 1000 SOLVER END STRESS STRESS START NINTO 5 KSFLAG 0 ISFLAG l STRESS END DYNAMIC END Explanations to the single specifications GLOBAL NEG is the number of material laws IQFLAG is the surface load flag LINEAR SOLVER ICFLAG determines the solver type 0 Cholesky 1 SICCG 2 SORCG 3 Pardiso MAXIT is the first termination criterion When reaching this number of iterations the itera tion solvers SICCG and analogously SORCG are terminated in any case The values of the solution vector reached up to this point are printed however EPS This value is c
121. o 3 7 8 11 12 14 and 15 e Calculation of von Mises stresses for continuum elements No 1 3 6 7 10 11 12 14 15 24 4 2 3 SOME NOTES ON NODAL FORCE CALCULATION The results are presented in Z8804 TXT The nodal forces are calculated separately for each element If several elements meet a node one gets the complete nodal force for this node by adding the nodal forces of all accessing elements These results are presented further down in the nodal force file Z8804 TXT 4 2 4 THE CUTHILL MCKEE PROGRAMM Z88H The choice of nodal numbers is extremely important for the compilation of the stiffness ma trix Bad nodal numbering may result in huge memory needs which are not really necessary However Z88H may reduce the memory needs for the direct Cholesky Solver Z88F greatly the sparse matrix solvers Z88I1 Z88I2 and Z88I1 Z88PAR may also gain some advantages from a Z88H run but the iteration solver is a priori very stable regarding node numbering be cause of storing the non zero elements only Basically it is always good to achieve a small difference of nodal numbers for each finite element This results in nodal numbers of similar size for an element However this is not al ways possible consider a circular structure starting with nodal numbering at 0 with increas ing numbers clockwise When reaching 360 elements with large differences of nodal num 89 LIB Theorie Manual bers will occur 3D CAD programs sometimes c
122. oblems Plane stress plates beams trusS S coocccccccnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnninnnnss 9 Axisymmetric PIOD EIMOS ooooocoonononononononnnnnnnnnnnononnnnnnnnnnonnnononononononononononnnnn nono nn nro nn ssns sns nn nro nn nn n eseese senen 12 SUCIOS ri 13 Spano e 0 0 ee nO ita ES 2 THE Z88 COMPUTING UNITS ccccccsssssecceeeeeseessseeeeeeeeseessseeeeeeeeeseessaeeeeeeeesessseeeeeeeeseesaaeeeeees 18 IA nn ee eee ne ee 18 2 2 Short Deserprion ot the Modules seriinin n an E R AR EEN ERAAN 18 I The Pre and Postprocessor Be on PO EC o E ase A 18 II The Solver EH iia 18 STP DXF STL y III The interface modules to CAD and FEA systems a 2 Eg E es A APAA 19 IV The mesh generator for ordered meshes EEEE Pe o POE T 20 2 3 Which Z88 Element types can be produced automatically L oooooooocccocococonanoaooonononoonn nono nonnnnnononononnnonononos 21 3 THE INPUT AND OUTPUT OF Z88 AURORA cccccccccnnnnnnnnononononnnnnnnnnnccnnnnnnnnnnn nono nonnnnnnnnnncncnnnananannns 22 3l Creating input files AA RR OU U0P ePPP Pa 24 3 1 1 GENERAL STRUCTURE DATA Z8811 TXT neoinsiniii irradia 25 3 1 2 MESH GENERATOR INPUT FILE Z88NILTXT oooooooccnnnncnccccnnananononononcnnnnnnnncccnnnnnnnannnnnnnnnnnnoos 29 3 1 3 BOUNDARY CONDITIONS FILE Z8812 TXT cooooooonnnnnnnnccnnnonannnnnnnnnnnnnnnnncncccnnnnnnnnnnnonnnnnnnnos 34 3 1 4 STRESS PARAMETER FILE Z88I3 TXT cooocccccnnnnnononononononnnnnnonocononnnnnnnononnnnnnnnnnnnnncnncnnnnnnnnnns
123. often used for Rapid Pro totyping and mould flow simulations In addition there are also systems in the area of Re verse Engineering which can generate STL data from a 3D capture This means that compo nents can also be simulated without using a CAD model In contrast to STEP which can describe the surface of the component very accurately by means of B zier curves or splines STL is always a discretisation of the component 1 e all surfaces are divided into linearly edged triangles Therefore a loss of accuracy occurs espe cially at roundings or holes However this occurs in the FEA anyway however after the meshing at the latest But you should take into account that a poorly generated STL leads to an even more extensive loss of quality in the meshing process Therefore you should check the following settings when generating STL data if your source system offers this possibility 1 Angle control If you can define the minimum angle in a surface triangle in your CAD system it is recommended to permit angles with at least 30 Very acute angles de pending on the mesher in most cases lead to acute angles in the elements of the FE mesh which inevitably either generates elements which cannot be calculated too small or negative Jacobian Determinant or create bad results 2 Chord length A very small chord length also leads to triangles as equilateral as possi ble and to especially small triangles for the surface plot You should
124. ollowing formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point 1 input group Ist number Number of surface and pressure loads Long 2nd number No of load case 2 input group Surface and pressure loads one line per load Of course an element may have more than one load applied The following entries depend from the element type with surface and pressure load to avoid unnecessary data entries As for the local directions Define the the local r and s directions by the nodes and their se quence These local directions for the surface loads may differ from the local r and s coordi nate system of the finite element The numbering has to conform to the element numbering see chap 5 Plain stress element No 7 and 14 and Torus elements No 8 and 15 Element number with surface load Long Pressure positive if pointing towards the edge Double Tangential shear positive in local r direction Double 3 nodes of the loaded edge 3 x Double Example The plain stress element 97 image 11 7 1 features surface load The load should be applied onto the edge defined by the corner nodes 5 and 13 and by the mid node 51 One surface load is applied normally to the edge with 100 N mm and the other surface load is ap plied tangentially and positive in local r direction with 300 N mm defined by the two corner nodes Thus gt 97 100 300 5 13 SI 38 Ma
125. olver parameters of the four integrated solver types 3 1 9 OUTPUT FILES Z8800 TXT TO Z8808 TXT The following list is an overview of the Z88 Aurora output files Z8800 TXT prepared input data Z8801 TXT prepared boundary conditions ZS8O2 TXT calculated displacements ZSSO3 TXT calculated stresses ZS8O4 TXT calculated nodal forces The files Z8805 TXT and Z8808 TXT are no regular Z88 output files They are internally used for the preprocessor and stored as ASCII files so that experienced users can use them for their own routines if necessary 3 1 10 DEFINITION FILE Z88 DYN General settings such as memory needs or the appearance of Z88 Aurora are defined in the two definition files Z88 DYN and Z88ENVIRO DYN The user can influence their control 47 LIB Theorie Manual via the option menu under Help gt Options For further information about the settings in the option menu see the Z88 Aurora User Manual The files are located in the working directory of Z88 Aurora which 1s depending on the plat form in z88aurorav1 bin Selection operating system The working directory must not be confused with the project directory which is selected or defined independently by the user when starting the program Purpose and structure of the definition file Z88 DYN At the start of the program Z88 Aurora requests a defined amount of memory which can be controlled via the file Z88 DYN Apart from
126. om node 1 to node 2 Z 69 Theorie Manual Element No 3 14 15 18 and 24 1 4 2 5 3 6 1 Y Element No 6 1 2 3 1 Z Y 2 R X Element No 19 1 2 3 4 5 6 71 8 9 10 11 12 15 14 15 16 1 YN 10 TN 4 LY j ri J 70 10 io Sa Z S fe A 1 2 O14 18 Zod Aurora 56 Theory Manual Element No 1 Upper plane 1 2 3 4 1 quit LINE function Lower plane 5 6 7 8 5 quit LINE function 1 5 quit LINE function 2 6 quit LINE function 3 7 quit LINE function 4 8 quit LINE function Element No 10 Upper plane 1 9 2 10 3 11 4 12 1 quit LINE function Lower plane 5 13 6 14 7 15 8 16 5 quit LINE function 1 17 5 quit LINE function 2 18 6 quit LINE function 3 19 7 quit LINE function 4 20 8 quit LINE function Element No 21 Upper plane 1 5 2 6 3 7 4 8 1 quit LINE function Lower plane 9 13 10 14 11 15 12 16 09 quit LINE function 1 9 quit LINE function 2 10 quit LINE function 3 11 quit LINE function 4 12 quit LINE function Element No 22 Upper plane 1 4 2 5 3 6 1 quit LINE function Lower plane 7 10 8 11 9 12 7 quit LINE function 1 7 quit LINE function 2 8 quit LINE function 3 9 quit LINE function 71 LIB Theorie Manual 6th step Define the layer Z88GEN and switch it active Write with the TEXT function into a free space well into any place of
127. ompared to a norm of the residual vector When this value is reached for the iteration solvers SICCG and SORCG the solution reached should have a good precision This is the second termination criterion Enter a relatively small value e g 0 00001 or 0 0000001 Note that there is no absolute truth in this field No matter which norm of the re sidual vector is compared against this limit you can never be sure that all elements of the solution vector are precise The choice of EPS influences the iteration count and thus the computing speed enormously Remember this when comparing Z88 Aurora to the big com mercial solvers you do not know which termination criterions are internally used anyway The limit you can adjust there may have absolutely nothing to do with EPS of Z88 However extensive tests proved that the deflections of different nodes compared quite well to those from the commercial solvers if EPS was between 0 00001 and 0 0000001 with similar com puting time Please note When computing large FEA structures with different solvers you will never which solver delivers the best result anyway 45 LIB Theorie Manual RALPHA is the convergence acceleration parameter a With this parameter for the SIC pre conditioner you choose the shift factor a for the iteration solver SICCG from 0 to 1 good values may vary from 0 0001 to 0 1 0 0001 is a good initial value ROMEGA is the convergence acceleration parameter With this parameter fo
128. on line Cartesian coordinates no beams anyway 29 LIB Theorie Manual forbidden in the mesh generator file no plates no surface loads trap radius default value gt Thus 2 37774100000 KFLAG Internally Z88N works with natural or Cartesian coordinates Sometimes though you might want to enter the output of Z88N as polar or analogously cylindrical coordinates into the out put file Z8811 TXT With this flag 1 the output takes place in polar or analogously cylin drical coordinates This is independent from the flag KFLAGSS for the input file Z88NI TXT 2 input group Starting in line 2 contains coordinates of nodes one line per node node numbers strictly as cending Ist number Node number Long 2nd number Number of the degrees of freedom for this node Long 3rd number X coordinate or if KFLAG is 1 R coordinate Double 4th number Y coordinate or if KFLAG is 1 PHI coordinate Double Sth number Z coordinate or if KFLAG is 1 Z coordinate Double The Z coordinate can be skipped at 2 dimensional structures Example The node no 8 has 3 degrees of freedom and the coordinates X 112 45 Y 0 Z 56 75 gt Thus 8 3 112 45 0 56 75 ac input group Starting after last node contains coincidence 1 e the allocation of the element type and the corresponding nodes of every element Edit two lines for every super element The element numbers like the node numbers must be entered strictly ascending
129. ontain so called automeshers which divide the 3d model into finite elements This generated mesh can be stored in some output format to fit the needs of the various FEA programs But many of these automeshers generate meshes with very large nodal differences This is true for Pro ENGINEER s Pro MECHANICA If you choose Tet Mesh parabolic Pro MECHANICA in a first operation generates linear tetrahedrons 1 e with 4 rather than 10 nodes per element with straight element edges Then midnodes are put on the element edges resulting in parabolic elements with 10 nodes These midnodes inevitably have relatively large nodal numbers because the corner nodes were numbered in the first step Thus every finite element features relatively small corner node numbers and relatively large mid node numbers When choosing Shell triangle parabolic the same situation occurs This means that meshes built with Pro MECHANICA will always have a large difference of nodal numbering For large meshes one needs to re number the nodes to get finite elements with small differ ences of nodal numbers Several proper procedures do exist in literature for this task How ever the so called Cuthill McKee procedure is a good compromise which is based on graph theoretical considerations One modification of it is the RCMK algorithm reverse Cuthill McKee algorithm For more information consult Schwarz H R Die Methode der finiten Elemente The C program Z88H is based on a FORTRA
130. or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 133 LIB or Theorie Manual 5 22 SHELL NO 22 WITH 12 NODES FR This 1s a curvilinear Serendipity volume shell element The transformation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre The ele ment can be arbitrarily curved it is actually a kind of pie segment with square shape functions on the surface and linear shape functions in the thickness direction The integration order can be selected in Z88I1 TXT in the material information lines The order 3 i e 3x3 Gauss Points is mostly sufficient This element calculates both displacements and stresses very ex actly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points sub stantially more exactly The three degrees of freedom are the global displacements in X Y and Z There are no rota tional degrees of freedom since it is a volume element Input CAD upper plane 1 4 2 5 3 6 1 lower plane 7 10 8 11 9 12 7 Lines 1 7 2 8 3 9 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt surface and pressure loads flag IOFLAG 1 if entry of surface and pressure loads via Z8815 TXT gt 3 degrees of freedom for each node gt Element type is 22 gt 12 nodes per element gt
131. osed to be applied to elements No 21 gt Element number gt Pressure positive if pointing towards the surface gt Tangential shear in local r direction gt Tangential shear in local s direction gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 the local s direction is defined by the nodes 1 4 The local nodes 1 to 8 for the surface load may differ from the local nodes 1 to 8 used for the coincidence Shell No 21 with pressure load 40 Zod Aurora 56 Theory Manual Shell No 22 This file is optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 22 gt Element number gt Pressure positive if pointing towards the surface gt 3 corner nodes and 3 mid nodes of the loaded surface Mathematically positive in plain view Y Shell No 22 with pressure load Shell No 23 This file is optional and is only used if in addition to nodal forces surface and pressure loads are supposed to be applied to elements No 23 gt Element number gt Pressure positive if pointing towards the surface gt 4 corner nodes and 4 mid nodes of the loaded surface Mathematically positive in plain view 33 Shell No 23 with pressure load 41 LIB Theorie Manual Shell No 24 This file is optional and is only used if in addition to nodal forces surf
132. ot 0 3 Teresa stresses computed for the Gauss points INTORD not 0 Z8815 TXT 106 Z66 Aurora 86 Theory Manual This file is optional and only used if in addition to nodal forces edge loads applied onto element no 7 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in plain view The local r direction is defined by the nodes 1 2 The local nodes 1 2 3 may differ from the local nodes 1 2 3 used for the coincidence Results Displacements in X and Y Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations For KFLAG 1 the radial stresses SIGRR the tangential stresses SIGTT and the accompanying shear stresses SIGRT are computed additionally makes only sense if a rotational symmetric structure is available For easier orientation the respective radiuses and angles of the nodes points are printed Optional von Mises or principal or Tresca stresses Nodal forces in X and Y for each element and each node 107 LIB or Theorie Manual 5 TORUS NO 8 WITH 8 NODES B This is a curvilinear Serendipity torus element with square shape functions The transforma tion is isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Thus the in
133. ou should make a mistake at the outlining of an ele ment then delete all previous lines of this element e g with an UNDO function and start again at the first point of the element in question But 1f you notice now just outlining element 17 that you have made a mistake at element 9 then you must delete all lines of the elements 9 to 17 and restart with element 9 67 Zh Theorie Manual For your comfort you must keep the following outline orders which partly differ from the orders shown at the element descriptions when entering the coincidence by hand Z88X then sorts internally correctly Example The coincidence for the element type 7 is as follows in the element description First the corner nodes then the middle nodes reads 1 2 3 4 5 6 7 8 The coincidence list must look like this in the Z88 input files However for Z88X use for comfortably outlining the elements the order is 1 5 2 6 3 7 4 8 1 left picture respectively A B C D E F G H A right picture 4 7 3 G F E i r i q 5 2 A B C Figure 21 Example for correct outline orders Following the CAD outline orders for all elements except No 16 and No 17 because these tetrahedrons can only be machine generated nearly impossible by hand Element No 7 No 20 and No 23 1 5 2 6 3 7 4 8 1 3 4 Y 1 x 2 Element No 8 1 5 2 6 3 7 4 8 1 68 Zod Aurora 56 Theory Manual Element No 11 1 5 6 2 7 8 3 9 10 4 11 12 1 3 Element No 2 4 5 9 13 Line fr
134. plane SIGTE stress in peripherical direction tangential stress Optional von Mises or principal or Tresca stresses Nodal forces in R X and Z Y for each element and each node 121 Ue Theorie Manual 5 16 TETRAHEDRON NO 16 WITH 10 NODES amp This 1s a curvilinear Serendipity volume element with square shape functions The transfor mation 1s isoparametric The integration is carried out numerically according to Gauss Leg endre Thus the integration order can be selected in Z8811 TXT in the material information lines The order 4 1s good The quality of the displacement and stress calculations are far bet ter than the results of the tetrahedron element No 17 but less precise than hexahedron No 10 This element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology The converter functionality in Z88 Aurora offers the possibility to import and process files with this element type by means of ZS8G For further information see chapter 4 1 8 a DXF data exchange with Z88X is not pos sible because this will make no sense Tetrahedron No 16 also applies well for thick plate elements if the plate s thickness is not too small compared to the other dimensions The element causes a big computing load and needs a large amount of memory because the element stiffness matrix has the order 30x30 Pay attention to pressure loads when using forces cf chapter 3 4 It
135. put group in one line a csv file which contains the material data 1s accessed from this file The structure is very similar to that of the last input group in Z8811 TXT 1 input group Ist number Number of materials 2 input eroup one line for each material Ist number Material starts with element no inclusively 2nd number Material ends with element no inclusively 3rd number Integration order 4th number Material is allocated to solid No Sth number MATFLAG 0 Hooke s material further entry into 1 input group Name of csv file Explanation MATFLAG No options yet in Z88 Aurora 1 0 standard value 0 means Hooke s material performance In future Z88 Aurora versions non linear material performance is planned For this the new MATFLAG 1s required 43 Us Theorie Manual 3 1 7 A ELEMENT PARAMETER FILE Z88ELP TXT Contains the plate shell and beam information known from the last input group of the Z8811 TXT For this file the same applies as for Z88MAT TXT When importing an existing Z88 file the required data are transferred automatically later editing of the Z8811 TXT how ever does not influence the result 1 input group Ist number Number of Element parameters ls input group one line for each used element Ist number Element starts with 2nd number Element ends with 3rd number OPARA for beams 4th number Second moment of inertia yy bending around yy axis Double Sth number Max distance from
136. r the SOR pre conditioner you choose the relaxation factor for the iteration solver SORCG from 0 to 2 good values may vary from 0 8 to 1 2 Which value to choose for Good question Try with 1 which will never lead to totally bad results and then try other values for further runs with this structure ICORE is a control parameter of the Pardiso solver It determines the number of CPUs on multi core computers Allowed maximum is 9 OCCFLAG is the Out of Core variable of the Pardiso solver OUTPATH is a control parameter of the Pardiso solver It determines the swapping direc tory DUMPMAX is the given maximum memory used by the Pardiso solver Example 1 You want to use the Iterations Sparsematrix Solver and stop after 5000 iterations the limit is 0 0000001 and the convergence acceleration parameter w for SOR is 0 9 since you want to use the SORCG Solver SORCG sparse iterativ gt Thus MAXIT5000 EPS 0 0000001 RALPHA Standard value without significance ROMEGA 0 9 Example 2 You want to use the Iteration Sparse Matrix Solver and you want to stop positively after 10000 iterations the limit shall be 10 and the convergence acceleration factor a for SIC shall be 0 001 because you want to use the SICCG Solver SICCG sparse iterative gt Thus MAXIT10000 EPS le 9 RALPHA 0 001 ROMEGA Standard value without significance Example 3 You want to use the direct Sparse Matrix Solver with fill in Pardiso
137. rawing only some outline curves In contrast FEA sys tem have to render every finite element 1 e compute the normal vectors for any element sur face compute light effects for every tetrahedron etc Hidden line scenes put very heavy load on the CPU This can be solved by applying Surface Solid View which can be found in the view menu Here only the outer solid edges are calculated and completely displayed but this procedure is not suitable for all functionalities Z8815 TXT no yes for displaying the surface and yes for displaying the surface pressure loads and pressure loads O What can I plot with Z880 Nearly everything if a solver was run which stored the deflec tion file Z28802 TXT and the three stress files Z8803 TXT for you to check the stresses Z8805 TXT for Z880 internally and Z8808 TXT for Z88 Aurora internally Even for trusses you may plot the von Mises stresses 1 e tensile stresses with different colours only beams No 2 and No 13 and cams No 5 allow only the plotting of deflections and nothing more Why Because you must compute for beams and cams also the stress concentration fac tor which 1s impossible for a FEA system which deals with a whole structure of beams Of course you may compute the stresses in a chamfer by putting an FE mesh around it But this needs either plane stress elements or 3D elements but neither beam elements nor cam ele ments Plot of stresses The kind of plotting the stresses withi
138. rdinates de termines the nodal numbers and the element numbers of the FE structure Definition e Local x axis points in direction of local nodes 1 and 2 e Local y axis points in direction of local nodes 1 and 4 e Local z axis points in direction of local nodes 1 and 5 Super structures in space are subdivided first in z then in y and finally in x direction 1 e the FE element numbers start along the z direction To plane and axially symmetric structures ap plies analogously The numbering starts along the y axis or for axially symmetric elements along the z axis cylinder coordinates Along the local axes a subdivision can be conducted as follows e equidistant e increasing geometrically from node 1 to 4 or 5 mesh becomes rougher e decreasing geometrically from node 1 to 4 or 5 mesh becomes finer It 1s obvious that for lines or areas which are shared by two super elements the super ele ments must be subdivided exactly the same The mesh generator does not check this and then generates useless or totally meaningless FE meshes Example 92 Z66 Aurora 126 Theory Manual wrong local y right local y equal division different Figure 28 Subdivision of the super elements Since the local axes x y and z are defined by the location of the local nodes 1 4 and 5 it is possible to generate almost arbitrary numberings for nodes and elements of the FE structure by corresponding construction of the coincidence list in the mesh g
139. roup 6 is required if NIFLAG was set to 1 1 e the trap radiuses is supposed to be modified 1 line Ist number Trap radius in global X direction EPSX Double 2 number Trap radius in global Y direction EPSY Double 3rd number Trap radius in global Z direction EPSZ Double Skip the Z detail for 2 dimensionalen structures Example The trap radiuses shall be set to 0 0000003 for X Y and Z respectively gt Thus 0 0000003 0 0000003 0 0000003 This is effective only if NIFLAG was set to 1 in the first input group amp 7 input group optionally after the end of input group 6 Input group 7 is required if KFLAG is supposed to be set to 1 1 e an output in polar or cy lindrical coordinates 1s supposed to take place otherwise 0 for Cartesian coordinates 32 Plate Aurora v s Theory Manual Types 7 8 Types 11 12 local y direction local y direction local x direction Types 1 10 local y direction local x direction for overview reasons nodes 9 20 from typ 10 are oo not shown local z direction Figure 2 Definition of local x y and z direction using the example of different element types 33 L8G Theorie Manual 3 1 3 BOUNDARY CONDITIONS FILE Z8812 TXT In the file Z88I2 TXT the boundary conditions displacements and forces affecting the model are deposited Surface loads are found in the file Z88I5 TXT In Z88 Aurora it will be possi ble in the future to calculate differen
140. ructure of Hexahedrons No 10 and Beams No 2 is supposed to have 10 elements The coordinates are entered in Cartesian coordinates 3 material info lines 270 degrees of freedom and 45 nodes gt Thus 3 45 10 270 30 10 0 IPFLAG If Plates No 18 No 19 or No 20 appear in the structure then set plate flag IPFLAG to 1 oth erwise it must be 0 Example A two dimensional structure of Plates No 20 is supposed to have 100 ele ments The coordinates are entered in cylindrical coordinates 2 material info lines 340 degrees of freedom and 180 nodes The pressure on plates is found in the material laws i e IQFLAG 0 gt Thus 2 180 100 540 2 1 0 1 0 Caution This Z88 release allows only beams or plates in a structure not both in the same structure because the DOF of the beams and the plates are not compatible IQFLAG This flag controls if the surface and pressure loads file Z88I5 TXT is read 1 or not 0 The boundary conditions file Z8812 TXT features constraints defections and nodal forces Surface and pressure loads may be defined in Z8815 TXT if needed 25 LIB _Theorie Manual A In Z88 Aurora generated files the IQFLAG is contained in the file Z88MANAGE TXT The following plane elements can deal with surface loads plane stress elements No 7 11 and 14 torus elements No 8 12 and 15 The following plane elements can deal with surface and pressure loads hexahedrons No 1 and 10 and tetrahedrons No 16 and 17 shells 21
141. s 1 German compliant with Z88 DYN 2 English Default value for the number of computing kernels used in the cal PE E A CPU culation This is the number found pee k in the solver under extended set 9 A i tings OCC_MEM ee ee or aOR Ine OF re 2000 solver Pardiso OCC PATH Se for swapping of solver Pard e g DAOOC TOOLBAR_IMP Shows additional toolbar Import pogo 1 shown beaten iti JADE 0 hidden BAR VIEW Shows additional toolbar View TOOLBAR PRE Shows additional toolbar Preproc 0 hidden essing 1 shown SCROLLER ec of scroll wheel for view dis 1 to 299 ROTATOR Speed of rotation for view display 0 1 to 2 0 TRANSLATOR factor for view dis 0 1 to 2 0 In Figure JI you find an example of the definition file Z88ENVIRO DYN Z88ENVIRO DYN is also located in the subdirectory z88aurorav1 bin Selection operating system 52 Mah Aurora 126 Theory Manual Projektverzeichnis auch von der letzten Sitzung WORKPATH C z88auroravl docu bsp 2 Addons die hinzugeschaltet werden koennen ADDONS ADDONS ADDONS F LAGS FLAG FLAG FLAG FLAG FLAG FLAG FLAG FLAG FLAG FLAG FLAG FLAG PFADE PATH PALA PATH A01_GEOCON C z88auroravl addons geocon A02_TETGEN C z88auroravl addons tetgen A03_NETGEN C z88auroravl addons netgen zum Ansteuern der verschiedenen Optionen NODEPICK O RANDSTART O LANG 2 CPU il OOC_MEM 2000 OOC_PATH Cr TOOLBAR_IMP 0 TOOLBAR_VIEW 1 T
142. s Elements with 8 nodes Element type 7 Subdivide in local x direction three times equidistantly and subdivide in local y direction 5 times ascending geometrically The super element is supposed to have the number 31 Write e g into the middle of the ele ment with the TEXT function SE 31 11 73 E 5 L eorE for equidistant is equivalent For super elements 3 dimensional Hexahedrons No 10 66 Z66 Aurora 56 Theory Manual SE Element number Super element type Type of the finite elements to be produced by meshing Subdivision in local x direction Type of subdivision in local x direction Subdivision in local y direction Type of subdivision in local y direction Subdivision in local z direction Type of subdivision in local z direction Write into one line separate each item by at least one blank Example Subdivide an Isoparametric Serendipity Hexahedron with 20 nodes Element type 10 as super element into finite elements of the type Isoparametric Hexahedrons with 8 nodes Element type 1 Subdivide equidistantly three times in local x direction 5 times ascending geometrically in local y direction and subdivide equidistantly 4 times in local z direction The super element is supposed to have the number 19 Write e g into the middle of the element with the TEXT function SE 19 10 1 3 E 5 L 4 E eorE for equidistant is equivalent 5th step Define the Layer Z88NET and make it the active layer You need concentration for this step b
143. s acceptable Computing effort medium Size ee element stiffness matrix 18 x 18 Isoparametric Plate Element No 19 3 Cubic Isoparametric Lagrange element following Reissner Mindlin s theory Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 48 x 48 Isoparametric Plate Element No 20 y Quadratic Isoparametric Serendipity element following Reissner Mindlin s theory Quality of displacements very good Quality of stresses in the Gauss points good Quality of stresses in the corner nodes quite good Computing effort medium Size of element stiffness matrix 24 x 24 Y 4 11 IB or Theorie Manual AXISYMMETRIC PROBLEMS Torus No 6 Ds Linear function Quality of displacements average Quality of stresses in the corner nodes inaccurate Computing effort Low Size of element stiffness matrix 6 x 6 Z Y a Torus No S Ds Quadratic Isoparametric Serendipity element Quality of displacements very good Quality of stresses in the Gauss points very good Quality of stresses in the corner nodes good Computing effort High Size of element stiffness matrix 16 x 16 R X Torus No 12 DE Cubic Isoparametric Serendipity element Quality of displacements excellent Quality of stresses in the Gauss points excellent Quality o
144. s or principal or Tresca stresses Nodal forces in X Y and Z for each element and each node 125 Ue Theorie Manual 5 18 PLATE NO 18 WITH 6 NODES 5 This 1s a curvilinear Serendipity Reissner Mindlin plate element with square shape functions The transformation 1s isoparametric The integration is carried out numerically in both axes according to Gauss Legendre Consequently the integration order can be selected in Z8811 TXT in the material information lines The order 3 3 points is mostly sufficient re duced integration This element calculates both displacements and stresses quite good The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Area loads are defined in the appropriate material lines file Z8811 TXT instead of Second moment of inertia RIY Y For this element you need to set the plate flag IPFLAG to 1 Attention In contrary to the usual rules of the classic mechanics Z88 defines 6 the rotation around the X axis and 6 the rotation around the Y axis This element type is implemented for use with automeshers e g Pro MECHANICA for the 3D CAD system Pro ENGINEER by Parametric Technology Thus a mesh generation with ZSSN is not possible because this will make no sense Use plates No 20 for the mesher Z88N Because plates No 20 compute both the deflections and the stresses
145. same value as chosen in Z8811 TXT but different values are permitted 0 Calculation of the stresses in the corner nodes 1 7 13 Calculation of the stresses in the Gauss points e g 7 Gauss points See note for Z8811 TXT gt KFLAG has no meaning gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and normally not used here because it is much more convenient to enter the pressure data for the plate elements into Z8811 TXT in the section material information However the possibility for entering the pressure loads by the surface and pressure loads file Z88I5 TXT too is implemented for universal use of this file Then set IQFLAG to 1 and proceed as follows gt Element number with pressure load gt Pressure positive if pointing towards the edge Results Displacements in Z i e w and rotations 0 around X axis and 0 around the Y axis Stresses The stresses are calculated in the corner nodes or Gauss points and printed along with their locations The following results will be presented late bending moments M and M unit force x length length late torsion moments M My unit force x length length he shear forces Q and Q unit force length
146. select the short est straight edge of your model and conduct the meshing with for example half this value 3 Edge ratio The quotient of the longest and the shortest edge of a triangle is also a measure for its regularity Here you should select a value close to 1 Which CAD systems can cooperate with Z88GEOCON Any CAD systems which can export 1 e write STL files in ASCII format However we can not guarantee any success Which elements are supported by the converter Z88 Aurora first generates a visualisation from the imported STL files This can be trans ferred into structures from elements No 16 or No 17 linear or quadratic Tetrahedrons by means of the existing meshers How to proceed 1 Construct the 3D geometry to be calculated in your CAD system In the process please keep in mind the above mentioned particularities if possible Export the ge ometry as STL file It is recommended to check the original model and the interchange file with an integrated geometry check for defective and very small surfaces Have a closer look at the STL and search for triangles with very acute angles If they are lo cated in a part of the component which is important for the calculation it is recom mended to export the interchange file one more time with modified settings 2 In Z88 Aurora select File gt Import gt STL data In the subsequent selection box you can only select STL files Therefore select the desired file figure 3 T
147. sh transition haz structured L Advancing front ie Sweep o Bottom up Multiple Ok Use mapped meshing where appropriate Redefine Sweep Path Defaults Cancel Figure 24 and define a Section with this material Allocate your component to this Section Allocate either Hex or Tet as meshing properties Edit Material xX Name material 1 Description Material Behaviors General Mechanical Thermal Cther Elasticity Plasticity Hyperelastic Damage for Ductile Metals Hyperfoar Damage For Traction Separation Laws Hypoelastic Damage For Fiber Reinforced Composites Porous Elastic T F F F F By Damage For Elastomers Viscoelastic Deformation Plasticity Damping Expansion Brittle Cracking Mesh Controls x Element Shape Technique Algorithm O Asis Medial axis O Free 4 Minimize the mesh transition haz structured E Advancing front ie Sweep o Bottom up Multiple Ok Use mapped meshing where appropriate Redefine Sweep Path Defaults Cancel 4 Figure 24 and generate a mesh which meets your requirements 82 Ze 6 Aurora Edit Material xX Name Material 1 Description Material Behaviors General Thermal Other Mechanical Elasticity Plasticity Hyperelastic Damage For Ductile Metals Hypertoam Damage for Traction Separation Laws Hypoelastic
148. simulation tool in the industrial field offering a large range of performance as well as simple operation Due to the extensive range of func tions the following restrictions were made with regard to the functions of the converter One solid 1 instance with one material linear elastic can be converted The solid must consist of one element type Optional Cartesian boundary conditions forces Concentrated Force and pressure can be applied Which ABAQUS versions can cooperate with Z88 Aurora The converter at hand was tested with ABAQUS 6 8 4 therefore the full range of functions is available in this case Since the ABAQUS format is actually proprietary modifications can occur at any time influ encing the functionality of the converter Older versions of ABAQUS e g 6 6 or 6 7 also do not write any version information into the files Therefore a version dependent conversion is difficult as well Which elements are supported by the converter You can use any Tetrahedrons and Hexahedrons from ABAQUS but since normally no acoustic or thermal simulation data are exchanged between ABAQUS and Z88 Aurora the following element transformations will occur Conversion gt from C3D4 to element type 17 and vice versa Conversion gt from C3D10 to element type 16 and vice versa Conversion gt from C3D8 to element type 1 Conversion gt from C3D20 to element type 10 Which functions does the converter offer Import functions of the convert
149. sk of every FEA system the calculation of displacements is solved Thereupon the stresses are calculated and entered in Z8803 TXT afterwards the nodal forces are calculated and entered in Z8804 TXT Furthermore the solver generates two files Z8805 TXT and Z8808 TXT which are used for the communication with Z88 Aurora Z88 features three different solvers e lt A so called Cholesky solver without fill in It is easy to handle and very fast for small and medium structures However like any direct solver Z88F reacts badly on ill numbered nodes but you may improve the situation with the Cuthill McKee program Z88H Z88F is your choice for small and medium structures up to 20 000 30 000 degrees of freedom e A so called direct sparse matrix solver with fill in It uses the so called PARDISO solver This solver is very fast but uses very much dynamic memory It is your choice for medium structures up to 150 000 degrees of freedom on ordinary 32 bit PCs How 18 Z66 Aurora 126 Theory Manual ever we ve computed structures with 1 million of DOF very fast using a computer featuring 32 Gbyte of memory 4 CPUs 64 bit Windows version of Z88 A so called sparse matrix iteration solver It solves the system of equations by the method of conjugate gradients featuring SOR preconditioning or preconditioning by an incomplete Cholesky decomposition depending on your choice This solver deals with structures with more than 100 000 DOF
150. t 3 degrees of freedom for each node gt Element type is 17 gt 4 nodes per element gt Cross section parameter OPARA is 0 or any value has no influence gt Integration order INTORD for each mat info line I is usually good Allowed are I for 1 Gauss point 4 for 4 Gauss points and 5 for 5 Gauss points 124 Hah Aurora 126 Theory Manual Z8813 TXT gt Integration order INTORD for stress calculation Can be different from INTORD in Z88I1 TXT 0 Calculation of stresses in the corner nodes 1 4 5 Calculation of stresses in the Gauss points e g 4 4 Gauss points gt KFLAG any has no influence gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces pressure loads applied onto element no 17 gt Element number with pressure load gt Pressure positive if pointing towards the edge gt 3 corner nodes of the loaded surface Mathematically positive in plain view The local nodes 1 to 3 may differ from the local nodes 1 to 3 used for the coincidence Results Displacements in X Y and Z Stresses SIGXX SIGYY SIGZZ TAUXY TAUYZ TAUZX respectively for corner nodes or Gauss points Optional von Mise
151. t factor a is easy to handle The SOR precondi tioning needs less memory but the control parameter the relaxation parameter cannot be determined a priori In addition you must enter several parameters into the file Z88MANAGE TXT This is done via extended options in the menu Solver e termination criterion maximum count of iterations e g 10000 e termination criterion residual vector lt limit Epsilon e g le 7 e parameter for the SIC convergence acceleration Shift factor Alpha from 0 to 1 good values may vary from 0 0001 to 0 1 start with 0 0001 For further information con sult the literature e Parameter for the SOR convergence acceleration Relaxation factor Omega from 0 to 2 good values may vary from 0 8 to 1 2 e Number of CPUs NOTE The files Z88I1 TXT Z88I2 TXT Z88I3 TXT Z88I5 TXT Z88MAT and Z88MANAGE TXT mentioned here are described more precisely in chapter 3 87 Ue Theorie Manual General F Warning Repeated node sorts may produce worse numbering 4 Number of CPUs to be used during calculation Iterative solvers Max iterations 10000 Important for huge FE structures Residuum 1e 007 Sum of error to analytic result alpha SIC 0 0001 Shift factor for partial Cholesky decomposition recommended 0 0001 0 000001 omega SOR 1 1 Factor for successive overrelaxation SOR recommended 0 3 1 2 Direct solver Pardiso L OOC memory MB 1000 Memory used in out of core
152. t load cases additionally the calculation can be con ducted with mass properties As At the moment only the calculation of one load case 1s possible Mind the following formats Long 4 bytes or 8 bytes integer number Double 8 bytes floating point number alternatively with or without point 1 input group Number of boundary conditions loads The boundary conditions are allocated to a load case the mass property 1s defined Ist number Number of boundary conditions loads Long A 2nd number number of the load case A 3rd number MGFLAG A 4th number gravity vector X coordinate A Sth number gravity vector Y coordinate A 6th number gravity vector Z coordinate A further entry into 1 input group Name of the load case A Explanation MGFLAG If the calculation includes a mass property the mass flag must be set to 1 otherwise 1t must be o0 nd 2 input group The boundary conditions and loads are defined For every boundary condition and for every load respectively one line Ist number node number with boundary condition load or constraint Long 2nd number Respective degree of freedom 1 2 3 4 5 6 Long 3rd number Header flag 1 force Long or 2 displacement Long 4th number Value of the load or displacement Double Example The node I shall be fixed respectively at his 3 degrees of freedom support Node 3 gets a load of 1 648 N in Y direction i e DOF 2 the degrees of freedom 2 a
153. t material for calculation Very often input files are produced much faster than by any interactive queries Many input lines are similar to prior lines Use the block operations of your editor for copying Every FEA program can and so does Z88 Aurora produce a huge amount of data junk from time to time You are very often interested only in very specific results e g of special nodes The output files are simple ASCII files You can edit and shorten them as you like and print only the really interesting results Downward compatibility Z88 V13 0 files are completely compatible Z88 files for V11 0 and V12 0 are compatible if the the plate flag and the surface and pressure loads flag are supplied The import functions of Z88 Aurora include all possibilities to import existing Z88 files and to continue using them in Z88 Aurora This is why we do not want to refrain from explaining the input and output of the program Z88 Aurora is supposed to be as transparent to experienced users as the reliable Z88 Rules for entering values There is no need for special rules or field divisions only the usual C rules apply e All values are to be separated by at least one blank e Integer numbers may contain any point or exponents e For floating point numbers no points need to be provided e Numerical values which are O zero have to be entered explicitly Integer numbers Right i 345 55555 0 Wrong l 345 S5555E 0 no entry Floating point numbers Z88
154. t of inertia RIZZ bending around z z axis gt Max distance EZZ from neutral axis z z gt Second moment of area torsion RIT gt Second modulus torsion WT Z8813 TXT Beams No 2 have no influence However Z8813 TXT must exist with any content Results Displacements in X Y and Z and rotations around X Y and Z Attention DOFS not right hand rule see below Stresses SIGXX TAUXX Direct stress shear stress SIGZZ1 SIGZZ2 Bending stress around z z for node 1 and node 2 SIGYY1 SIGY Y2 Bending stress around y y for node 1 and node 2 Nodal forces in X Y and Z and nodal moments around X Y and Z for each element and each node 100 LBs Es Algebraic sign Y YA A y A A J2 J2 US i A LS Xx x gt B D a E D 1 Jf 2 fy 1 f 2 X Y plane X Z plane 101 LIB Theorie Manual 5 3 PLANE STRESS TRIANGLE NO 3 WITH 6 NODES This is a simple triangular plane stress element with complete square shape functions This element is obsolete and kept in Z88 only for studies Elements No 7 11 or 14 are much bet ter Pay attention to edge loads cf chapter 3 4 No entries into the surface and pressure loads file Z8815 TXT Input CAD see chapter 2 7 2 1 4 2 5 3 6 1 7881 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt 2 degrees of freedom for each node gt Element type is 3 gt 6 nodes per element gt Cross section parameter O
155. tegration order can be selected in Z8811 TXT in the material in formation lines The order 3 is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly Pay attention to edge loads when using forces cf chapter 3 4 It is easier to enter edge loads via the surface and pressure loads file Z88I5 TXT You may combine this element with elements no 15 Torus elements No 8 can be generated by the mesh generator Z88N from the super elements torus elements No 8 or No 12 Thus Torus No 8 is well suited as super element Input CAD see chapter 2 7 2 1 5 2 6 3 7 4 8 7881 TXT gt In principle cylindrical coordinates are expected KFLAG must be 0 R coordinate X always positive Z coordinate Y always positive gt IOFLAG 1 if edge loads for this element are filed in Z8815 TXT gt 2 degrees of freedom for each node DOF R and Z X and Y gt Element type is 8 gt 8 nodes per element gt Cross section parameter OPARA is 0 or any value no influence gt Integration order per each mat info line 3 is usually good Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z88I1 TXT but different values are permitted 0 Calculation of the str
156. tem by at least one blank Make sure to write in the layer Z88FLA 9th step Export store your model or drawing under the name Z88X DXF in the DXF file format For precision of decimal positions take the default value which the CAD program suggests Take care that you export directly into the Z88 directory or you must copy the file Z88X DXF by hand into the Z88 directory because the CAD converter Z88X expects the in put and output files in the same directory where Z88X is located You may launch the CAD converter Z88X then 75 LIB Theorie Manual Note If you want to convert Z88 text files as Z88X DXF to CAD you can choose the text size which applies to all texts like node numbers element numbers etc This is very important from time to time because there 1s no possibility in e g AutoCAD to change the text size globally afterwards From time to time you must make some tries until you have found the suitable text size for the respective Z88 file Simply call Z88X once more with another text SIZe Windows In Z88X File gt Text size UNIX 288x iltx iatx nitx ilfx iafx nifx ts number Caution valuable note Use the Z88X keywords P number FE values SE values MAT RBD Z88NI TXT Z88I1 TXT Z8812 TXT and Z88B TXT only where they are really needed Take care that they do not appear in other drawing captions 76 Zod Aurora 56 Theory Manual 4 1 8 THE 3D CONVERTER Z88G Sometimes 3D CAD programs include so cal
157. that Z88 DYN determines the language for Z88 Aurora and any accessed Z88 modules For the allocation of memory the file possesses dif ferent parameters which define the maximum possible size of structures to be computed MAXK for example determines the maximum number of nodes for the finite element calcu lation At the end of this chapter you will find a list of all control parameters If it becomes apparent during the use of Z88 Aurora that the memory does not suffice you will get a re spective error message see Figure 8 e warning A Memory overflow Increase MAXLASTF Figure 8 Memory overflow because of too many nodes After that the dialog box Options opens where the respective parameter can be increased under the tab Memory see Figure 9 The memory parameters always have an offset of about five for safety and stability reasons Thus for the calculation of a model with 1000 nodes the memory parameter MAXK must be set to 1005 After closing the dialog box Z88 Aurora is quitted In the background the definition file was changed according to the adjustments When running Z88 Aurora next time these changes are taken into account There will be no data loss The memory parameters can also be edited without previous memory overflow alert For this purpose select the function Options in the menu Help The tab Memory contains all memory parameters After closing the dialog box the file Z88 DYN is updated and you return
158. the procedure when using them is explained in detail You have the following possibilities as Z88 import Data from Z88 V13 can be further used in Z88 Aurora STEP import You can import 3D geometry data in the STEP data format according to DIN ISO 10303 AP 203 and AP 214 This format is supported by most 3D CAD sys tems DXF import and export You have the possibility to import 2D and 3D FE structures which were generated in a 2D CAD system preferably AutoCAD to edit them or to directly calculate them In the same way FE structures can be written as dxf again STL import Z88 processes stereo lithography data which contain a triangulated 3D structure This format is also typically used as input data for CAM programs That is why most CAD programs can generate this file type 19 Es Ke we 2 Us Theorie Manual NASTRAN import The CAD system Pro ENGINEER and other commercial programs can write FE data continuum elements and boundary conditions as nas file These can be directly imported into Z88 Aurora ABAQUS import and export Similar to the NASTRAN case the input files inp of the program ABAQUS can be edited Additionally FE data generated in Z88 Aurora can be exported as input files ANSYS import Direct transformation of ANSYS data into data for Z88 Aurora COSMOS import The import of COSMOS files known from previous versions is still supported IV THE MESH GENERATOR FOR ORDERED MESHES The
159. this version For this purpose it is often sufficient to add single flags or value according to a V13 manual Which elements are supported by the converter Of course you can use any element known from previous Z88 releases Which functions does the converter offer Import functions of the converter Conversion gt from Z8811 TXT V13 to Z8811 TXT Conversion gt from Z8812 TXT V13 to Z8812 TXT Import gt from Z8813 TXT VI3 into the option settings of ZSS Aurora Conversion gt from Z88I5 TXT V13 to Z88I5 TXT 474 Z88 input file x 2 z88auroravl docu bsp 2 oe E Recently Used B b1_2 txt 22 03 2006 5 Tom Desktop amp Main C b1_3 txt z88il txt z88i2 txt 03 03 2010 02 03 2010 02 03 2010 DVD RWeLaufwerk D z8813 txt 02 03 2010 4 BD ROM Laufwerk F z88manage txt 02 03 2010 O DVD RWeLaufwerk z88mat txt 02 03 2010 z88ni bdt 02 03 2010 z8800 txt z8801 txt z8802 txt z8803 txt z8804 txt z8805 txt z8808 txt 02 03 2010 02 03 2010 02 03 2010 02 03 2010 02 03 2010 02 03 2010 02 03 2010 df i m Add Remove bd choose Z88 input file Structural information z88il txt Meshing file z88ni txt Boundary conditions z88i2 txt Stress parameters z88i3 txt Surface pressure loads z88i5 txt Figure 15 Import of files from previous Z88 versions into Aurora 58 Zod Aurora 126 Theory Manual How to proceed 1 First you must import the structur
160. tion ISODSS of Z88 uses internally these values integration order 1 or 2 in Z8811 TXT 3 Gauss points integration order 4 in Z8811 TXT 7 Gauss points Example Z8811 TXT uses an entry of 2 for INTORD Thus plane stress elements No 7 use 2X2 4 Gauss points and plane stress elements No 14 use 3 Gauss points for integra tion Z8813 TXT gt Integration order INTORD Basically it is a good idea to use the same value as chosen in Z8811 TXT but different values are permitted 118 Zod Aurora 126 Theory Manual 0 Calculation of the stresses in the corner nodes 1 7 13 Calculation of the stresses in the Gauss points e g 7 Gauss points See note for Z8811 TXT gt KFLAG 0 Calculation of SIGXX SIGYY and TAUXY gt KFLAG 1 Additional calculation of SIGRR SIGTT and TAURT gt Reduced stress flag ISFLAG 0 no calculation of reduced stresses 1 von Mises stresses computed for the Gauss points INTORD not 0 2 principal or Rankine stresses computed for the Gauss points INTORD not 0 3 Tresca stresses computed for the Gauss points INTORD not 0 Z8815 TXT This file is optional and only used if in addition to nodal forces edge loads applied onto element no 14 gt Element number with surface and pressure load gt Pressure positive if pointing towards the edge gt Tangential shear positive in local r direction gt 2 corner nodes and one mid node of the loaded surface Mathematically positive in plain vi
161. tion order 0 to 4 KFLAG 0 or 1 Von Mises stresses 0 or 1 Write into one line separate each item by at least one blank Make sure to write in the layer Z88GEN Example The structure uses finite elements type 7 The stress calculation is supposed to be carried out in 3 3 Gauss points per element stresses are supposed to be calculated in addition radially and tangentially Compute von Mises stresses too Thus ZSS 3 TXT 3 1 1 7th step Define the Layer Z88RBD and activate it Write with the TEXT function into a free space well into any place of your drawing 73 LIB Theorie Manual 7 1 number of the boundary conditions i e the first input group of the boundary condition file Z8812 TXT Z8812 TXT Number of the boundary conditions Write into one line separate each item by at least one blank Make sure to write in the layer Z88RBD Example The structure has 10 boundary conditions e g two loads and eight constraints 1 e support reactions Thus Z88I2 TXT 10 7 2 Boundary conditions the second input group of the boundary condition file Z8812 TXT RBD Number of the boundary condition node number Degree of freedom Header flag force displacement 1 or 2 Value Write into one line separate each item by at least one blank Make sure to write in the layer Z88RBD Example The structure shall be a truss framework Node 1 shall be fixed in Y and Z node 2 fixed in X and Z Nodes 7 and 8 have a load of 30 000 N each
162. u preprocessor with launch icon Super Elements of the mesh generator Z88N A mesh generation is only sensible and permitted for continuum elements An overview of the possible finite element structures can be found in Table 7 91 IB Theorie Manual Table 7 Possible super structures in Z88 Aurora Superstructure Finite Element Structure Plane Stress Element No 7 Plane Stress Element No 11 7 Mixed structures e g containing Plane Stress Elements No 7 and Trusses No 9 cannot be processed In such a case let the mesh generator process a super structure containing no trusses After wards you can either insert the additional trusses manually in Z88 Aurora or you can export the file created by the mesh generator by means of the DXF converter import this DXF file into the CAD system and insert the trusses there you can also define the boundary conditions at the same time or edit them in Z88 Aurora Subsequently re import the DXF file into Z88 Aurora Mode of operation of the mesh generator For generating FE meshes proceed as follows The continuum is described by so called super elements short SE which practically corresponds to a quite rough FE structure The super structure is then subdivided This is done super element wise starting with SE 1 SE 2 up to the last SE SE 1 produces the finite elements short FE 1 to Jj SE 2 the FE j 1 to k SE 3 the FE k 1 to m and so on Within the SE the direction of the local coo
163. uadratic Tetra hedrons by means of the existing meshers Which functions does the converter offer Z88Geokon gt Conversion gt from step or stp to visualised super structure Z8811 txt How to proceed 1 Construct the 3D geometry to be calculated in your CAD system In the process please keep in mind the above mentioned particularities if possible Export the ge ometry as STEP AP203 or AP214 file Please take care to export a volume model not 2D or wireframe model It is recommended to check the original model and the inter change file with an integrated geometry check for defective and very small surfaces 2 In Z88 Aurora select File gt Import gt STEP data In the subsequent selection box you can only select STEP files Therefore select the desired file Figure 17 3 From your file Z88Geokon generates an STL which is required for visualisation in Z88 Aurora This data type can now be meshed and processed The same functionalities are available when you access the STEP import via the toolbar 8 Recently Used gt Tom DVD RW Laufwerk D e BD ROM Laufwerk F DVD RW Laufwerk Figure 1 8 Importing STEP files 60 Zod Aurora 56 Theory Manual 4 1 3 THE STL CONVERTER Z88GEOCON STL What is the basic idea and which are the features Like STEP STL stereo lithography is an established and standardised interchange format which can be generated from many CAD and CAM systems and is
164. ues e g 1000 use the menu View gt Z limit towards you For further information regarding the application and options of postprocessing please con sult the Z88 Aurora User Manual 97 LIB Theorie Manual 5 DESCRIPTION OF THE FINITE ELEMENTS s1 HEXAHEDRON NO 1 WITH 8 NODES The hexahedron element calculates deflections and stresses in space It is a transformed ele ment therefore it can have a wedging form or another oblique angled form The transforma tion is isoparametric The integration is carried out numerically in all three axes according to Gauss Legendre Thus the integration order can be selected in Z88I1 TXT in the material information lines The order 2 is mostly sufficient Hexahedron No 1 is also well usable as a thick plate element if the plate s thickness is not too small against the other dimensions The element causes high computing load and needs a lot of memory because the element stiffness matrix has the order 24x24 Hexahedrons No 1 can be generated by the mesh generator Z88N from super elements Hexa hedrons No 10 and Hexahedrons No 1 Input CAD see chapter 2 7 2 Upper plane 1 2 3 4 1 quit LINE function Lower plane 5 6 7 8 5 quit LINE function 1 5 quit LINE function 2 6 quit LINE function 3 7 quit LINE function 4 8 quit LINE function 7881 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt IOFLAG 1 if surface and pressure loads for this
165. ume Here too you must enter the appropriate data 1 e what you have already designed in Pro ENGINEER Before running the conversion choose the right type of elements The generation of volumes is easy but the generation of plane stress elements plates and to rus elements axisymmetric elements 1s tricky First build a volume with small thickness in Pro E Set reference points especially for axis symmetric elements Launch Pro MECHANICA and idealize the volume into shells Model gt Idealizations gt Shells gt Midsurfaces This eliminates the depth When working with axis symmetric elements keep in 78 y Minj urora Theory Manual mind that you are working in cylinder coordinates Your coordinate system coincidates with the axis of rotation and the volume lies on the corresponding radiuses see figure Please keep in mind These FEA output data formats especially the NASTRAN format are modified almost on a daily basis Anyway Z88G looks quite harmless but properly operated Z88G is a mighty tool which al lows you to file very large FEA structures to Z88 eet eee eee 7 El MC pe gt PF al 25 Ss e Erfolgreich zu Verzeichnis C proe ge ndert ta e Schattiertes Modell wird angezeigt S Zoom Bereich durch Anklicken zweier Stellen definieren Kl This is how tori are generated in Pro ENGINEER Wildfire In case of plates and shells pro ceed correspondingly 4 1 9 THE ANSYS CONVERTER Z88AN
166. vilinear Serendipity volume shell element The transformation is isoparametric The integration is carried out numerically in all axes according to Gauss Legendre The ele ment can be arbitrarily curved it is actually a hexahedron with square shape functions on the surface and linear shape functions in the thickness direction The integration order can be se lected in Z8811 TXT in the material information lines The order 3 1 e 3x3 Gauss Points is mostly sufficient This element calculates both displacements and stresses very exactly The integration order can be chosen again for the stress calculation The stresses are calculated in the corner nodes good for an overview or calculated in the Gauss points substantially more exactly The three degrees of freedom are the global displacements in X Y and Z There are no rota tional degrees of freedom since it is a volume element The Element can be generated by the mesh generator Z88N Type 21 gt Type 21 Input CAD upper plane 1 5 2 6 3 7 4 8 1 lower plane 9 13 10 14 11 15 12 16 9 Lines 1 9 2 10 3 11 4 12 see chapter 4 1 7 Z8811 TXT gt KFLAG for Cartesian 0 or cylindrical coordinates 1 gt surface and pressure loads flag IOFLAG 1 if entry of surface and pressure loads via Z8815 TXT gt 3 degrees of freedom for each node gt Element type is 21 gt 16 nodes per element gt Cross section parameter OPARA is insignificant gt Integration order for each mat in
167. w It uses no approximate solution compared to the continuum elements Y algebraic sign Input CAD see chapter 2 7 2 Line from node 1 to node 2 7881 TXT gt KFLAG for Cartesian 0 or polar coordinates 1 gt Set beam flag IBFLAG to 1 gt 3 degrees of freedom in a node gt Element type is 13 gt 2 nodes per element At the material information lines gt Any integration order INTORD 1 4 has no influence gt Cross sectional area OPARA gt Insert 0 for second moment of inertia RIYY bending around y y axis gt Insert 0 for max distance EYY from neutral axis y y gt Second moment of inertia RIZZ bending around z z axis gt Max distance EZZ from neutral axis z z gt Insert 0 for second moment of area torsion RIT gt Insert 0 for second modulus torsion WT Z8813 TXT Beams No 13 have no influence However Z8813 TXT must exist with any content Results Displacements in X and Y and rotations around Z Stresses SIGXX TAUXX Direct stress shear stress SIGZZ1 SIGZZ2 Bending stress around z z for node 1 and node 2 Nodal forces in X and Y and nodal moments around Z for each element and each node 117 LIB Theorie Manual 5 14 PLANE STRESS ELEMENT NO 14 WITH 6 NODES This is a curvilinear Serendipity plane stress element with square shape functions The trans formation is isoparametric The integration is carried out numerically according to Gauss Legendre Consequently the integr
168. x ox Y trussNo 9 feat xx x x x Y beamNo 2 exact o oe ooo x x Y beamNo 13 feat x x e x y camNo S exe _x x x x Y i i iin ic ISA SISISIS SISISIS NENI el o 21 LOG haora Theorie Manual 3 THE INPUT AND OUTPUT OF Z88 AURORA Generally the input and output files in Z88 Aurora unlike in Z88 are created while operating the user interface Of course it is possible to import and edit existing Z88 V13 input files into Z88 Aurora Additionally all boundary conditions from existing files can be edited and altered directly on the Z88 Aurora user interface The following table offers an overview of the input and output files Table 2 Input and output of Z88 Aurora modification 88 DYN memory amp language header file Zas FCD fonts colors dimensions header file 88ENVIRO DYN setting variables Aurora Z SS8BMANAGE TXT header file Aurora S8MAT TXT Material data Aurora MAT CSV OORLPLTAT structure data of beams and plates for Aurora Lt a Eingabedateien 2 ce 78811 TXT j general structur file for computation and display in Z88 Aurora Z8812 TXT constraints for computation and display in 288 Aurora 8818 TXT stress parameter header file 2815 TXT line and surface loads input for internal use Z880 for peculiar frequencies for internal use Z880 mport Exportdateien OO ANS ANSYS FE file for converter Z88ANS_ _

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