1 / 12

3.5 ANSYS/LS-DYNA Enhancements

3.5 ANSYS/LS-DYNA Enhancements. Elements 2D axisymmetric, plane stress, or plane strain Materials Discrete, Mooney-Rivlin, Steinberg, Trans Aniso FLD Part Inertia User-defined rigid body properties Loading Local CS, birth/death, RB omega loads, EDVEL

odell
Download Presentation

3.5 ANSYS/LS-DYNA Enhancements

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 3.5 ANSYS/LS-DYNA Enhancements Elements2D axisymmetric, plane stress, or plane strain MaterialsDiscrete, Mooney-Rivlin, Steinberg, Trans Aniso FLD Part InertiaUser-defined rigid body properties LoadingLocal CS, birth/death, RB omega loads, EDVEL Contact2D, box IDs, part asmb, tied shell-edge to surface RestartsChange settings, rigid/deformable conversion, etc. Misc.EDREAD (ASCII Files) & Drop Test Module (DTM) Workshop 20-30 minute exercise showing several new features Training Manual 001419 15 Aug 2000 3.5-1

  2. ANSYS/LS-DYNA Enhancements2D Elements • PLANE162 - 2D, 4-Node Solid • 3-node triangle available (not recommended) • Only Lagrangian formulation supported • UX, UY, VX, VY, AX, AY degrees of freedom • Y axis = symmetry axis for axisymmetric model • NO mixing of 2D and 3D element types permitted • PLANE162 KEYOPT Settings: • Keyopt(2) - Area weighted or volume weighted (AXISYM) • Keyopt(3) - Plane stress, axisymmetric, or plane strain • Only one 2D type can be used in any given analysis (i.e., you cannot have both axisymmetric and plane stress elements present in the same model) Training Manual 001419 15 Aug 2000 3.5-2

  3. ANSYS/LS-DYNA EnhancementsMaterials • New TB,DISCRETE,,,,TBOPT for COMBI165 • 8 spring/damper materials instead of real constants • COMBI165 part selection/plotting restriction lifted • Dummy material properties no longer needed • Modified TB,MOONEY,,,,TBOPT • TBOPT=0 - Direct input of Mooney-Rivlin coefficients • TBOPT=2 - Input test data (stress/strain or load/deflection) Training Manual 001419 15 Aug 2000 3.5-3

  4. ANSYS/LS-DYNA Enhancements…Materials • Steinberg plasticity via TB,EOS,,,,5,EOSOPT • Deformations of solids at high strain rates with failure • Yield strength a function of temperature and pressure • Equation of State (EOS) used to determine pressure • Transversely anisotropic FLD via TB,PLAW,,,,10 • Simulation of sheet forming processes • Flow Limit Diagram to compute maximum strain ratio • Available only for shell elements Training Manual 001419 15 Aug 2000 3.5-4

  5. ANSYS/LS-DYNA EnhancementsPart Inertia • EDIPART Defines inertia for rigid bodies • Default is to have LS-DYNA calculate rigid body inertia properties from the finite element mesh • Specifying properties is more accurate than the default when the object is complicated and the mesh is coarse • Allows meshing only a portion of the total structure • Parts must already be defined (EDPART,CREATE) • Specify inertia properties and initial conditions • Location of center of mass (X, Y, Z) • Translational mass • Inertia tensor (IXX, IXY, IXZ, IYY, IYZ, IZZ) • Initial velocity (RBVX, RBVY, RBVZ, RBOX, RBOY, RBOZ) Training Manual 001419 15 Aug 2000 3.5-5

  6. ANSYS/LS-DYNA EnhancementsLoading • EDLOAD,,LAB (LAB = RBOX, RBOY, RBOZ) • Rigid body rotational velocities now supported • EDLOAD,,LAB,KEY (KEY = CID = Local CS no.) • Apply loads in local CS (CID vector defined with EDLCS) • CID not valid for LAB = PRESS, ACLX/Y/Z, OMGX/Y/Z • Local CS for input only (output in global Cartesian CS) • EDLOAD,,, ,,, ,,,,BTIME,DTIME (Load birth and death) • BTIME valid for UX, ROTX, VX, AX, PRESS, RBUX, RBRX, RBVX, RBOX labels (and corresponding Y & Z labels) • DTIME valid for the above, with the exception of PRESS • CID, BTIME, & DTIME restrictions are in LS-DYNA Training Manual 001419 15 Aug 2000 3.5-6

  7. ANSYS/LS-DYNA Enhancements…Loading • EDVEL,Option, … New initial velocity command • VGEN - Option corresponding to old EDIVELO command • VELO - Option that can also be used in small restart analyses (i.e., not limited to only new analyses) • VGEN and VELO cannot both be used in same analysis • PHASE field of *INITIAL_VELOCITY_GENERATION automatically set based on EDDRELAX value: • PHASE=0 for EDDRELAX,OFF (or not issued) • PHASE=1 for EDDRELAX,DYNA or EDDRELAX,ANSYS • PHASE applicable to EDVEL,VGEN (not EDVEL,VELO) and determines what geometry (0=undeformed or 1=deformed) that velocities are applied to. No user input required! Training Manual 001419 15 Aug 2000 3.5-7

  8. ANSYS/LS-DYNA EnhancementsContact • EDASMP,,ASMID,PART1, PART2, …,PART16 • Up to 16 Parts can be grouped into an assembly • ASMID = part assembly no. (greater than highest part no.) • Cont and Targ fields of EDCGEN permit ASMID value • EDCGEN,ASS2D,Cont,Targ,FS • For 2D, only Automatic Single Surface Contact supported • Cont default is to use entire model (Targ not used) • Cont can also be limited to a part assembly (EDASMP) • FS (static coefficient of friction) also supported • Subcycling (EDCSC) not supported with 2D contact Training Manual 001419 15 Aug 2000 3.5-8

  9. ANSYS/LS-DYNA Enhancements...Contact • EDCGEN,TSES - Tied shell-edge to surface contact • Glues the edge of a shell to another surface • Not applicable with rigid bodies • EDBX,,BOXID,XMIN,XMAX,YMIN,YMAX,ZMIN,ZMAX • Box-shaped volumes used to further restrict contact • EDCGEN,,Cont,Targ,,,,,,,,,,,,,BOXID1,BOXID2 • Cont and Targ must be part IDs or part assemblies • EDDC - Delete, Deactivate, or Reactivate Contact • EDDC replaces old EDCDELE command • EDCLIST,NUM - Limit Contact Entity Listing Training Manual 001419 15 Aug 2000 3.5-9

  10. ANSYS/LS-DYNA EnhancementsRestarts • EDSTART,RESTART - Small restarts expanded • Most LS-DYNA options now supported for RESTART=2 • New commands supporting small restarts • EDSP - Small penetration checking for contact entities • EDRC - Specifies rigid/deformable switch controls • EDRD - Switches parts from deformable to rigid & back • EDRI - Define inertia props. for new rigid body from EDRD • EDTERM - Specifies various termination criteria • EDDUMP - Specifies output frequency for D3DUMP file • EDDC and EDVEL commands previously discussed • Many other commands enhanced (EDWRITE, etc.) Training Manual 001419 15 Aug 2000 3.5-10

  11. ANSYS/LS-DYNA EnhancementsMiscellaneous • EDREAD,NSTART,Label,NUM,STEP1,STEP2 • LabelsNODOUT and RBDOUT now supported • NUM = Node # (NODOUT) or Part # (RBDOUT) • STEP1,STEP2 - read data for specified load step range • EDREAD routine rewritten to parse ASCII strings into the appropriate fields (more robust at interpreting data) • Drop Test Module - DTM converted to Tcl/Tk • UIDL character restrictions removed (no longer cryptic) • ANSYS/LS-DYNA User’s Guide is now on-line • Windows launcher for LS-DYNA executable (beta) • Submit edited .K input files from Start > Program Files … Training Manual 001419 15 Aug 2000 3.5-11

  12. ANSYS/LS-DYNA EnhancementsWorkshop • 20-30 minute exercise showing new features: • Mooney-Rivlin input • Initial velocity format • Part inertia definitions • Discrete material input • Issuing a small restart • Termination criteria • Switch from deformable to rigid and back again • See commented input file for more details … Training Manual 001419 15 Aug 2000 3.5-12

More Related