Transcript No Slide Title

3.5 ANSYS/LS-DYNA Enhancements
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
Contact
2D, box IDs, part asmb, tied shell-edge to surface
Restarts
Change settings, rigid/deformable conversion, etc.
Misc.
EDREAD (ASCII Files) & Drop Test Module (DTM)
Workshop
20-30 minute exercise showing several new features
NEW FEATURES 5.7
Elements
Training Manual 001419
15 Aug 2000
3.5-1
ANSYS/LS-DYNA Enhancements
2D Elements
• PLANE162 - 2D, 4-Node Solid
– 3-node triangle available (not recommended)
– 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)
NEW FEATURES 5.7
– Only Lagrangian formulation supported
– 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
ANSYS/LS-DYNA Enhancements
Materials
• New TB,DISCRETE,,,,TBOPT for COMBI165
– 8 spring/damper materials instead of real constants
– 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)
NEW FEATURES 5.7
– COMBI165 part selection/plotting restriction lifted
Training Manual 001419
15 Aug 2000
3.5-3
ANSYS/LS-DYNA Enhancements
…Materials
• Steinberg plasticity via TB,EOS,,,,5,EOSOPT
– Deformations of solids at high strain rates with failure
– 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
NEW FEATURES 5.7
– Yield strength a function of temperature and pressure
– Available only for shell elements
Training Manual 001419
15 Aug 2000
3.5-4
ANSYS/LS-DYNA Enhancements
Part Inertia
• EDIPART Defines inertia for rigid bodies
– 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)
NEW FEATURES 5.7
– Default is to have LS-DYNA calculate rigid body inertia
properties from the finite element mesh
– 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
ANSYS/LS-DYNA Enhancements
Loading
• EDLOAD,,LAB
(LAB = RBOX, RBOY, RBOZ)
– Rigid body rotational velocities now supported
– 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)
NEW FEATURES 5.7
• EDLOAD,,LAB,KEY (KEY = CID = Local CS no.)
– 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
ANSYS/LS-DYNA Enhancements
…Loading
• EDVEL,Option, …
New initial velocity command
– VGEN - Option corresponding to old EDIVELO command
– 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
NEW FEATURES 5.7
– VELO - Option that can also be used in small restart
analyses (i.e., not limited to only new analyses)
– 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
ANSYS/LS-DYNA Enhancements
Contact
• EDASMP,,ASMID,PART1, PART2, …,PART16
– Up to 16 Parts can be grouped into an assembly
– 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)
NEW FEATURES 5.7
– ASMID = part assembly no. (greater than highest part no.)
– FS (static coefficient of friction) also supported
– Subcycling (EDCSC) not supported with 2D contact
Training Manual 001419
15 Aug 2000
3.5-8
ANSYS/LS-DYNA Enhancements
...Contact
• EDCGEN,TSES - Tied shell-edge to surface contact
– Glues the edge of a shell to another surface
• 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
NEW FEATURES 5.7
– Not applicable with rigid bodies
– EDDC replaces old EDCDELE command
• EDCLIST,NUM - Limit Contact Entity Listing
Training Manual 001419
15 Aug 2000
3.5-9
ANSYS/LS-DYNA Enhancements
Restarts
• EDSTART,RESTART - Small restarts expanded
– Most LS-DYNA options now supported for RESTART=2
– 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
NEW FEATURES 5.7
• New commands supporting small restarts
– 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
ANSYS/LS-DYNA Enhancements
Miscellaneous
• EDREAD,NSTART,Label,NUM,STEP1,STEP2
– Labels NODOUT and RBDOUT now supported
– 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)
NEW FEATURES 5.7
– NUM = Node # (NODOUT) or Part # (RBDOUT)
• 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
ANSYS/LS-DYNA Enhancements
Workshop
• 20-30 minute exercise
showing new features:
– Mooney-Rivlin input
– Part inertia definitions
– Discrete material input
– Issuing a small restart
– Termination criteria
– Switch from deformable
to rigid and back again
NEW FEATURES 5.7
– Initial velocity format
• See commented input
file for more details …
Training Manual 001419
15 Aug 2000
3.5-12