Altair Radioss 2021.1 Release Notes

Highlights

  • Better support of LS-DYNA format keywords
  • Improved ease of use with more automatic parameter setting and automatic model correction
  • Better robustness and compatibility between different Radioss options
  • Update of the coupling library with MADYMO 2020.1

New Features

Monitored volume
  • Automatic correction of external surface normals to have them outward oriented.
  • Automatic closing of open external surface of the monitored volume with a simple flat surface.
Engine file command line
  • New option to read and write file hst_input.hstp (for better integration in HyperStudy).
    • -HSTP_WRITE: Radioss Starter writes the parameters (/PARAMETER) in the file hst_input.hstp.
    • -HSTP_READ: Radioss Starter reads parameter values from the file hst_input.hstp.
  • New option to define nodal random distribution (noise) from the Starter command line:
    • -rxalea <random value>: to define the noise amplitude.
    • -rseed <seed value>: to initialize the random distribution.
  • These options are available in the argument list of the Altair Compute Console.
Penality contact
  • Thermal behavior is added in the contact interface /INTER/TYPE25 (for the node to surface part of the contact).
  • Friction models are now available for the edge-to-edge behavior of the contact interface /INTER/TYPE25.
Material
  • /MAT/LAW109: New tabulated elasto-plastic material with strain rate and temperature dependency, linear and logarithmic strain rate interpolation.
  • /MAT/LAW110 (VEGTER): New material with Corus-Vegter material formulation.
  • /MAT/LAW78: New yield surface option with Barlat 3 parameter plane stress and correction of the constitutive material formulation.
Nodal time step (/DT/NODA)
  • New option to define the minimum time step with respect to the initial mass added ratio to the model (1st cycle).
Rigid body (/RBODY)
  • New force failure parameters for normal and shear directions (defined from main node to secondary node).
Transformation (/TRANSFORM)
  • New transformation option /TRANSFORM/POSITION to position a submodel or a set of nodes from 3 start nodes (or points) to 3 target nodes (or points).
Integrated beam element (/PROP/TYPE18)
  • New output stress and strain tensor results for any integration point of the integrated beam element (/PROP/TYPE18) in the H3D files and time history file.
    • /H3D/BEAM/TENS/STRESS/NPT=i,ALL
    • /H3D/BEAM/TENS/STRAIN/NPT=i,ALL
    • /TH/BEAM
State file (/STATE)
  • The card /BEGIN is added in the state file (.sta) with the working unit defined in the model.
LS-DYNA reader
  • The following additional keywords can be read:
    • *BOUNDARY_PRESCRIBED_MOTION_RIGID
    • *CONSTRAINED_INTERPOLATION
    • *CONSTRAINED_JOINT_PLANAR
    • *CONSTRAINED_JOINT_UNIVERSAL
    • *CONTACT_AUTOMATIC_NODES_TO_SURFACE
    • *CONTROL_OUTPUT
    • *DAMPING_GLOBAL
    • *DAMPING_PART_STIFFNESS
    • *SET_BEAM_ADD
    • *SET_DISCRETE
    • *SET_DISCRETE_ADD
    • *SET_NODE_ADD_ADVANCED
    • *SET_SEGMENT
    • *SET_SHELL_ADD

Enhancements

Force vector output
  • /ANIM/VECT/FINT also shows internal forces on the secondary nodes of rigid bodies.
  • /ANIM/VECT/FREAC has been generalized to all kinematic conditions.
  • /ANIM/VECT/FEXT now shows external loadings only (/CLOAD, /PLOAD, /GRAV, /MONVOL, …) and no longer includes the reaction forces due to kinematic conditions.
  • Reaction forces are now available in /TH/NODE for secondary nodes of a rigid body (for example, REACX, REACY, ...).
Tied contact (/INTER/TYPE2)
  • Improvement of secondary node projection on 3 noded shell surfaces.
Penalty contact
  • /INTER/TYPE24: New flag to define a time duration to remove initial interference (Inacti=-1).
  • /INTER/TYP25:
    • Improvement of the contact interface behavior with Inacti=5. Force was evident at Time=0 for some specific models.
    • Improvement of the contact interface behavior for some specific cases with boundary conditions (/BCS).
  • /INTER/TYPE7 and /INTER/TYP25: Starter computation time reduction in cases where mesh size is smaller than gap value.
Materials
  • /MAT/LAW0 (VOID): Void material is now compatible with beam and truss elements.
  • /MAT/LAW1 (ELAST): Improvement of the computation time for solid elements with Ismstr=10.
  • /MAT/LAW108: The density of the material can be null and the inertia in the spring property /PROP/TYPE23 (SPR_MAT) can be null
  • /MAT/LAW44:
    • The values a, b and n are not used for the computation of the yield stress value when VP ≠1 and a yield curve is defined.
    • Strain rate filtering parameters are automatically defined by Radioss for VP=1.
    • Automatic strain rate cut off frequency value is defined by Radioss when the input value is zero.
Monitored volume
  • /MONVOL/GAS: Improvement of computation performance when the simple gas monitored volume is used in large models using HMPP calculation.
  • /MONVOL/FVMBAG1:
    • Correction of automatic meshing (kmesh > 0) for airbags defined with 4 noded shell elements. The Starter was failing with different error messages for specific models.
    • The option Ittf = 3 was not working as expected for airbags meshed with kmesh = 14.
Shell property and default shell card
  • /PROP/TYPE51: Improvement of the memory usage for the composite shell property in the Radioss Starter.
  • /PLY: New Starter error message in case material is not defined for a ply. Without material the composite part behaves incorrectly.
Solid property (/PROP/SOLID)
  • Stability improvements for models with /TETRA10 Itetra10=2 elements, double precision, HMPP and /PARITH/OFF option.
  • Improvement of solid element behavior after material failure. Some computation was still done.
  • Improvement of element stability for degenerated brick elements for some specific mesh patterns.
Subdomain (/SUBDOMAIN)
  • /INTER/SUB is now compatible with the subdomain approach.
ALE/FSI features
  • Improvement of pressure mapping and volume fraction mapping with /MAT/LAW51.
  • Development of /PARITH/ON and MPI with /MAT/LAW151.
LS-DYNA reader
  • An error is now printed in case a keyword is not supported.
  • *CONTROL_TIMESTEP: TSSFAC is now set as time step scale factor in /DT/NODA/CST card.
  • *DATABASE_SWFORC: Spotwelds are added in the time history /TH/SPRING or /TH/BRIC.
  • *MAT_020: Improvement of the reporting for the mapped information.
  • *MAT_123: Improvement for the mapping of this material law to Radioss material law.
  • *SET_NODE: The option COLUMN is now supported.
  • *SET_PART: All input options for sets of parts are now supported.
  • Mass and inertia are no longer added for the spring materials *MAT_S01, *MAT_S02, *MAT_S03, *MAT_S04, *MAT_S05, *MAT_S06 and *MAT_S08.
Radioss reader
  • /STATE: Improved error message in case the referenced part does not exist in the model or card format is not correct.
  • Improvement of the warning message (#666) for solid element connectivity to have a smaller element list.
Madymo coupling
  • Update of the coupling library with Madymo 2020.1
  • Updated coupling is available for Radioss SPMD/HMPP with Intel® MPI
  • Previous coupling with Platform MPI is removed

Resolved Issues

LS-DYNA reader
  • *BOUNDARY_PRESCRIBED_MOTION_SET: Input issue correction for VAD=1.
  • *CONSTRAINED_RIGID_BODIES: Correction of reading issue when several rigid bodies are defined in a model.
  • *SECTION_SHELL: The parameter SHRF is now ignored for the model mapping. The default value is always used for Radioss computation (best setting).
  • *CONSTRAINED_SPOTWELD: Mapping improvement when several elements are specified inside the same card.
  • *CONTACT_AUTOMATIC_SINGLE_SURFACE: Mapping correction if set is empty. The entire model was not selected.
  • *DATABASE_RWFORC: Rigid walls are now output in the time history file.
  • *DEFINE_COORDINATE_SYSTEM: The title is now correctly read.
  • *INITIAL_VELOCITY: Correction of the initial velocity setting with rigid bodies and the different possible options for the initial velocity treatment of rigid bodies.
  • *SET: Reading error correction of the set when there are several lines and the line is not completely filled.
  • *SET_PART_ADD: Correction of the behavior where a negative sign is defined on the set ID. The Starter no longer fails.
  • Correction of ID conflict between created /SKEW and /FRAME .
  • Correction of ID conflict between sets with the same ID but different type.
Radioss reader
  • //SUBMODEL: The local coordinate system (/SKEW) created to follow the motion of the submodel was not applied on the imposed motion (/IMPVEL, /IMPDISP or /IMPACC) from version 2021.
  • /FAIL/TBUTCHER: Correction of reading issue. Radioss Starter no longer shows error for specific input.
  • /FAIL/TENSSTRAIN: Improvement of the error message in case of wrong input in the /FAIL/TENSSTRAIN card (if ε t 2 < ε t 1 ).
  • /INTER/TYPE12: This contact interface was not read in version 2021.
  • /INTER/TYPE19: Correction of Radioss Starter numbering issue for specific models from version 2021.
  • /INTER/TYPE21: Correction to Units of friction coefficients for different laws, STFAC, KTHE, FRAD and DRAD.
  • /INTER/TYPE24: Units of friction coefficients for different friction laws is corrected.
  • /MONVOL/FVMBAG1: Correction of card input with porous surface.
Resolution issues
  • /ADYREL: Improvement of the damping value computation. Model was diverging because the damping was too high.
  • /FAIL/ALTER: Correction of the failure behavior with Irate=1. The computation was failing in version 2021.
  • /FAIL/GURSON: Correction for the single precision version.
  • /FAIL/JOHNSON: Correction of SPMD issue in Starter or Engine with failure model and Ixfem=1 applied on a solid part.
  • /H3D output:
    • Correction of the output format for 3D stress tensors. The von Mises value and other scalars were computed with strain data for some specific setting.
    • Deleted spring elements were not set in the eroded element pool.
    • The contact force and pressure value displayed was not correct in the H3D output.
  • /INIVOL: Correction of phase initialization for specific models. The initialization was not correct since version 2020.1.
  • /LOAD/CENTRI: Correction of the external work computation in cases where a centrifugal load is applied on a rigid body (/RBODY) secondary node only (whether it is applied on the main node or not).
  • /MAT/LAW24: The output for /ANIM/BRICK/TENS/STRAIN was overwritten by /ANIM/BRICK/TENS/EPSP (specific output for concrete material LAW24 with Icap=2).
  • /MAT/LAW36:
    • Correction of the internal energy computation after erosion of quadratic tetrahedron elements (/TETRA10).
    • Improvement of the material behavior with VP=1 for specific loadcases (blow molding analysis).
  • /MAT/LAW42: Correction of SH3N shell stability with Ogden materials. Specific models were diverging (non-expected element failure).
  • /MAT/LAW69: Solid behavior improvement with HEPH formulation (Isolid=24). The model was diverging.
  • /MAT/LAW70: Correction of interpolation error where there is only 1 point in the curve.
  • /MAT/LAW80: Correction of unstable behavior and non-physical plastic strain output for shell formulations Ishell=24 or Ishell=1.
  • /MAT/LAW88: Correction of memory allocation in the Starter (possible segmentation violation).
  • /PROP/TSH_*: Correction of tensor output (stress, strain) for thick-shell elements for both the animation and native H3D outputs.
  • /RBE3:
    • Improvement of the force distribution in case the reference node is far from the independent nodes.
    • Correction of RBE3 behavior with SPMD/HMPP version. Node position is correctly computed for specific models with many interconnected RBE3.
    • Correction of mass added when dependent node is far away from the independent nodes.
  • /SET/GENERAL:
    • Correction for the SET of SET. 3 nodes shell elements (/SH3N) were missing.
    • Memory allocation improvement.
    • Sets defined with /SET_D are taken into account after the key option, ALL.
  • /STATE/NODE/VEL: All nodes were output regardless of the /PART selection in /STATE/DT.
  • /SUBDOMAIN: Local coordinate system skew_ID of spring property is correctly transferred to the sub-domain.
  • /SURF/DSURF: Correction of Starter issue with specific surface definition. The Starter no longer hangs.
  • /PARITH/ON: The external forces from /CLOAD, /PLOAD or /LOAD/PFLUID are correctly released after de-activation by sensor.
  • The memory usage value reported in Engine listing file is corrected on SPMD win64 version.