Altair Radioss 2025 Release Notes

Highlights

  • Continuous development for the LS-DYNA format reader.
  • First option /FUNCT_PYTHON where Python script can define function values.
  • Option to control solid element distortion (Icontrol=1) to improve solid element stability and avoid negative volumes.
  • Improvement of rigid body (/RBODY) stability. This modification may lead to some small differences from previous versions.
  • New table sorting feature for large tables.

New Features

LS-DYNA Format Reader
Additional LS-DYNA format reading capabilities
  • *CONTROL_HOURGLASS
  • *INITIAL_STRESS_SOLID
  • *MAT_ADD_THERMAL_EXPANSION
  • *MAT_005 (SOIL_AND_FOAM)
  • *MAT_073 (LOW_DENSITY_VISCOUS_FOAM)
  • *MAT_111 (JOHNSON_HOLMQUIST_CONCRETE)
  • *MAT_169 (ARUP_ADHESIVE)
  • *MAT_183 (MAT_SIMPLIFIED_RUBBER_WITH_DAMAGE)
Loadcase and Contact Interface
  • /DFS/DETPOINT/SET: option to define detonation points applied on a set of nodes (/SET or /GRNOD).
  • /FUNCT_PYTHON: new possibility to get the current time and time step in a Python script.
  • State output (/STATE/SPHCEL/FULL) and input (/INISPHCEL/FULL) to initialize Smooth Particle Hydrodynamics.
Material and Failure Models
  • /MAT/LAW169 (ARUP_ADHESIVE): new material law for adhesive material law to simulate adhesive with ability to take into account both cohesive and damage behavior, tailored for materials that exhibit a mix of elastic, plastic, and brittle failure characteristics (for solids).

Enhancements

LS-DYNA Format Reader
  • *DATABASE_HISTORY_{OPTION}_SET: keyword reading improvement for all input types.
  • *DATABASE_HISTORY_BEAM: specific beam element type was missing in the time history file.
  • *DEFINE_COORDINATE_NODES: reading improvement and corrections
  • *MAT_002 (ORTHOTROPIC_ELASTIC): this material is now mapped to /MATLAW93 for better accuracy.
  • *MAT_009 (NULL): null material *MAT_NULL with *EOS was not correctly read.
  • *MAT_077_O (OGDEN_RUBBER): the number of material parameter pairs is extended from 5 to 8.
  • *MAT_181 (SIMPLIFIED_RUBBER/FOAM): improvement of the material reading and mapping.
  • *SECTION_SHELL: reading improvement in case NIP > 10.
  • *SET_PART_ADD: correction of set reading in case a set type has the same identifier.
  • *SET_PART_LIST: nodes from SPH elements were not included in the set.
Loadcases and Contact Interfaces
  • /CLOAD, /PLOAD: the concentrated load and pressure load can be a function of node displacement or velocity.
  • /INIVEL/AXIS, /INIVEL, /INIVEL/FVM: new option to define the starting time; from defined value or sensor (/SENSOR).
  • /INIVOL:
    • New option ICUMU = -1 defines subtractive input of volume fraction. The current surface is used to fill the element and if sum of ratio is greater than 1, then it is subtracted from the previous initial volume setting.
    • After all execution of initial volume options, the unoccupied sub-volume is now automatically filled with the prevalent phase (VFRAC > 0.9). It was filled with phase 1 in the previous version.
    • Compatible with 2D solid elements for axisymmetric and plane strain analysis.
  • /INTER/TYPE1:
    • Error message added in the Starter in case of incompatible boundary condition in the Starter.
    • Additional check in the Starter for the tied FSI contact to verify if the main side is defined in Lagrangian domain and the secondary side in the ALE domain.
    • Global improvement in the search algorithm of the fluid versus structure tied contact
  • /INTER/TYPE2:
    • Modification of the output to consider the loading direction and display positive value in tensile and negative value in compression.
    • Some corrections have also been made for the contact force outputs. The results will be different from the previous version.
  • /INTER/TYPE24, /INTER/TYPE25:
    • New warning message in case INACTI flag is set to a non-expected value. The flag INACTI is reset to default value.
    • Correction of Starter segmentation violation when /INTER/SUB is used.
  • /INTER/TYPE7, /INTER/TYPE11:
    • Improvement of the behavior of Irem_gap=2 with Igap=3. Some contacts were not correctly removed.
Material and Failure Models
  • /FAIL: failure model ID of the deleted/ruptured element is now printed in the Engine output file.
  • /FAIL/FLD: new failure model based on Forming Limit Diagram which handles nonlinear strain paths. This failure model is used in sheet metal forming.
  • /FAIL/GENE1: improvement of the compatibility between parameter dtmin and constant nodal time step (/DT/NODA/CST).
  • /FAIL/JOHNSON: new failure options Ifail_so=3 and Ifail_so=4 for solid element dedicated for ballistic or high-speed impact applications.
  • /MAT/LAW1, /MAT/LAW42, /MAT/LAW62, /MAT/LAW69: increased contact stiffness in case the element distortion control is activated.
  • /MAT/LAW2 is now compatible with all Equation of State (/EOS).
  • /MAT/LAW36 is now compatible with Equation of State (/EOS).
  • /MAT/LAW42: new capability to define up to 10 shear hyper elastic moduli and material exponents.
  • /VISC: viscosity models can now be used for any material laws compatible with shell elements.
Element and Properties
  • /PROP/SOLID, /PROP/SO_ORTH, /DEF_SOLID: new flag Icontrol=1 to activate the solid element distortion control and internal contact in the solid element to avoid negative volume.
Animations and Time History Output
  • /TH/SURF: new output for the pressure, mass flow and fluid velocity through a surface coming from Element Boundary Condition /EBCS/INLET, /EBCS/FLUXOUT, /EBCS/NRF and internal surface of ALE/EULER domain defined with /SURF/SEG.
Starter and Engine
  • Update and improvement of the stacksize setting.
  • New option -python to explicitly authorize usage of Python script in Radioss.
Verification Models
  • New verification problem for failure model /FAIL/BIQUAD (RD-V: 0710)
  • Update to the fabric material verification problem (RD-V: 0230)

Resolved Issues

LS-DYNA Input Format
  • *CONSTRAINED_INTERPOLATION: element stability issue with large time step.
  • *CONTACT: mapping for the parameters SST and MST (optional contact thickness).
  • *CONTACT_AUTOMATIC: reading correction if SOFT=2.
  • *DEFINE_COORDINATE_NODES: reading correction if dir=Y. The coordinate system was not well oriented.
  • *DEFINE_TRANSFORMATION: reading improvement if the transformation type is not recognized or valid.
  • *ELEMENT_DISCRETE: reader improvement if there is no local coordinate system (*DEFINE_SD_ORIENTATION) defined in the discrete element.
  • *INITIAL_VELOCITY: node set that are exempted from the initial velocities (Exset_ID) is now correctly read.
  • *MAT_015 (JOHNSON_COOK): reading correction if E=0.
  • *SET: reading correction for the empty set (*SET).
Loadcases and Contact Interfaces
  • /ALE/GRID/FLOW-TRACKING: behavior improvement in case of rotational transformation (/TRANSFORM/ROT).
  • /ALE/MAT, /EULER/MAT: correction of communication issue for ALE or Euler material formulation with SPMD; HMPP version and for specific model.
  • /EBCS/INLET: compatible with //SUBMODEL
  • /INIVOL: incorrect initialization with specific model with /MAT/LAW151 and linear tetrahedron (/TETRA4)
  • /INTER/TYPE1: ALE tied interface is now compatible with 2D analysis.
  • /INTER/TYPE21: correction of contact interface checking, incorrect minimum contact gap value was printed in the Starter output file.
  • /INTER/TYPE24, /INTER/TYPE25: memory allocation issue which leads to a segmentation fault in the Engine restart when the output option /H3D/NODA/CSE_FRIC was used.
  • /INTER: improvements and corrections of the contact interface surface update in case of element failure.
  • /RBODY: stability improvement of the rigid body with 2 secondary nodes in case of high rotational velocity.
  • /RETRACTOR/SPRING:
    • Improvement of the seatbelt behavior if only fct_ID1 is defined with a null or negative slope.
    • New error message if only fct_ID1 and fct_D2 are defined and have a null or negative slope.
  • /RWALL: memory allocation issue.
  • /SECT/PARAL:
    • Reading for /SECT/PARAL with specific model.
    • Correction of warning message for the section forces when the preload option (/PRELOAD) is used in the model.
  • /SET/GENERAL:
    • Surface build corrections and improvement.
    • Correction for the 2D surface defined with segments.
    • Reading improvement for the SPH elements.
    • One attribute was missing for the set of nodes with the key NODENS.
    • Issue with surface building for 3 node shell elements (/SH3N) with adaptive meshing (/ADMESH).
    • The nodes from SPH defined by parts were not correctly extracted from the general set.
    • Reading correction for the set used in the drawbeads contact /INTER/TYPE8.
  • /SKEW, /FRAME: reading correction in case the reference direction is written with a lower-case letter.
  • /SLIPRING/SHELL: correction of animation file output for specific model computed with SPMD/HMPP version.
Material and Failure Models
  • /FAIL/FRACTAL_DAMAGE: initialization may be wrong with SPMD/HMPP version in win64 platform.
  • /MAT/LAW2: improvement of the thermal behavior for the elastic-plastic material laws.
  • /MAT/LAW25: correction of wrong behavior for tensile plastic damage in direction 1 with solid elements
  • /MAT/LAW83: strain rate was not correctly computed for Fsmooth=1 and specific model. Strain rate value was also not output in solid element time history.
  • /MATLAW58, /MAT/LAW19: reading improvement for the single precision version.
  • /MAT/LAW62: stability improvement for specific loadcase.
  • /MAT/LAW76: correction of Radioss Engine for specific model.
  • /NONLOCAL/MAT:
    • Improvement of the post-failure behavior of non-local elements.
    • Correction of parallel arithmetic behavior with non-local failure formulation.
Element and Properties
  • /PROP/TYPE29 (USER): memory allocation correction for the UVAR buffer for the user property interface.
  • /PROP/TYPE3 (BEAM):
    • Correction of memory allocation issue if there is a failure model defined for the material used in the beam.
    • Starter no longer fails when material with failure model (/FAIL) is defined on the material set on a beam.
    .
  • /PROP/TYPE45 (KJOINT2):
    • The joint main direction is defined from node N1 and N2 in case Skew_ID1 and Skew_ID2 are defined.
    • This modification may lead to some results differences compared to previous versions from specific models.
  • /PROP/TYPE1 (SHELL), /PROP/TYPE9 (SH_ORTH), /PROP/TYPE10 (SH_COMP): flag Ipos is added in all shell properties to model shell offset from the mid plane.
Animations and Time History Output
  • /ANIM/BRICK/TENS, /H3D/SOLID/TENS: all integration points are now output in the animation file (/ANIM) and the native .h3d file (/HD3) for the linear tetrahedron with Itetra4=1.
  • /H3D/BEAM/TENS/STRESS, /H3D/BEAM/TENS/STRAIN: memory allocation correction.
  • /H3D/QUAD: correction of vector output for the 2D solid element.
  • /H3D/SHELL corrections:
    • "Erosion status (s)" output.
    • /H3D/SHELL/DAMA output for /MAT/LAW25.
    • /H3D/SHELL/TENS/STRESS output. Some unexpected PLY was output.
    • /H3D/SHELL/FAIL output.
    • /H3D/SHELL/FAILURE/* for specific case.
  • /H3D/SPRING/FORC, /H3D/BEAM/FORC, /H3D/TRUSS/FORC: the 1D element force and moment writing in the .h3d file is now readable.
  • /H3D/NODA/GPS/TMAX, /H3D/NODA/GPSTRAIN/TMAX: maximum stress values could decrease according to time for specific models.
  • /TFILE, /ABF: time history data for the parts were missing in case a non-existing part is set in the /TH/PART card.
Starter and Engine
  • Radioss Starter no longer fails with the option -output=[path] if the length of Starter output file name with the full path is longer than 100 characters.
  • /DT/NODA/CST: parameter initial_mass_ratio is now correctly considered for multiple runs.