What's New

View new features for Radioss 2024.

Altair Radioss 2024 Release Notes


  • Continuous development for the LS-DYNA format input.
  • Several modifications and improvements for the composite properties with respect to orthotropic angle definition (angle defined in the shell element, flag def_orth removed, new flag values IP=25 and 26).
  • Many other enhancements in the crash and fluid analysis features, including material & failure, contacts, SPH and output.

New Features

Starter Reader
  • New LS-DYNA format reading capability:
    • *MAT_030 (SHAPE_MEMORY)
    • *MAT_187 (SAMP-1)
Animation and Time History Output
  • /H3D/SOLID/TENS/STRAIN/OUTER_AVERAGE: new result output to display outer average strain tensor strain value.
  • /H3D/SHELL/HC_DSSE_Z, /H3D/SHELL/HC_DSSE_F: new output to display the failure zone factor and damage factor indicator.
  • /H3D/ELEM/VECT/ACC: fluid acceleration can be output in .h3d file for cell centroids (/MAT/LAW151).
Materials and Failure Models
  • /FAIL/ORTHENERG: new orthotropic failure criterion based on fracture energy.
Loadcase, Constraints and Contact Interfaces
  • /DAMP/VREL: new Rayleigh damping computed from the average velocity of the node set or rigid body main node motion.
Engine Control File
  • New option to reset the status of all or selected sensors at the beginning of the run.


LS-DYNA Format Reader
  • The option BETA is now supported in *ELEMENT_SHELL.
  • *MAT_058 (LAMINATED_COMPOSITE_FABRIC): reading and mapping improvement.
  • *MAT_071 (CABLE_DISCRETE_BEAM): improvement of the mapping to /MAT/LAW113 with Ileng=1.
  • The material *MAT_074 (ELASTIC_SPRING_DISCRETE_BEAM) is now mapped to /MAT/LAW113 for a more accurate result.
  • *MAT_NULL: reading enhancement for null material reading when *EOS is defined on the solid element part.
  • *SECTION_SHELL: reading improvement for the shell element linked to composite materials.
  • Parallel arithmetic method is turned to off by default for the LS-DYNA format input.
  • The main node of the rigid body coming from *MAT_RIGID is now positioned in the C.O.G of the secondary nodes (only if the position is not explicitly specified).
  • *DEFINE_SD_ORIENTATION: The stiffness direction was not correctly read when the option TITLE is defined.
Elements and Properties
  • /PROP/SPH:
    • The viscosity effect is removed in tension behavior to reduce its effect on the SPH behavior.
    • The viscous parameters qa and qb are renamed to Beta and Alpha to be more consistent with the literature.
  • /PROP/TYPE16: element behavior improvement in case failure model (/FAIL) is linked to the component.
  • The angle defined in the shell element is now added to the orthotropic angle value in any case in the composite property and stack.
  • The flag def_orth defined on the ply (/PROP/TYPE19, /PLY) is removed, phi_s angle on elements is always considered, and used in conjunction with the flag IP on the stack definition. For data in older input versions that used def_orth = 1, the previous versions reference frame behavior can be replaced with the flag IP=26 defined in the composite property or stack.
  • New flag IP=25 to define the first direction of an orthotropic material according to the azimuthal direction of a cylindrical coordinate system.
  • New generic check for the compatibility with material, element, and properties.
Materials and Failure Models
    • Default value for parameter S-Flag is changed from 1 (no minimum) to 2 (plain strain is global minimum) to avoid numerical issue and wrong failure behavior.
    • New option to create stress softening before element deletion.
    • This failure model can be used for beam elements (/PROP/TYPE3 and /PROP/TYPE18).
  • /FAIL/GENE1: VOLFRAC is no longer active for shell elements.
  • /FAIL/HC_DSSE: new flag Ifail_sh=4 to compute the failure criterion but without element failure or stress reduction.
  • /FAIL/JOHNSON: this failure model can be used for beam elements (/PROP/TYPE3 and /PROP/TYPE18).
  • /FAIL/TAB2: Lode parameter can be used for the mesh dependency scaling with IREG=2.
  • /MAT/LAW11 (BOUND): new error message in case the material is associated with an incompatible material law.
  • /MAT/LAW70: new curve smoothing and de-intersection for tabulated material law. The modified curves are printed in the Starter output file.
  • /MAT/LAW76: improvement of the hardening model.
Loadcase, Constraints and Contact Interfaces
  • /INTER/TYPE24:
    • Improvement of the contact stiffness definition for the pressfit option (Inacti=-1) to better solve the initial penetrations.
    • New option Inacti=-2 is added with high stiffness.
  • /INTER/TYPE25: improvement of the contact behavior. Radioss Engine was hanging in the contact sorting for specific model.
  • /MONVOL/FVMBAG1: the options Kmesh=2 and 4 are removed from Radioss. They are automatically replaced by Kmesh=12 or 14. Differences in the results are expected.
  • New error message in the Starter and Engine in case the nodes defined in the shell slipring element (/SLIPRING/SHELL) are not defined in a rigid body.
Animation and Time History Output
  • /H3D/ELEM/DAMG: the options PLY and LAYER are now available for the coupled damage output.
  • /H3D/ELEM/EINTV: internal energy per volume unit is now available for shell and beam elements.
  • /H3D/ELEM/VECT/CONT: contact reaction forces can be post-treated on the fluid side in .h3d file for the multi-fluid material law /MAT/LAW151 and the FSI contact interface /INTER/TYPE18.
Engine Performances and Scalability
  • Compression library update with Zlib for the option /ANIM/GZIP and /STATE/STR_FILE.
  • Improvement of the computation speed for composite elements /PROP/TYPE51.
  • Improvement of option -licwait behavior for specific setting (HHWU managed licenses).

Resolved Issues

LS-DYNA Format Reader
    • Reading improvement for different types of joint combinations.
    • Reading correction in case stiffness is not defined in all non-blocked degree of freedom.
  • *DEFINE_TABLE_2D: improvement of the table and function reading. Table identifier was not correctly defined for specific cases.
  • *ELEMENT_SEATBELT_SLIPRING: reading correction in case the keyword is defined in several includes.
  • *INITIAL_FOAM_REFERENCE_GEOMETRY: improvement of the reading speed for the reference geometry.
  • *INITIAL_STRAIN_SHELL, *INITIAL_STRESS_SHELL_{OPTION}: reading improvement for the elastic material.
  • *MAT_ADD_EROSION: improvement of the failure model mapping.
  • *PART_COMPOSITE: correction for the reading of the parameter NLOC.
  • *SECTION_SEATBELT: correction of the entity reading in case there are several seatbelts under the same keyword.
  • Improvement of the LS-DYNA reader speed in case there is a very large number of sets.
Elements and Properties
  • /DRAPE: correction of memory allocation issue for specific model.
  • /PROP/SHELL: initial state for shell element (INISHE) could not be read for part with elastic material (/MAT/LAW1) without global integration (N=0 in the /PROP/SHELL).
  • /PROP/TYPE14: correction of the density output after the element deletion.
  • /PROP/TYPE17: correction of Starter initialization issue when composite /PROP/TYPE51 or /STACK was defined in the same model.
    • Correction of the element behavior with shell offset (Ipos > 0) and specific property where the thickness is bigger than the mesh size.
    • Improvement of the time step estimation for composite shell elements with surface offset (Ipos > 0). The time step was too small.
Materials and Failure Models
  • /EOS: correction of the reader when the Equation of State is encrypted.
  • /FAIL/GENE1:
    • Correction of initialization issue when initial state (INISHE) is defined for shell elements.
    • Behavior improvement in case there are no parameters in the failure model. The failure model is ignored, and a warning message is printed in the Starter output file.
  • /FAIL/TAB1: correction of the failure model reading.
  • /MAT/LAW1: correction of the shell stress and strain tensor output in the animation files for the upper and lower surfaces.
  • /MAT/LAW12: plastic work (/H3D/SOLID/WPLA) and specific energy (/ANIM/ELEM/ENER) are no longer missing in the .h3d output file.
  • /MAT/LAW57: correction of the equivalent stress computation for the output (/ANIM/ELEM/SIGEQ, /H3D/ELEM/SIGEQ).
  • /MAT/LAW58: improvement of the shell behavior with QEPH formulation (Ishell=24).
  • /MAT/LAW95: The stress calculation is corrected for the polynomial hyperelastic energy function. A new flag Iform to fit strain energy density formulation.
  • /MAT/LAW109: correction of the strain rate dependency with failure criteria.
  • /MAT/LAW112: initial state defined in /INIBRI cards were not correctly set in the elements.
Loadcase, Constraints and Contact Interfaces
  • /INTER: correction of the contact surface orientation of the linear tetrahedron element.
  • /INTER/TYPE18: improvement of the contact interface with /MAT/LAW151 and specific model.
  • /INTER/TYPE24: correction of potential issue in the sliding behavior.
  • /INTER/TYPE25: correction of the memory allocation for specific model.
  • /LOAD/PBLAST: warning message for /LOAD/PBLAST is now displayed in correct unit system.
  • /SENSOR/ENERGY: correction of time delay behavior for specific model.
Animation and Time History Output
  • /H3D: correction of output issue for the tensor of the solid element requested on a set of parts.
  • /H3D/QUAD/TENS/DAMA: memory allocation correction for Isolid=17.
  • /H3D/SHELL/PHI/PLY=ALL, /ANIM/SHELL/IDPLY/PHI/ALL: correction of the ply angle display in the .h3d or animation file for specific model with composite shell elements (/PCOMPP/STACK, /PLY).

Deprecated Options

  • Subcycling options are removed from Radioss.
  • FSI contact interface /INTER/TYPE22 is obsolete option.