Altair Radioss 2025.1 Release Notes

New Features

New LS-DYNA format reading capabilities
  • *CONTACT_AUTOMATIC_BEAMS_TO_SURFACE
  • *DATABASE_PLLYOUT
  • *DATABASE_TPRINT
  • *DEFINE_CURVE_SMOOTH
  • *DEFINE_HEX_SPOTWELD_ASSEMBLY
  • *ELEMENT_SEATBELT_RETRACTOR
  • *ELEMENT_SEATBELT_PRETENSIONER
  • *ELEMENT_SEATBELT_SENSOR
  • *MAT_122 (HILL_3R)
  • *MAT_ADD_DAMAGE_GISSMO
Loadcases and contact interfaces
  • /DAMP/FREQUENCY_RANGE: option to define a constant Rayleigh damping over a range of frequencies on sets of shell and solid element deformation.
  • /INTER/TYPE2: add surface to surface input treatment in the tied contact.
  • /SENSOR/PYTHON: new sensor using Python script.
  • /VISC/PLAS: Frequency independent viscous model with elastic stiffness G and stress limit SIGF parameters.
Material and Failure models
  • New compaction equation of state /EOS/COMPACTION2 similar to that defined in /MAT/LAW21 (DPRAG).
  • New modes output in the animation output (/H3D/SOLID/FAILURE, /H3D/SHELL/FAILURE) for the following failure models:
    • /FAIL/SPALLING
    • /FAIL/FLD
    • /FAIL/ORTHSTRAIN
  • New parameter to model the compacted behavior in the honeycomb material /MAT/LAW50 (VISC_HONEY) with isotropic elastic-plastic material.
Element and properties
  • Beam orientation can be defined with a vector in the beam element (/BEAM).
Animations and time history output
  • /H3D/SPH/NEIGHBOURS in .h3d file to display the number of neighbors for SPH elements with property /PROP/TYPE24 (SPH).
Starter and Engine
  • Engine control option /IMPL/MUMPS/AUTOCORE to switch automatically to out of core memory model when there is not enough memory available (same as /IMPL/MUMPS/OUTCORE).

Enhancements

LS-DYNA format reader
  • New error message in case function LCSS is defined in the material but does not exist in the model.
  • *AIRBAG_LINEAR_FLUID: reading improvement in case P_MAX and P_MAX_ID are not defined. Maximum pressure was set to 0.0.
  • *CONTACT: the option _TITLE is read like the option_ID.
  • *CONTACT_INTERIOR: contact interior is now activating the element distortion control flag (Icontrol=1) in the solid property. Result differences are expected for specific case from the previous Radioss version.
  • *CONTROL_HOURGLASS and *HOURGLASS: Improvement of hourglass control reading.
  • *CONTROL_UNITS: new error message in case the unit card is not defined in the model, and it is mandatory for entity mapping.
  • *DEFINE_VECTOR: the vector can now be defined in the local coordinate system skew_ID.
  • *DEFINE_VECTOR and *DEFINE_VECTOR_NODE: the option _TITLE is now supported.
  • *INITIAL_VELOCITY_GENERATION: improvement of local coordinate reading.
  • *LOAD_BODY: Option VX, VY, VZ and VECTOR are now read by Radioss Starter.
  • *MAT_024 (PIECEWISE_LINEAR_PLASTICITY): reading improvement in case of VP=1 with LOG_INTERPOLATION option.
  • *MAT_077_O (OGDEN_RUBBER):
    • Frequency independent damping (G; SIGF) is now read.
    • Better mapping of the LS-DYNA input to the Radioss solution.
  • *MAT_083 (FU_CHANG_FOAM): the parameter TFLAG is better considered.
  • *MAT_119 (GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM): reading improvement in case parameter SCOOR=2, or -2 is defined in the *SECTION_BEAM card. The material is now mapped to /MAT/LAW113.
Loadcases and contact interfaces
  • New Starter error message in case an Element Boundary Condition (/EBCS) is applied on a Lagrangian element.
  • /INIVEL/AXIS, /INIVEL, /INIVEL/FVM: new option to define the starting time from defined value or sensor (/SENSOR).
  • /INIVOL:
    • Sorted node group (/GRNODE/NODENS) can be used for the initial volume definition in 2D analysis.
    • Improvement of the Starter computation time for the initial volume computation for 2D analysis when the cut surface is defined with segments.
    • After execution of all /INIVOL options; the unoccupied sub-volume is now automatically filled with the prevalent phase (FILL_RATIO>0.9). It was filled with phase 1 in the previous version.
  • Reference metric (/XREF, /EREF, /REFSTA) can be used for solid elements and elastic material (/MAT/LAW1).
Material and Failure models
  • External work from the equation of state /EOS/GRUNEISEN is now included in the total external work time history output.
  • /EOS/COMPACTION: new check for the unloading modulus to avoid unrealistic behavior and model instability.
  • /EOS/GRUNEISEN: new pressure shift (PSH) and initial pressure (P0) parameters.
  • /FAIL/TAB2: new parameter VOLFRAC for damaged volume fraction to be reached before the element is deleted (fully-integrated and higher order solid elements only).
  • /MAT/LAW51 (MULTIMAT): material /MAT/LAW2 can be added in the multi material model (Iform=12).
  • /MAT/LAW57 (BARLAT3): the material law has been completely revised with new and better algorithms and is much faster. Some small differences in the results are expected from previous versions.
  • /MAT/LAW81:
    • Scale factor function for the cohesion, ‘c’ can be dependent on the volumetric plastic strain parameter ε v p or deviatoric plastic strain ε e q p using a new flag.
    • Correction of the von Mises stress output for specific model and loadcase.
    • The equivalent stress is not available in the animation files.
  • /MAT/LAW87 (BARLAT2000):
    • New option to enable simple kinematic hardening (Prager-Ziegler model).
    • Yield stress defined from input curves.
  • /MAT/LAW88:
    • The error message when compression strain is defined with a value smaller than -1 is changed to warning.
    • Enhancement for the unloading behavior and definition with the flag Tension for an improved and more stable behavior.
  • /MAT/LAW126 (JOHNSON_HOLMQUIST_CONCRETE): new IFAILSO parameter to control post-failure behavior.
Element and properties
  • The following failure models can be used for beam elements (/PROP/TYPE3, /PROP/TYPE18):
    • /FAIL/GENE1
    • /FAIL/INIEVO
    • /FAIL/TAB2
    • /FAIL/VISUAL
  • New parameter FAILIP in the following failure models to select the ratio of number of integration points for element deletion of the integrated beam element (/PROP/TYPE18):
    • /FAIL/BIQUAD
    • /FAIL/COCKROFT
    • /FAIL/GENE1
    • /FAIL/ENERGY
    • /FAIL/INIEVO
    • /FAIL/JOHNSON
    • /FAIL/TAB2
    • /FAIL/TENSSTRAIN
  • /PROP/TYPE14 (SOLID):
    • Element distortion control enhancement to reduce non-physical element deformation under specific loading.
    • Behavior improvement of the solid formulation Isolid=5 by adding damping for the hourglass modes and in case of element deletion.
    • Correction of viscous parameters qa and qb for improved stability and formulation consistency for any solid element. The results may be slightly different from previous versions.
  • /PROP/TYPE20 (TSHELL): the stress and strain tensors were missing for some integration points in the .h3d file for components with elastic material (/MAT/LAW1).
  • New flag Icontrol to activate the element distortion control for each part in the thick-shell properties (/PROP/TYPE20, /PROP/TYPE21, /PROP/TYPE22).
Animations and time history output
  • /H3D/ELEM/ORTHD: the keyword "THETA" is replaced by "TETA" to be compatible with HyperView (for the system review panel).
  • Volumetric strain can be output in the animation file (/H3D/SOLID/VSTRAIN, /ANIM/BRIC/VSTRAIN) and time history (/TH/BRIC) for each phase of the multi-materials /MAT/LAW20, /MAT/LAW37, /MAT/LAW51 and /MAT/LAW151.
  • Warning message instead of an error message in case an entity is defined in the time history output (/TH/…) but does not exist in the model.
  • Plastic work WPLA from composite material /MAT/LAW25 can be output in time history for each solid element (/TH/BRIC).
  • All entities are automatically defined in the time history output with the Obj_ID=0 for:
    • /TH/ACCEL
    • /TH/GAUGE
    • /TH/INTER
    • /TH/MONVOL
    • /TH/PART
    • /TH/RBODY
    • /TH/SECTIO
    • /TH/SENSOR
    • /TH/SUBS
  • /TH/SURF:
    • New possibility to output pressure, mass-flow and fluid velocity through a surface of /EBCS/INLET, /EBCS/FLUXOUT, /EBCS/NRF and internal surface of ALE/EULER domain defined with /SURF/SEG.
    • The pressure is now averaged proportionally to the surface area of the element. It gives better pressure estimation in case of non-uniform mesh.
Starter and Engine
  • /MADYMO/EXFEM: composite properties /PROP/TYPE51, /PROP/TYPE17 and /PCOMPP can be used with Madymo coupling.
  • Stacksize memory usage reduction in the Starter and Engine.
  • Parallel arithmetic to ensure the same numerical results whatever the number of processors is deactivated by default with the LS-DYNA input. The computation time will be reduced. (Parallel Arithmetic may be re-enabled via *CONTROL_PARALLEL card with flag CONST = 2).

Resolved Issues

LS-DYNA input format
  • *AIRBAG_SIMPLE_AIRBAG_MODEL: the set ID is not correctly updated in case the *SET ID is renumbered internally.
  • *BOUNDARY_PRESCRIBED_MOTION: reading correction in case the field VAD is empty.
  • *BOUNDARY_PRESCRIBED_MOTION_RIGID_ID: the orientation vector was not correctly read with DOF=4.
  • *CONTACT: correction of mapping for parameters SST and MST (optional contact thickness).
  • *CONTACT_AUTOMATIC_SINGLE_SURFACE: the contact with option TITLE was not correctly read.
  • *CONTROL_TIMESTEP: correction of maximum time step reading (LCTM).
  • *ELEMENT_BEAM_ORIENTATION: correction of orientation mapping to Radioss.
  • *ELEMENT_SEATBELT: the local coordinate system Skew_ID was not correctly read.
  • *ELEMENT_SEATBELT_SLIPRING: the parameter Ltime was not correctly read.
  • *LOAD_SEGMENT_SET: correction of the default value reading for scale factor Fscaley.
  • *MAT_032 (LAMINATED_GLASS): default number of integration points (F1 to F32 in the section shell) was not correctly considered.
  • *MAT_119 (GENERAL_NONLINEAR_6DOF_DISCRETE_BEAM): reading correction in case IUNLD=1 and unloading curve is not defined. Starter was printing an error.
  • *MAT_183 (SIMPLIFIED_RUBBER_WITH_DAMAGE): reading improvement in case Length, Wide and Thick are defined.
  • *SET_PART_LIST: this set was not converted correctly in case of truss components (standalone version only).
  • *SET_SEGMENT: segment from quadratic tetrahedron element was not correctly read.
Loadcases and contact interfaces
  • /CONVEC: wrong behavior for ordinate scale factor Fscale temperature in infinite room function fct_IDT.
  • /FRICTION and /INTER: the friction parameters C1 and Fric for Ifric=4 were reversed in the friction value computation.
  • /H3D/NODA/CSE_FRIC: results were missing.
  • /IMPDISP: correction of the printed information of the error message (ERROR ID: 120) in case function is missing for the imposed displacement.
  • /INIVEL: issue correction with initial velocity defined with Tstart or sensor and several Engine files.
  • /INTER/TYPE25: some contacts with quadratic tetrahedrons were not correctly detected on specific models.
  • /INTER/TYPE7, /INTER/TYPE19: correction of memory allocation issue for specific model.
  • /MASS/RESET: improvement of the mass reset feature for specific case.
  • /PRELOAD/AXIAL: correction of wrong behavior with /PROP/TYPE18 on a specific model.
  • /SET/GENERAL:
    • Issue to recover the edge in the contact interface /INTER/TYPE19 when the surfaces are defined by set (/SET).
    • Correction of the surface creation in case a coating shell of a solid part is removed from the set (using optional key suffix "D").
    • Reading correction where the key NODE_D is defined in the set. The nodes were not correctly removed.
    • Improvement of the edge defined with set, shell elements and PART_E.
    • The information about the node set defined with /SET was not correctly transferred to the Engine.
    • Correction of the option SET_D behavior. The entities were not correctly removed.
  • /STATE/BRICK: the flag Isolid=5 is now correctly written in /INIBRI cards of the .sta file.
  • /SUBDOMAIN: correction of contact interface /INTER/TYPE25 behavior in case the secondary node set is defined with a node group
Material and Failure models
  • /ALE: correction of instability issues when there are linear tetrahedron elements (/TETRA4) with Itetra4=3 and ALE solid elements in the same model.
  • /FAIL/FLD:
    • Radioss Engine was failing for specific models since version 2025.
    • Wrong initialization of strain type (Ismstr) in failure criteria reading.
  • /MAT/LAW4: improvement of thermal behavior for the elastic-plastic material laws.
  • /MAT/LAW21 (DPRAG): correction of the unloading behavior. There was a slope change when μ MathType@MTEF@5@5@+= feaahGart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeqiVd0gaaa@37AD@ < 0 along the unloading path.
  • /MAT/LAW81: update and correction of the user variable USRi.
  • /MAT/LAW108 (SPR_GENE), /MAT/LAW113 (SPR_BEAM): wrong computation in the rotational degree of freedom during the unloading phase for unloading behavior defined by curve.
  • /MAT/LAW119 (SH_SEATBELT):
    • Improvement of the spring creation for specific modeling.
    • Correction of the Starter ERROR message #1716 title.
    • There is no longer an error in the case a seatbelt with spring element (/MAT/LAW114) is connected to a shell seatbelt (/MAT/LAW119).
  • /MAT/LAW126 (JOHNSON_HOLMQUIST_CONCRETE): improvement of the material law in case of cyclic pressure load.
  • /MAT/USERij (USER):
    • Plastic strain output was reset to 0 for some integration points.
    • It was no longer possible to use Ismstr=10 with shell element and user material law.
Element and properties
  • The membrane damping default value for QEPH shell element (Ishell=24) was set to dm=0.0 instead of dm=0.015 for the material laws /MAT/LAW1, /MAT/LAW2 and /MAT/LAW22. Results from previous versions may change, element stability is improved.
  • /PROP/SH_ORTH: the local coordinate system Skew_ID was not correctly read.
  • /PROP/SPR_PRE: Correction of the Starter output in case only the time function is defined.
  • /PROP/TYPE14 (SOLID): Correction of automatic Ismstr (Ismstr = -1) assignment for specific model with solid element and failure model (/FAIL).
  • /RETRACTOR/SPRING: Behavior improvement to get more physical results.
  • /SLIPRING/SHELL: The elements in the slipring are no longer removed from the contact interface defined with Idel > 0.
  • /SLIPRING/SPRING: Correction of slipring behavior with nonlinear elastic material and for locking behavior.
Animations and time history output
  • Tensors for integration points 2 to 4 output are missing in the animation files for quadratic tetrahedron elements:
  • Improvement of the internal energy output in animation file (/ANIM/BEAM/ENER, /H3D/BEAM/ENER) of the beam element (/PROP/TYPE3).
  • Correction of the element type in native .h3d output file to be more compatible with the input deck (_0000.rad) file for 4-node shell elements.
  • Detonation time output (/H3D/ELEM/TDET) was not output with 3-node 2D solid elements (/TRIA).
  • Maximum stress values /H3D/NODA/GPS/TMAX could decrease during the simulation for specific models.
  • Only the first integration point was output for the tensor (/ANIM/BRICK/TENS/*/ALL) of the quadratic tetrahedron element (/TETRA10).
Starter and Engine
  • /MADYMO: Madymo coupling was non-functional since version 2024 because of compilation process change.
  • Correction of model decomposition for specific model, with small rigid bodies (/RBODY) linked to the middle node of quadratic tetrahedron element (/TETRA10).