# Altair Radioss 2022 Release Notes

## Highlights

• 139 LS-DYNA input keywords can now be read in Radioss with many enhancements for the already supported keywords.
• New 1D seatbelt, slipring and retractor models to enhance Radioss capabilities for automotive passive safety.
• New input for the Multiscale Designer material law with specific output in the .h3d files.
• Many enhancements and corrections for material laws and other features.
• MPI versions updated to Intel MPI 2021.2 (win64 and linux64) and OpenMPI 4.1.12 + UCX 1.12.0 (linux64 only).

## New Features

Failure model /FAIL/ORTHBIQUAD
• New failure model based on /FAIL/BIQUAD formulation with orthotropic behavior
Cohesive material /MAT/LAW117
• New connection material law with failure criteria
Multiscale Designer material /MAT/LAW200 (MDS)
• New user material interface with Multiscale Designer solver
• /H3D/MDS/…: New specific outputs in the .h3d files have also been added
• New Starter and command argument to define the location of the MDS library. By default, the environment variable defined by the HWSolvers installer are used.
Spring for railway coach bumper
• /PROP/SPR_BDAMP: New spring property with bounded damper effect dedicated for railway coach bumpers
Seatbelt for 1D elements
• /MAT/LAW114: New seatbelt material law for spring elements (/PROP/TYPE23)
• /RETRACTOR/SPRING: New entity to model seatbelt spooling force pull-in, active pretensioner and load limiter, for spring elements defined with material /MAT/LAW114. The force, slip, and status can be output in time history file (/TH/RETRACTOR).
• /SLIPRING/SPRING: New entity to model seatbelt sliprings for spring elements defined with material /MAT/LAW114. The force and slip can be output in time history file (/TH/SLIPRING).
Equations of State (EOS) and ALE features
• /EOS/IDEAL-GAS-VT: New EOS based on the ideal gas formulation taking into account heat capacity and temperature
• /EBCS/NRF: New boundary condition option to model Non-Reflecting Frontier which can be used with all ALE material laws
LS-DYNA keyword reading
The following additional keywords are implemented or supported in Radioss:
• *CONTACT_NODES_TO_SURFACE
• *DEFINE_TRANSFORMATION
• *INTEGRATION_SHELL
• *LOAD_GRAVITY_PART
• *LOAD_SHELL
• *PERTURBATION_NODE
• *SET_SEGMENT_GENERAL
• *CONTROL_MPP_<parameters>[1]
• *DATABASE_BINARY_XTFILE[1]
• *DATABASE_EXTENT_AVS[1]
• *DATABASE_EXTENT_MOVIE[1]
• *DATABASE_FORMAT[1]
[1]Card is read but ignored for Radioss Computation.

## Enhancements

Contact interfaces
• /INTER/TYPE18: The values used to compute automatic stiffness of the FSI contact interface are now printed in the Starter output file
Materials and failure models
• /MAT/LAW0 (VOID): Void material is now compatible with spring /PROP/TYPE23
• /MAT/LAW35 (FOAM_VISC): New strain rate filtering parameters
• /MAT/LAW36 (PLAS_TAB):
• Elements (solid, shell, beam) are automatically deleted when the yield stress is null. This feature enhances model robustness
• Reduction of the computation time for this tabulated elasto-plastic material applied to solid elements
• /MAT/LAW41 (LEE_TARVER): Unit system can be defined for this material law
• /MAT/LAW43 (HILL_TAB): Strain rate filtering is added in the material law. Equivalent strain rate is available in the animation files (A-files and .h3d file).
• /MAT/LAW51 (MULTIMAT): The recommended formulation /UPWM/SUPG is activated by default for 2D axisymmetric analysis
• /MAT/LAW57 (BARLAT3): Strain rate filtering is added in the material law. The filtered strain rate can be seen in the animation files
• /MAT/LAW71: Material model stability improvement for some specific loading and phase changes
• /MAT/LAW76 (SAMP): Improvement of the material behavior with additional check for the input
• /MAT/LAW78: Enhanced to support additional options during unloading
• /MAT/LAW80: Enhanced material law with new developments in hot stamping and press hardening to better predict the martensite volume fraction
• /MAT/LAW83: New elastic modulus for compression Ecomp and new option Icomp = 1 to have a linear elastic behavior in compression and elastic-plastic behavior in tensile
• /MAT/LAW87 (BARLAT2000):
• New default values of the strain rate filtering
• New hardening formulation based on Chaboche & Rousselier formulation and Hansel formulation
• /MAT/LAW92: Default value for D is now recomputed from the input value and NU = 0.495
• /ALE/MAT, /EULER/MAT:
• The flag Flrd is removed from the ALE and EULER material definition because the method used is obsolete and may lead to numerical issues
• The external boundary of the domain is closed by default
• Material transfer through the boundary can be done using material /MAT/LAW11 or /MAT/LAW51 or specific boundary /EBCS
• /FAIL/ALTER: New parameter from the PhD Thesis of Christopher Brokmann to improve the failure behavior for the windshield. Several improvements in the algorithms have been implemented during this development
• /VISC/PRONY: New viscous model defined by time relaxation curve or Dynamic Mechanical Analysis (DMA). Radioss automatically fits the Prony series values
Load Cases
• /PLOAD: New option Idel = 1 to stop load application when element is deleted
• /LOAD/PBLAST: New feature to correlate positive impulse in addition to positive peak pressure
Elements and properties
• /PROP/TYPE17: New parameter to define viscosity for the inter-ply material (Vinterply). It is also possible to add a material between sub-plies (INT).
• New error message in case the material law /MAT/LAW88, /MAT/LAW92 or /MAT/LAW94 is used with non-compatible elements
• New option Ip to define the reference material direction with some new capabilities for the orthotropic shell properties /PROP/TYPE9, /PROP/TYPE10, /PROP/TYPE11, /PROP/TYPE16, /PROP/TYPE17, /PROP/TYPE51 and /STACK
• New option Ip to define the composite material orientation in the orthotropic solid element /PROP/TYPE6
Tools
• /SENSOR/ENERGY:
• New feature to activate the sensor when the internal or kinetic energy is constant during a defined time value
• New feature to activate the sensor with total energy
LS-DYNA keyword reader
• *CONTACT_AUTOMATIC…, *CONTACT_ERODING_SINGLE_SURFACE...: The parameter SOFT of the additional Optional Card A is read and mapped into Istf in the corresponding contact interface /INTER/TYPE25
• *DATABASE_BINARY_INTFOR: Option FILE is now handled. Contact pressure (/ANIM/VECT/PCONT) is added in the animation files.
• *INITIAL_VELOCITY: Initial velocity applied on a rigid material or rigid body is now automatically applied on the rigid body main node. The exempted node set is ignored for the primary velocities (secondary velocities not yet implemented).
• *MAT_024 (PIECEWISE_LINEAR_PLASTICITY): Improvement of the failure parameter setting in Radioss with FAIL > 0. The material was failing when 1 integration point through the shell thickness reached the limit instead of all of them.
• *MAT_034 (FABRIC): Improvement of the reading in case E2 = 0. It is now understood as E2 = E1.
• *SET_..._COLLECT: The option COLLECT is handled for all sets
• *SET_..._INTERSECT: The option INTERSECT is handled for sets of type BEAM, DISCRETE, NODE, SEGMENT, SHELL and SOLID
Initial state and conditions
• *ELEMENT_SHELL_THICKNESS_BETA: This option is now written in the .dynain file (/DYNAIN)
• /INIBRI/EREF: New option to initialize solid element with total strain or small strain formulations. The option /STATE/BRICK/EREF is used to write the data in the .sta file.
• /STATE/NO_DEL: The non-active elements (non-active, defined in rigid bodies) are now kept in the .sta file with the keyword
• /STOP/LSENSOR: New flag to output state file with LS-DYNA format ( .dynain)
• /INIVOL: Volume fraction initialization can be done with a hyper-ellipsoid surface /SURF/ELLIPS
Animation and time history outputs
• The display of the global coordinate system is removed in the native .h3d file (H3D)
• Information about the units is written in the header of the .h3d file
• /ANIM/VECT/PCONT2, /H3D/NODA/PCONT2: New output options to display the contact pressure from tied interface (/INTER/TYPE2)
• /H3D/SHELL/PEXT, /H3D/SOLID/PEXT: New output to display the pressure imposed by the options /PLOAD, /LOAD/PFLUID, /LOAD/PBLAST or /BEM/DAA
• /H3D/RBODY/SINGLE_PART: New option to display only 1 component for all RBODY. By default, there is 1 component per rigid entity with its own name.
• /H3D/RBE2/SINGLE_PART: New option to display only 1 component for all RBE2. By default, there is 1 component per RBE2 with its own name.
• /H3D/RBE3/SINGLE_PART: New option to display only 1 component for all RBE3. By default, there is 1 component per RBE3 with its own name.
• /H3D/TRUSS/TENS/STRAIN, /H3D/TRUSS/TENS/STRESS, /ANIM/TRUSS/EPSX: New options to display the stress and strain tensor of the truss elements
• /TH/TRIA: New time history output for 2D solid elements
• /TH/BRIC, /TH/QUAD, /TH/TRIA: New outputs for 2D and 3D solid elements to display material velocity, speed of sound & Mach number in the time history file
Other Starter keywords and messages
• ALE, Euler and /DFS options can now be used inside a submodel (//SUBMODEL)
• The 2D solid element /TRIA is now compatible with submodel (//SUBMODEL)
• The message #666 for the solid element connectivity is no longer relevant and has been removed from the Starter output file
• Reduction of the computation cost for the option /CYL_JOINT with SPMD/HMPP version.
• The recommended formulation /ALE/MUSCL is now activated by default. This behavior can be reset with the keyword /ALE/MUSCL/OFF in the Engine file.
• New error message in case option Itetra10 = 2 in the solid property and Advanced Mass Scaling (/AMS) are defined together in the model. These options are not compatible with each other.
• New warning message in the Starter output file in case Batoz shell element (Ishell = 12) is used with XFEM failure model (not compatible). The XFEM flag is automatically switched off for the failure model.
• /MONVOL/FVMBAG1, /MONVOL/FVMBAG2: New option Iswitch = 2 to reduce the airbag to a single finite volume in order to save CPU time and keep exactly the same gas properties
• New error message in case the number of Prony coefficients M is null in the card /VISC/PRONY
Engine keywords
• /IMPL/QSTAT/MRIGM: New option to input 3 reference nodes for the rigid body mode computation
• /INIV/AXIS/Keyword3/2: New option to define initial velocity on a node set of the model
• /INIV/ROT/Keyword3/2: New option to define rotational initial velocity on a node set of the model
• /INIV/TRA/Keyword3/2: New option to define translational initial velocity on a node set of the model
• The Label field is now the same as parameter name (/PARAMETER) in the specific file for the HyperStudy interface (generated by command line -HSTP_WRITE)

## Resolved Issues

LS-DYNA keyword reader
• *BOUNDARY_PRESCRIBED_MOTION_RIGID: The rigid body main node was added several times in /TH/NODE and Radioss Starter printed an error message
• *CONSTRAINED_EXTRA_NODE_SET: Set of parts was used instead of set of nodes in cases where both sets had the same ID.
• *CONSTRAINED_NODAL_RIGID_BODY: The case where NSID = 0 is now taken into account (NSID = rbody_ID).
• *MAT_ARUP_ADHESIVE: The failure model created during the mapping was not referring to the right material ID in case there were several *MAT_ARUP_ADHESIVE cards in the model or the material was used in several parts
• *MAT_SIMPLIFIED_RUBBER: Correction of the material reading in case there is only a single stress/strain curve instead of a table. Radioss Starter was failing without error message.
• *MAT_SPOTWELD: Correction of the spot weld material reading with specific model. The created functions were not correctly referred to, and failure models were created even if not necessary.
• *SECTION_BEAM: Setting improvement for reading the beam element *SECTION_BEAM with ELFORM = 1, 4. The parameter df in the integrated beam (/PROP/TYPE18) is reset to 0 in order to avoid large mass increase.
• *SET: Set of elements was not defined in several options in case the set ID was the same as the set of nodes
Materials and failure models
• /MAT/LAW6: Correction of the information printed in Starter output file (_0000.out) file
• /MAT/LAW/25:
• All elements were deleted from time 0 when the flag Ioff = 1 was set for specific model
• Correction of variable initialization for QEPH shell element. Computation was failing with segmentation fault with specific models.
• /MAT/LAW28, /MAT/LAW50, /MAT/LAW68: The input maximum value for shear strain was compared to the gamma component, and not the shear strain (gamma = 2 * shear strain). The failure occurred sooner than expected.
• /MAT/LAW43: Correction for the strain rate output
• /MAT/LAW44: Numerical stability improvement of the failure model (/FAIL) with single precision version. Radioss Engine was failing with specific model and configuration.
• /MAT/LAW51: Improvement of the material stability for some specific meshes. Computation was failing with negative density.
• /MAT/LAW70:
• Improvement of the foam behavior with Ismstr = 11. The results were not identical to Ismstr = 1 for specific model under simple loading.
• Improvement of the foam material stiffness computation with HEPH solid formulation (Isolid = 24). The material was too stiff compared to other solid formulations or other element types.
• /MAT/LAW71:
• Correction of the equivalent stress for beam elements (/PROP/TYPE18). Differences were observed in equivalent stress (2/3 factor).
• Correction of shell behavior which was giving non expected behavior
• Material model stability improvement for some specific loading and phase change conditions
• /MAT/LAW80: Correction of numerical instability for specific hot forming application
• /MAT/LAW87: Correction of potential numerical issue (NaN) with Single Precision version
• /MAT/LAW90:
• Improvement of the foam material with HEPH solid formulation (Isolid = 24). The element was too stiff compared to the other solid formulations.
• The first reference strain rate is reset to 0 to avoid incorrect extrapolation. Warning message is printed in the Starter output file.
• Improvement of the stress initialization when reference geometry is defined on the part (/XREF)
• /MAT/LAW93: Correction for /PARITH/ON issue when using tabulated yield stress with strain-rate effect
• /MAT/LAW104: Correction for the strain rate output
• /MAT/LAW111: Compression behavior improvement in case the input curve is defined for tensile direction only
• /MAT/LAW112: Improvement of the output of plane stiffness computation (direction Z)
• /MAT/LAW113: Correction of elementary time step when Ileng = 1
• /MAT/LAW115: Correction of algorithm check issue Istat = 1. Starter was printing an incorrect error message.
• /MAT/LAW116: Improvement of the cohesive material /MAT/LAW116 behavior for the mixed mode condition. The failure behavior was not happening at the correct displacement/absorbed energy.
• /MAT/USERij: User materials were not getting the correct strain values for specific cases
• /FAIL/BIQUAD: Correction of the regulation behavior for solid elements in the failure model /FAIL/BIQUAD
• /FAIL/HASHIN: Improvement for the Hashin failure model (/FAIL/HASHIN) for the computation of the criteria F2 for the lamina formulation. Non-expected failure was occurring for specific model.
• /FAIL/TAB1: The scale factor Xscale1 and Xscale3 was transformed to 1/Xscale1 and 1/Xscale3. The failure model /FAIL/TAB1 was giving different results since version 2021.
• /FAIL/TENSSTRAIN: Correction of the computation of the principal strain for Iflag = 3 in the failure model /FAIL/TENSSTRAIN
• /FAIL/VISUAL: Correction of the animation file output for the damage value on quadratic tetrahedron elements
Elements and properties
• /PROP/SHELL: Reporting correction of the flag Idril value in Starter listing file. Value was reported as 0 instead of 2.
• /PROP/TRUSS: Gapini > 0 has a wrong behavior and initial truss length was not correctly output in the time history file.
• /PROP/SOLID: Strain formulation Ismstr = 12 has been improved to remove potential numerical stability issues for elastic material (/MAT/LAW1). This flag is now set as recommended value (activated with Ismstr = -1 in the solid property or Ismstr = -1,-2 in the default solid card).
• /PROP/SPRING: Correction for the unit translation of the spring stiffness
• /PROP/TYPE26: Improvement of the stability issue during compression unloading. Unexpected tensile force could be seen in specific model.
• /PROP/TYPE14: Correction of numerical stability issue with Itetra10 = 2 and /ADYREL under specific loading conditions
• /PROP/TYPE17: Correction of variable initialization for the composite property /PROP/TYPE17. The behavior was not correct with Ipos > 0 and Iskew > 0.
• /PROP/PCOMPP: Correction of the information stored in the restart files. The second Engine was failing during the restart file reading.
• /PROP/PCOMPP: Correction of ID offset for submodel (//SUBMODEL)
• /PROP/PLY, /PLY: Correction for the element orthotropic direction when the angle is defined in the shell element (/SHELL) and the flag def_orth = 1 is set in the /PLY card. The angle defined in the shell was not read as degrees.
• /PROP/TYPE43 (CONNECT): Initial state (/INIBRI) import correction for the connection solid element (/PROP/CONNECT). Incorrect error message was displayed.
• /PROP/TYPE45 (KJOINT2): Default values for parameters Kti and Cti were not correct.
Contact interfaces
• /INTER/TYPE18: Behavior improvement with the multi-fluid material /MAT/LAW151. Computation was failing for specific models.
• /INTER/TYPE21: Correction of numerical issue for forming contact /INTER/TYPE21 with initial penetration and the output file option Ipri = 5 (/IOFLAG). Radioss Starter was failing.
• /INTER/TYPE25:
• Improvement of MPI communication
• Correction of error message calling. Radioss Starter was calling a non-existent error message.
• Correction for the sorting of the edge to edge contact with initial penetrations. The computation may fail with segmentation fault for specific cases.
• Correction of compiling issue for the contact interface /INTER/TYPE25 with recent Xeon CPU (AVX512 capable). Radioss Engine may fail for specific models. o Correction of friction value initialization to avoid memory issue.
• Reduction of the CPU time used for the non-active interface (before Tstart or after Tstop)
• /INTER/TYPE7: Correction of incorrect thermal behavior in contact interface with SPMD/HMPP version
• /SURF/SURF: Correction of the segment orientation for 2D analysis for the contact surface defined with /SURF/SURF and negative ID
• /SURF/DSURF: Improvement of the surface deletion for some specific cases when segment was removed from solid part. Some segments were not correctly removed.
Initial state and conditions
• /INIBRI/STRA_F: Correction of the data reading for the initial strain. Radioss Starter was failing for specific model.
• The solid formation reported in the cards /INIBRI/STRA_F, /INIBRI/AUX for quadratic tetrahedron element (/TETRA10) was Isolid value instead of 1, the only formulation available for quadratic tetrahedron elements
• /INIBRI/STRESS/*: Correction of the stress initialization and output for material laws for orthotropic solid property (/PROP/TYPE6)
• /INIMAP: Correction of possible wave reflection on Non-Reflecting Frontier (NRF) modeled with /MAT/LAW51
• /INISH3/FAIL: This keyword is not correct when data is written in .str file (/STATE/STR_FILE) and triangle element has the same ID as shell element
• /INISHE, /INISH3: Following the removal of the global integration model (N = 0) for the elastic-plastic material law, an error message is printed in case the initial state for shell element is defined with global integration model
• /INIVEL/AXIS: Correction of the rigid body main node velocity. The velocity was defined before the main node had been moved to its initial position.
• /INIVOL: Correction of the initial volume initialization for parts which are not defined in the /INIVOL cards
Other Starter keywords and messages
• //SUBMODEL: Radioss Starter was failing when different values were set in the offset fields of the submodel card
• /ACTIV: The time step could drop on some specific models with element de-activation and rigid body
• /CNODE: The unit system is not correctly handled for the search merging distance.
• /EBCS/GRADP0: Correction of the boundary formulation. The adjacent pressure was not correctly transferred.
• /MONVOL/FVMBAG1, /MONVOL/FVMBAG2:
• Correction of memory allocation issue. Engine could fail for specific case
• Time step and merge parameters defined in the card /MONVOL/FVMBAG* were not correctly printed in Engine for SPMD and HMPP computations
• Improvement of the finite volume meshing method with kmesh = 12,14. The initial number of finite volumes was different for each run.
• /MONVOL/GAS: Improvement of the compatibility between Trelax and the venting options with Ideleted = 1
• /PLOAD: The 3rd node of the 3 node segment linked to TETRA4 element was receiving 2 times the force generated by the pressure
• /RBE3:
• Memory allocation correction for the RBE3 with specific model
• The Engine was failing with segmentation fault since version 2021
• Corrections of the IDs of the message #805,1036,806,807,810 printed in the Starter output file (_0000.out)
• /SET:
• Correction of memory initialization issue for the created lines and surfaces
• Robustness improvement in case an element defined in a /SET is not existing in the model
• /TABLE: Correction of numerical issue in the table interpolation for specific model
• Correction of memory allocation issue when using rotational initial velocity in a model which is containing only solid elements. Radioss Starter was failing.
Engine keywords
• /ABF: Numerical issue correction in case /ABF is set in the Engine for specific model. The total energies output was corrupted.
• /ANIM: Incorrect error message was displayed for the non-existing option /ANIM/ELEM/MASS (this option exists only with native H3D format).
• /ANIM/BRICK/TENS/STRESS: Output issue correction for the composite thick-shell (/PROP/TYPE22) stress output for the different integration points through the thickness.
• /DYNAIN: The first character of some comment lines was #" instead of "\$" in the written .dynain file.
• /H3D: With solid splitting to SPH (Sol2Sph), the "non active" SPH particles were displayed from initial time instead of being displayed when they became active
• /H3D/ELEM/VECT/VEL: Correction of visualization issue of elemental velocity vector in 2D analysis with /MAT/LAW151
• /H3D/ELEM/VOLU: Improvement of the evaluation of volume of the 3D solid element with ALE formulation
• /H3D/SHELL/TENS/…: Tensors for shell elements were not correctly output in native .h3d output file in case there were only 3 node shell elements (/SH3N) in the model
• /H3D/SOLID/DAMA: Damage output for all solid integration points (/H3D/SOLID/DAMA/IR=ALL/IS=ALL/IT=ALL) was incorrect
• /H3D/SOLID/DAMG: Correction of the output /H3D/SOLID/DAMG initialization. Wrong value was displayed on the non-active elements.
• Stress (/H3D/SOLID/TENS/STRESS) and strain (/H3D/SOLID/TENS/STRAIN) tensors was no longer output in the native .h3d file for thick-shell element /PROP/TYPE20 (TSHELL), /PROP/TYPE21 (TSH_ORTH), /PROP/TYPE22 (TSH_COMP) since version 2021
• /STATE/DT: The card /BEGIN with units was not written in the .sta file when .str file was requested (/STATE/STR_FILE)
• /STATE/SHELL/*: The card /INISH3/STRA_F/GLOB was not correctly written for 3 node shell elements (/SH3N) for composite properties /PROP/TYPE9, /PROP/TYPE17 and /PROP/TYPE51
• /STATE/STR_FILE: The initial state data /STATE/BRICK/ORTHO was missing in the .str file.
• /STATE/SHELL/STRAIN/GLOBFUL: Improvement of the option in case the output is requested for a lot of parts. The created .sta file was corrupted.
• /H3D/SPRING/FORC, /H3D/BEAM/FORC, /H3D/TRUSS/FORC: Correction of the 1D element force and moment writing in the .h3d file which was not readable
• /TH/BRICK: Correction of the output for the stress tensor of the composite thick-shell elements. The tensor component name was not corresponding to the expected one.