Altair Radioss 2023.1 Release Notes

Highlights

  • Enhancement of the Radioss reader with LS-DYNA format input.
  • Continuous improvement of the Radioss features and capabilities for materials and elements.
  • New simplified rules for the treatment of the P_thickfail flag in shell properties and failure models. Some changes in results are expected for specific cases.

New Features

LS-DYNA format cards now supported in Radioss reader
  • *CONTROL_HOURGLASS
  • *DATABASE_HISTORY_SEATBELT
  • *DEFINE_TABLE_3D
  • *ELEMENT_SEATBELT
  • *ELEMENT_SEATBELT_SLIPRING (for 1D only)
  • *HOURGLASS
  • *LOAD_BODY_PARTS
  • *LOAD_SEGMENT
  • *LOAD_SEGMENT_SET
  • *MAT_012 (ISOTROPIC_ELASTIC_PLASTIC)
  • *MAT_019 (STRAIN_RATE_DEPENDENT_PLASTICITY)
  • *MAT_054 (ENHANCED_COMPOSITE_DAMAGE)
  • *MAT_058 (LAMINATED_COMPOSITE_FABRIC)
  • *MAT_076 (GENERAL_VISCOELASTIC)
  • *MAT_120 (GURSON)
  • *MAT_224 (TABULATED_JOHNSON_COOK)
  • *MAT_B01 (SEATBELT)
  • *MAT_S15 (MAT_SPRING_MUSCLE)
All supported parameters are described in the Reference Guide.
Materials and Failure models
  • /MAT/LAW122 (MODIFIED_LADEVEZE): new material law for shell and solid elements to model unidirectional continuous fiber reinforced composite.
  • /MAT/LAW124 (CONC): new concrete material law based on CDPM2 formulation.
  • /VISC/LPRONY: new option to use total strain formulation in the Prony series. This new option is recommended for materials using total strain formulation, such as rubber material, or when there is very high viscous stiffness.
Loading and Boundary Conditions
  • /LOAD/PCYL: new load pressure with cylindrical shape projected on a surface and tabulated pressure according to cylinder radius and time. The applied pressure can be seen with the output /H3D/ELEM/PEXT.
Animation and Time History files
  • /H3D/ELEM/DIV(U): new volumetric dilatation rate output (DIV_U) to measure the divergence of velocity versus the incompressible flow hypothesis.
  • /H3D/NODA/VEL/GRID: new H3D output for ALE grid velocity.

Enhancements

LS-DYNA reader
  • The boundary *BOUNDARY_SPC_SET option is ignored in cases where the node set is not defined. A warning message is printing in the Starter output file.
  • Reading improvement in case *BOUNDARY_PRESCRIBED_MOTION is applied on the secondary node of a rigid body built from a node set.
  • Option LOG_INTERPOLATION is now read in material *MAT_024 (MAT_PIECEWISE_LINEAR_PLASTICITY).
  • Damping parameter Mu is now read in materials *MAT_057 (LOW_DENSITY_FOAM) and *MAT_083 (FU_CHANG_FOAM).
  • The material *MAT_074 (ELASTIC_SPRING_DISCRETE_BEAM) is now mapped to /MAT/LAW113 for more accurate results.
  • The parameters EXPON, FAIL, TFLAG and stress cut in tension TC are now read in the material *MAT_083 (FU_CHANG_FOAM).
  • The parameter Mu is added in the reader for the material *MAT_181 (SIMPLIFIED_RUBBER/FOAM).
  • This material *MAT_009 (NULL) can be used for beam and truss elements.
  • The optional node_ID defined in *PART_INERTIA is now removed from the secondary node set of the rigid body.
  • New capability to read the number of integration points in the integrated beam property *SECTION_BEAM.
Element and Properties
  • /PROP/TYPE14 (SOLID): new hourglass formulation for solid element Isolid=5 for better element stability for soft materials. The hourglass energy is higher.
  • /PROP/TYPE17 (STACK): improvement of Starter error message #373.
  • /PROP/TYPE1 (SHELL): new warning message in case Ismstr=10 is defined with /MAT/LAW1 (ELAST) and the formulation is automatically reset to default value.
  • The PLY ID in now printed in the Engine output file for ply based composite shell elements (/PROP/TYPE17, /PROP/TYPE51, /STACK) which reach failure and damage criteria.
  • New simplified rules for the treatment of the P_thickfail in the shell properties. Some changes in the results are expected for specific cases.
  • The option P_thickfail is not available in the stack properties /PROP/TYPE17 and /STACK.
Materials and Failure models
  • The composite Chang-Chang failure model (/FAIL/CHANG) is now compatible with solid and thickshell elements.
  • The following failure models can be used for beam elements (/PROP/TYPE3 and /PROP/TYPE18).
    • /FAIL/COCKCROFT (only for /PROP/TYPE18)
    • /FAIL/ENERGY
    • /FAIL/JOHNSON
    • /FAIL/TENSSTRAIN
  • /FAIL/FABRIC: new flag NDIR to select whether the element deletion appears when single or both directions reach the maximum damage (D=1).
  • /FAIL/ORTHSTRAIN:
    • Default values for failure strain values are now 1E+20 and maximum strain values are 1.2E+20 for all directions.
    • Improvement of the failure message in the Engine file. The different failure modes are now written instead of mode # number.
  • /FAIL/SYAZWAN: now available for solid elements.
  • /MAT/LAW2 (PLAS_JOHNS): new option VP for different rate effect formulations (total, plastic deviatoric).
  • /MAT/LAW11 (BOUND): new check in the density function to avoid incorrect material behavior.
  • /MAT/LAW41 (LEE_TARVER): variable names updated to be closer to the references and publications.
  • /MAT/LAW42 (OGDEN): new strain energy formulation to better model incompressibility.
  • /MAT/LAW69: new flag law_ID=-1 to enable automatic fitting. Radioss Starter selects the best material law and parameters to better fit the input curve.
  • /MAT/LAW71: shape memory alloy material is now compatible with integrated beam elements (/PROP/TYPE18).
  • /MAT/LAW79 (JOHN_HOLM):
    • With D1=D2=0, the behavior is now perfectly plastic.
    • New simple failure models in the material law.
  • /MAT/LAW104 (JOHNS_VOCE_DRUCKER): new option to set the strain rate filtering frequency.
  • /MAT/LAW117: new check and warning in Radioss Starter for the consistency for energy release to avoid too brittle failure.
  • /NONLOCAL/MAT:
    • Non-local approach is now fully-compatible with RAD2RAD method
    • Non-local approach compatible with thick-shell /PROP/TYPE20, /PROP/TYPE21
    • Improvement of the erosion treatment for solid elements
  • /PERTURB/FAIL/BIQUAD: perturbation method is available for solid elements.
  • /VISC: viscosity models can now be used for any material law compatible with solid elements.
Loading and Boundary Conditions
  • /FXBODY: improvement of the reading and initialization for flexible body defined with KAAX, MAAX definition.
  • /RLINK: new error message in case a rigid link is defined on the middle node of the quadratic tetrahedron element (/TETRA10) with dynamic condensation (Itetra10=2).
  • /SENSOR/ENERGY: improvement of the sensor behavior to detect constant internal or kinetic energy which are almost null.
Contact interfaces
  • /INTER/TYPE24: improvement of the contact stiffness definition for the pressfit (Inacti=-1) option to better solve the initial penetration.
  • /PART: the option to define contact gap "thick" is now available for spring, beam and truss elements.
Animation and Time History files
  • Pressure, fluid velocity, speed of sound, temperature, volume and gas density of the finite volume centroid is now displayed in the native H3D output file (.h3d) for the airbags /MONVOL/FVMBAG1 and /MONVOL/FVMBAG2.
  • /H3D/ELEM/FAILURE:
    • The option ID=ALL is now available
    • This output is now available for SPH elements.
  • /TH/BRIC: the outputs BFRAC, SSP, MACH, VX, VY and VZ are now exported for all relevant material (laws 5, 41, 51, 97, 151).
  • /TH/PART: new output for the average velocity VX, VY, VZ of the part.
  • New output to display the number of deleted elements during the computation as global output, for each part (/TH/PART) or subset (/TH/SUBS) selected in the time history.
Radioss Starter output file
  • /IOFLAG: the element groups from domain decomposition are now printed in the Starter output file only if Ipri > 6 in the card /IOFLAG.
  • Improved writing of part mass and inertia summary to Starter output file for better readability.
  • //SUBMODEL: new error message in case entities not compatible with submodel are defined inside a submodel.

Resolved Issues

LS-DYNA reader
  • /INCLUDE_LS-DYNA: correction of the set/group numbering where /INCLUDE_LS-DYNA is used in input deck.
  • *ELEMENT_SHELL_THICKNESS: thickness is taken into account for non-zero or defined thickness values only.
  • *MAT_002 (ORTHOTROPIC_ELASTIC): improvement of the material reading according to the new capabilities in Radioss to define the orthotropic directions (Flag IP in the shell and solid properties).
  • *MAT_034 (FABRIC): improvement of the mapping for FORM=+/-14 in the property card.
  • *MAT_077_O (OGDEN_RUBBER): reader correction if the parameter N is not defined (blank). Radioss Starter was printing an incorrect error message.
  • *MAT_123 (MODIFIED_PIECEWISE_LINEAR_PLASTICITY): improvement of the material reading and mapping for maximum plastic strain EPS_MAX.
  • *MAT_S04 (SPRING_NONLINEAR_ELASTIC): improvement of the material reading. Stiffness scale factor was not correctly defined.
  • *SET_PART_ADD: improvement of the part set reading. Contact surface was not correctly generated for some specific models.
Element and Properties
  • /PROP/TYPE51: output per ply (stress, strain, damage, ...) for composite with /MAT/LAW01, /MAT/LAW02, /MAT/LAW22 and /MAT/LAW32 were missing.
  • Improvement of the Starter error message in case /PROP/TYPE19 (PLY) is defined in a /PROP/PCOMPP.
  • /PROP/TYPE11 (SH_SANDW): the tensor was not output when all layer and integration points were requested (/H3D/SHELL/TENS/.../LAYER=ALL/NPT=ALL)
  • /PROP/TYPE13 (SPR_BEAM): Starter output correction for zero length spring element identifier which was not the correct one for specific model.
  • /PROP/TYPE14 (SOLID) and /PROP/TYPE6 (SOL_ORTH)
    • Result was different between Isolid=18 and Isolid=24 when Navier-Stockes parameters were applied in the solid property.
    • Improvement of the quadratic tetrahedron element (/TETRA10) + elasto-plastic material laws
    • Element quality criteria are now working well for /TETRA10 elements (Itetra10=2,3)
    • Improvement of the QEPH formulation with recommended parameters (Ismstr=Icpre=Iframe=-1) for hyperelastic material /MAT/LAW92.
  • /PROP/TYPE18 (INT_BEAM):
    • Improve the integrated beam element stability for specific load-case.
    • Improvement of the strain formulation for integrated beam elements.
  • /PROP/TYPE20 (TSHELL), /PROP/TYPE21 (TSH_ORTH) and /PROP/TYPE22 (TSH_COMP):
    • Correction of the animation output (/ANIM and /H3D) for each integration point for the different configuration defined with flag Icstr.
    • New warning message in case a non existing Ismstr flag is used in the thickshell property. It is automatically reset to the recommended value (Ismstr=-1).
    • Improvement of the check for the compatibility between thickshell and material law.
    • Improvement of the under-integrated thickshell element (Isolid=15) stability.
  • /QUAD: hourglass energy is no longer accumulated for 2D solid elements with EULER or ALE framework. It was already the case with 3D analysis.
Materials and Failure models
  • /FAIL/BIQUAD: issue in case there are several failure models with and without mesh size regularization in the same model. The results were wrong for the failure model without mesh size regularization and for specific models.
  • /FAIL/ENERGY: improvement of the stress softening for solid, shell and beam elements.
  • /FAIL/GENE1:
    • Correction of the failure model behavior for 3 noded shell elements (/SH3N) and constant nodal time step (/DT/NODA/CST). Elements were deleted because of incorrect time step setting.
    • P_thickfail defined in the failure model /FAIL/GENE1 have priority over the same parameters in shell property (/PROP/SHELL).
  • /FAIL/TAB1: Improvement of the mesh size regularization feature for specific model.
  • /MAT/LAW121 (PLAS_RATE): correction of the Radioss Starter reader.
  • /MAT/LAW151 (MULTIFLUID): improvement of the material stability under specific loadcase.
Loading and Boundary Conditions
  • /CLOAD:
    • New error message if the node group is missing in the concentrated load.
    • Improvement of error message #54: the card with the error was not correctly printed.
  • /EBCS/NRF: correction of potential SPMD memory corruption issue for specific model.
  • /GAUGE: new error message if the referenced node or element does not exist in the model. The Radioss Engine was failing with segmentation fault.
  • /INISHE: correction of reading issue if several /INISHE cards are applied on the same component for specific model.
  • /LOAD/PBLAST:
    • Fixed scaled distance computed at initial time (Iz=1) which did not return the expected value with modified Friedlander model (Iform=2).
    • Improvement of the formulation Exp_data=2 and Exp_data=3 for specific models.
Contact interfaces
  • /INTER (Engine file): improvement of the card reading in case it is set to non-existing contact interface.
  • /INTER/TYPE2: stability improvement of the formulation Spotflag=27,28 with the option /PARITH/OFF.
  • /INTER/TYPE18: automatic estimation of the stiffness value is improved.
  • /INTER/TYPE24:
    • Correction of precision issue in the contact interface treatment for the solid to solid and edge treatment with single precision. More contact penetration can be seen on specific models.
    • Improvement of the edge to edge treatment cost.
  • /INTER/TYPE25:
    • Improvement of the edge to edge detection and reporting in the Starter output file.
    • Reduction of the memory usage and computation time for the contact interface in the Starter.
    • Improvement of the contact initialization at the beginning of the Engine.
    • Correction of /PARITH/ON issue.
Animation and Time History files
  • /ANIM/GPS/STRAIN/TENS or /H3D/NODA/GPSTRAIN: improvement of the output behavior when void property is set on solid elements.
  • /H3D/ELEM/DAMA: improvement of the output for SPH element to be displayed in the same output as the other elements.
  • /ATH: the part and total internal energy was not correct when /ATH card is defined in specific model computed with SPMD.
  • With the keyword "ELEM", the strain rate tensor for shell elements was not correctly output in the .h3d file.
    • /H3D/ELEM/TENS/EPSDOT/MEMB
    • /H3D/ELEM/TENS/EPSDOT/BEND
    • /H3D/ELEM/TENS/EPSDOT
    • /H3D/ELEM/TENS/STRESS
  • /H3D/NODA/GPS: correction of output issue in case material /MAT/LAW151 is defined in the model.
  • Contour was not assigned to some parts of specific models for /H3D/SHELL/FAIL and /ANIM/SHELL/FAIL.
  • /H3D/SHELL/TENS/.../PLY=ALL/NPT=ALL: correction for the tensor output of ply base composite material. The results were not correctly displayed for specific model.
  • /SECT: correction of the node/element connectivity definition for /PENTA6 to recover corresponding nodes and forces.