Altair Radioss 2019 Release Notes

Highlights

Radioss version 2019 offers a new multi-material for Arbritrary Lagrangian and Eulerian (ALE) applications. This material is compatible with all Equation of State (EOS), any fluid ALE material and can be used with brick or linear tetrahedron elements. This material uses a new Finite Volume Method solver which is simple to use, faster, more accurate and ensures energy conservation. The necessary boundary conditions, fluid structure contact interfaces and initialization options are available for this material law. This material is available for 2D axisymmetric and planar analysis with 3 node or 4 node solid elements. Also, new options are available to map results from 1D or 2D to 2D or 3D models for this new multi-material /MAT/LAW151.

Under water explosion (UNDEX) can now be computed using the Boundary Element Method (BEM). This option allows to compute quickly, without a fluid mesh, the pressure field on a wet surface structure subject to a far-field underwater explosion.

A new material based on the Barlat YLD2000 formulation is available for solid elements.

A new failure model with X-FEM for windshields based on the Christian Alter formulation is now available for shell elements. This material improves the accuracy of modeling failure in windshields.

Submodels can be defined inside other submodels and more options can be used in a submodel.

New Features

New ALE multi-material law using finite volume formulation and solver:
/MAT/LAW151 (MULTIFLUID)
Supported elements include:
  • 2D analysis with /TRIA and /QUAD elements
  • 3D analysis with /BRICK and /TETRA4 elements
Default boundary conditions are sliding wall.
Non-reflecting outlet and inlets can be used with new /EBCS/FLUXOUT and /EBCS/INLET options.
This material is compatible with:
  • /MAT/LAW5 and /MAT/LAW6
  • /ALE/MUSCL
  • /INIVOL
  • /INTER/TYPE1
  • /INTER/TYPE18
New features are available to initialize and define the boundary conditions of /MAT/LAW151:
/INIVEL/FVM
New option to define initial velocity in the parts defined with /MAT/LAW15
/EBCS/FLUXOUT
New non-reflecting outlet boundary condition
/EBCS/INLET
New inlet boundary condition
For 2D analysis with this material /MAT/LAW151, a new 3 node element is available:
/TRIA
New 3 node elements for 2D analysis
/GRTRIA
New set for /TRIA elements
New features to map 1D or 2D results on a 2D or 3D ALE mesh using /MAT/LAW151 (mono-material version only) or /MAT/LAW6:
/INIMAP1D
Map 1D velocities and thermodynamic values into 2D or 3D space by using spherical, cylindrical or planar mapping methods.
/INIMAP2D
Map 2D velocity and thermodynamic values into a 3D axi-symmetric space.
/FUNC_2D
Function to define a scalar value, or a vector value defined on a subset of R2.
Can be used only for the options /INIMAP1D and /INIMAP2D.
New features to simulate under explosion using boundary element method:
/BEM/DAA
Doubly Asymptotic Approximation for Underwater Explosion by Boundary Elements Method.
/BEM/FLOW
Incompressible Fluid Flow Computation by Boundary Elements Method.
Encrypting capabilities:
/ENCRYPT
New encrypting key option for the release of the HUMANETICS dummy models through Altair Partner Alliance Program.
Possibility to define an expiration date for the encrypted cards. After the expiration date, the model can no longer be used.
Can replace /KEY option.
Other new features:
/MAT/LAW187
New material based on Barlat YLD2000 formulation is available for solid elements.
/STATE/DT/ALL
New option to write all nodes of models and parts in the state file.
/FAIL/ALTER
New failure model for windshields with X-FEM.
//SUBMODEL
SUBMODEL can be defined in a SUBMODEL (with the same format and same unit system).

Enhancements

Material and failure models:
/MAT/LAW87
New flag Ifit=1 to be able to enter directly Lankford parameters 0°, 45°, 90° direction and biaxial loading.
/MAT/LAW25
New flag WP_fail=1 to be able to use W p max defined per direction when residual stress is smaller than yield stress.
/FAIL/TAB1 and /FAIL/EMC
Correction of the Lode angle calculation (for solids only).
Optimization:
/DVPREL1
Now supports /PROP/TYPE18 of /BEAM elements.
/DVPREL2
Now available for optimization.
Contact interfaces:
/INTER/TYPE24 (surface to surface contact)
Improvement of the cpu cost for specific models.
Improvement of the edge to edge behavior (I=1) for double and single precision versions.
Numerical issue correction with 3 nodes contact facet.
/INTER/TYPE2 (tied contact)
Kinematic motion improvement for tied contact with Spot=27 when shell is defined as slave and solid as master.
The Spot is reset to 0 when Spot=25, 27 and 28 in the contact interface TYPE2 whatever is input value.
Improvement of the tied contact with Spot=27 when thin shell elements are used as a skin to solid elements.
/INTER/TYPE25 (node to surface contact)
New feature I=2 to avoid self-impact within the same shell part in case the thickness is bigger than mesh size.
New feature I=3 to reduce the contact gap for shell parts based on mesh size.
Other cards:
/THERMAL
This option is now available for smooth particle hydrodynamic (SPH).
/SKEW/MOV and /FRAME/MOV
New option Dir to define the direction of the axis defined by nodes N1 and N2.
/ACTIV
New option T is available for I=2 formulation.
/H3D
The output of the /RBE2 was missing in the .h3d file.
Eroded tetrahedron elements are now correctly shown in the .h3d file.
/TH/INTER
Tangential force is now available for the drawbeads contact interface /INTER/TYPE8.
/TH/BRIC
Improvement of the output of the value DAMA for material law /MAT/LAW24.
/DT1TET10
This option calculates a more robust time step for 10-node tetrahedral /TETRA10.
This time step estimation is generally lower than the standard one, but may solve instability problems.
/REPORT/HTML
New option to create an .html report about the global parameters of the model and a global summary of the results.
/REPORT/MVW
New option to create an .mvw file with the basic information to understand the numerical validity of the results.

Resolved Issues

  • /PRELOAD: Improvement of the bolt section area computation. The preloading will better fit the input target force.
  • /SENSOR/RBODY: Correction of numerical issue on the activation time with the SPMD version.
  • /SUBDOMAIN: Numerical issue correction when this option is used with ALE materials and FSI contact interface TYPE18.
  • /INISHE/STRS_F: Correction of the unit conversion for the plastic strain (in case of several unit systems are used in the same model).
  • /DT/CST_AMS:

    Recommended scale factor values are now set as default values.

    Numerical issue correction when /DT/CST_AMS and /ANIM/ELEM/AMS are added in the model.

  • /RBE3: Numerical issue correction and element stability improvement for SPMD version.
  • /MONVOL: Error message improvement in the monitored volume checking.
  • /PROP/KJOINT2 (TYPE45): Element stability improvement when constant nodal time step is used with a time step scale factor of 0.9.
  • /PROP/SPR_GENE (TYPE8): Improvement of the error message when skew is referred in the property but not available in the model.
  • //SUBMODEL:

    Better support of the following options in a submodel: /SURF/SUBSET, /SPHCEL, /EREF, /AIRBAG1, and /COMMU1.

    The options /MAT/LAW73, /CONVEC, /SPHGLO, /SPHBCS, /GAUGE/SPH, and /TH/SPHCEL are now compatible with SUBMODEL.

  • /ALE/LINK/VEL: Numerical correction (Starter and Engine) when node identifiers are defined with more than 8 digits.
  • /BEGIN: Better error message if defined format is not a valid one.
  • /INTER/TYPE10: Numerical issue correction in the Engine with SPMD version and specific model.
  • /ATH and /ATFILE: Time history file format correction when /TH and /ATH are used together.
Radioss Starter improvements:
  • Improvement of the memory usage of Radioss Starter (decrease of the memory required for restart files writing).

    Simplification of the warning message when the number of SPMD domains is defined in the input using /SPMD and the command line.