Materials and Properties

Within this section supported materials are discussed.

Materials Allowed in Topology Optimizations

All linear, some non-linear constitutive and anisotropic material laws for Abaqus are supported as design elements:

  • Linear-elastic, isotropic material 
    *ELASTIC, TYPE=ISOTROPIC
  • Linear-elastic, anisotropic material 
    *ELASTIC, TYPE=ENGINEERING CONSTANTS
*ELASTIC, TYPE=LAMINA
*ELASTIC, TYPE=ORTHOTROPIC
*ELASTIC, TYPE=ANISOTROPIC
    not supported as design element: 
    *ELASTIC, TYPE=TRACTION
*ELASTIC, TYPE=COUPLED TRACTION
  • Hyperelastic:

    Some material cards of *HYPERELASTIC are supported as design elements, see also the figure below. 

     ARRUDA-BOYCE
 MOONEY-RIVLIN
 NEO HOOKE
 OGDEN
 POLYNOMIAL
 REDUCED POLYNOMIAL
 VAN DER WAALS
 YEOH
    Not supported as design elements: 
     MARLOW
 USER
    Using TEST DATA INPUT parameter in *HYPERELASTIC (that is usually followed by *UNIAXIAL TEST DATA or other test data) is not allowed.

  • The material card *PLASTIC is supported as design element, see also the figure below. Supported for the type HARDENING=ISOTROPIC (default). A main limitation is that each material point (gauss point) is only allowed to be unloaded once and it should not be elastoplastic again. Meaning that cyclic loading is not supported.
  • *CONCRETE is supported for design elements
  • The material card *HYPOELASTIC is support as design element, see also figure the following figure .
Some of the *PLASTIC (a), *HYPOELASTIC (b) and *HYPERELASTIC (c) cards in Abaqus are supported for design elements.
  • Dependency of temperature or other field variables (Parameter DEPENDENCIES).

Materials Allowed in Shape Optimization

  • All linear and non-linear elastic materials:
  • *ELASTIC
*HYPERELASTIC
*HYPERFOAM
*HYPOELASTIC
*POROUS ELASTIC
  • Plasticity
  • Dependency of temperature or other field variables (Parameter DEPENDENCIES).

Shell property definition limitation

For topology and sizing optimization only uniform shell thickness is allowed for design-domain element. The following section assignment for a design domain element(s) in topology or sizing optimization will cause an abort

*SHELL SECTION, NODAL THICKNESS = ...
*SHELL SECTION, SHELL THICKNESS = ...

Remark

The use of nonlinear materials in an optimization is only permitted for users of the SIMULIA Tosca Structure.nonlinear license. This applies for the commands and parameters below:

*CONCRETE
*HYPERELASTIC
*HYPERFOAM
*HYPOELASTIC
*PLASTIC
*POROUSELASTIC
*VISCOELASTIC

If no license is held for this mode, the optimization stops once the parameters or commands listed above are used. This does not apply if a linear perturbation step is used.