Nonlinear Structural Materials Module Updates

For users of the Nonlinear Structural Materials Module, COMSOL Multiphysics® version 5.2a brings an extended Hyperelastic Material model with the ability to model large-strain viscoelasticity, as well as new material models for kinematic and isotropic hardening and the ability to mix these models for modeling elastoplastic materials. Review all of the Nonlinear Structural Materials Module updates in further detail below.

Large-Strain Viscoelasticity

The Hyperelastic Material models have been extended with the possibility to add viscoelasticity. The finite strain viscoelastic model has the same features as the one already available for small strains:

  • Generalized Maxwell, Standard linear solid, and Kelvin-Voigt models.
  • Williams-Landel-Ferry (WLF), Arrhenius, and User defined temperature shift functions.
By right-clicking the Hyperelastic Material model node, you can add a Viscoelasticity subnode.

By right-clicking the Hyperelastic Material model node, you can add a Viscoelasticity subnode.

By right-clicking the Hyperelastic Material model node, you can add a Viscoelasticity subnode.

Mixed Isotropic and Kinematic Hardening

For elastoplastic materials, hardening features have been extended to allow for arbitrary mixtures of isotropic and kinematic hardening in the Plasticity model. In previous versions, plastic hardening could only be described by either isotropic or kinematic hardening. By allowing mixtures of these two models, you can perform more realistic simulations of loading-unloading situations.
Settings for the Plasticity node with both the Linear isotropic hardening and Linear kinematic hardening models activated.

Settings for the Plasticity node with both the Linear isotropic hardening and Linear kinematic hardening models activated.

Settings for the Plasticity node with both the Linear isotropic hardening and Linear kinematic hardening models activated.

New Isotropic and Kinematic Hardening Models in Plasticity

Four new isotropic hardening models have been introduced to the Plasticity node:

  1. Ludwik
  2. Swift
  3. Voce
  4. Hockett-Sherby

Application Library path for an example that uses the new Ludwik model for isotropic hardening model for plasticity:

Fatigue_Module/Stress_Based/standing_contact_fatigue

Two new kinematic hardening models have been introduced to the Plasticity node:

  1. Armstrong-Frederick
  2. Chaboche