Release Notes > Nonlinear Structural Materials Module

Nonlinear Structural Materials Module
New Functionality in Version 5.2a
Large Strain Viscoelasticity
It is now possible to add Viscoelasticity to a Hyperelastic Material to simulate large strain viscoelastic applications.
Mixed Isotropic and Kinematic Hardening
The plasticity models have been updated so that isotropic and kinematic hardening models can be used simultaneously.
New Isotropic Hardening Models
The set of isotropic hardening models in plasticity has been extended with four new built-in models: Ludwik, Swift, Voce, and Hockett-Sherby.
New Kinematic Hardening Models
The kinematic hardening in plasticity has been extended with the Armstrong-Frederick and Chaboche models.
Time Derivatives of Plastic Strains
Time derivatives of the components of plastic strain are now available, so it is possible to use expressions like d(solid.epe,TIME) to create strain-rate-dependent plasticity models.
New Variables for hyperelastic strain energies
New variables have been added for incompressible hyperelastic material models: the volumetric and isochoric strain energy densities. The volumetric strain energy density is usually defined as <solid>.Wsvol, where <solid> is the tag of the Solid Mechanics interface where the Hyperelastic material node is defined. The isochoric strain energy density is defined as <solid>.Wsiso.
When using the Nearly incompressible formulation, the new variable <solid>.Uvol is defined as Wsvol was defined in previous versions. The variable Wsiso is now defined in terms of the auxiliary pressure <solid>.pw.
New variables for the isochoric second Piola-Kirchhoff stress tensor components have been added. These variables are derived from the isochoric strain energy density, and used in the definitions for large strain viscoelastic material models.