UHARD

User subroutine to define the yield surface size and hardening parameters for isotropic plasticity or combined hardening models.

User subroutine UHARD:

  • is called at all material calculation points of elements for which the material definition includes user-defined isotropic hardening or cyclic hardening for metal plasticity;

  • can be used to define a material's isotropic yield behavior;

  • can be used to define the size of the yield surface in a combined hardening model;

  • can include material behavior dependent on field variables or state variables; and

  • requires, when appropriate, that the values of the derivatives of the yield stress (or yield surface size in combined hardening models) be defined with respect to the strain, strain rate, and temperature.

The following topics are discussed:

Related Topics
In Other Guides
Classical metal plasticity
Models for metals subjected to cyclic loading
*CYCLIC HARDENING
*PLASTIC

ProductsAbaqus/Standard