In ABAQUS/Standard you can introduce dependence on solution variables with user subroutine USDFLD. This subroutine allows you to define field variables at a material point as functions of time, of any of the available material point quantities listed in “ABAQUS/Standard output variable identifiers,” Section 4.2.1 of the ABAQUS Analysis User's Manual, and of material directions. Material properties defined as functions of these field variables may, thus, be dependent on the solution.
User subroutine USDFLD is called at each point for which the material definition includes a reference to the user subroutine. For more information, see “USDFLD,” Section 1.1.40 of the ABAQUS User Subroutines Reference Manual.
To include a reference to user subroutine USDFLD in a material definition:
From the menu bar in the Edit Material dialog box, select General
User Defined Field.
(For information on displaying the Edit Material dialog box, see “Creating or editing a material,” Section 12.6.1.)
Click OK to close the Edit Material dialog box. Alternatively, you can select another material behavior to define from the menus in the Edit Material dialog box (see “Browsing and modifying material behaviors,” Section 12.6.2, for more information).