Abaqus User Subroutines Guide

The Abaqus User Subroutines Guide describes all the user subroutines available for use in Abaqus analyses and the utility routines that can be used when coding subroutines.

This guide is a part of the Abaqus® documentation collection, which describes all the capabilities of the Abaqus finite element analysis technology used in SIMULIA® applications.

User subroutines:

  • are provided to increase the functionality of several Abaqus capabilities for which the usual data input methods alone may be too restrictive;

  • provide an extremely powerful and flexible tool for analysis;

  • are written as C, C++, or Fortran code and must be included in a model when you execute the analysis, as discussed below;

  • must be included and, if desired, can be revised in a restarted run, since they are not saved to the restart files);

  • cannot be called one from another; and

  • can in some cases call utility routines that are also available in Abaqus.

A variety of utility routines are available to assist in the coding of user subroutines. You include the utility routine inside a user subroutine. When called, the utility routine will perform a predefined function or action whose output or results can be integrated into the user subroutine. Some utility routines are only applicable to particular user subroutines.

For information about the abaqus make utility, which is used to create user postprocessing executables and user-defined libraries of Abaqus user subroutines, see Making User-Defined Executables and Subroutines.

Most user subroutine interfaces in this guide use the Fortran language, although user subroutines can be written using the C and C++ languages. Similarly, the utility routines can be invoked from within these C and C++ user subroutines. For more information, see Writing a User Subroutine and the Knowledge Base item QA00000008005 in the Dassault Systèmes Knowledge Base at QA00000008005.