This section describes how you include user subroutines in a Nonlinear Structural Analysis or Thermal Analysis analysis. The following topics are covered:
Abaqus user subroutines can be used to extend the functionality of several capabilities in Nonlinear Structural Analysis or Thermal Analysis for which the usual data input methods may be too restrictive. User subroutines are written as FORTRAN code; during an analysis, Nonlinear Structural Analysis or Thermal Analysis refers to this code to calculate and define the specified properties or conditions. A subroutine must be compiled and attached to a model when you submit a job.
The following user subroutines are available in Nonlinear Structural Analysis or Thermal Analysis:
DFLUX
Defines a nonuniform and variable heat flux. For more information, see Creating Surface Heat Fluxes and Creating Body Heat Fluxes.
DISP
Defines a boundary condition magnitude that varies as a function of time and position. For more information, see Boundary Conditions and Boundary Conditions.
DLOAD or VDLOAD
Defines a pressure load magnitude that varies as a function of time and position. For more information, see Creating Pressure Loads.
FILM
Defines a nonuniform and variable film coefficient. For more information, see Creating Film Conditions.
FRIC or VFRIC
Defines shear transmission between contacting surfaces due to complex frictional behavior. For more information, see Creating a Mechanical Connection Behavior.
UTEMP
Defines a nonuniform and variable temperature history in Nonlinear Structural Analysis. For more information, see Creating Temperature Histories.
Before including a user subroutine in an analysis, you must compile the subroutine using the abaqus make utility. From a command line, execute the following command:
abaqus make library=source_file directory=destination
Source_file is the name of the user subroutine source file, and destination is the location to which the compiled subroutine object and shared library files will be written. When configuring a job in Nonlinear Structural Analysis or Thermal Analysis, you must specify the location of the compiled dynamic link library (.dll) file for the user subroutine (see Specifying File Storage Directories).
You can refer to only one compiled user subroutine file when you submit a job. If your model involves more than one user subroutine, you must combine the user subroutines and compile them into a single .dll file.