This chapter discusses additional user programs that can be run with Abaqus. It provides an overview of the following enhancements:

• “User-defined friction coefficient for contact surfaces,” Section 13.1

• “User-defined frictional behavior for contact surfaces,” Section 13.2

• “User-defined interaction between contact surfaces,” Section 13.3

• “User-defined viscosity,” Section 13.4

• “Accessing the Abaqus material library from user subroutine UELMAT,” Section 13.5

• “User-defined Eulerian materials,” Section 13.6

• “Enhancements to the Really Simple GUI plug-in,” Section 13.7