Mechanical APDL provides the following approaches for defining contact interactions:
Pair-based contact definition
General contact definition
Node-to-node contact elements
The pair-based contact definition and general contact definition both use surfaces to define contact. They are suitable for solving either small-sliding or large-sliding contact applications.
The node-to-node contact elements are often used in situations where the location of contact is known beforehand. These types of contact problems usually involve small relative sliding between contacting surfaces.
Each approach has unique advantages and limitations. In general, it is recommended that you use pair-based contact or general contact whenever possible.
A contact simulation using pair-based contact or general contact is defined by specifying the following:
Surface definitions for the bodies/parts that could potentially be in contact. The surfaces can be either deformable or rigid.
Contact pairing and interaction for the surfaces that interact with one another.
Contact interface behaviors such as friction coefficient. These are specified via MP and TB commands.
Contact properties and control parameters. These are specified via element real constants (R command).
Contact formulations and settings. These are specified via contact element key options (KEYOPT command).