Slave and master surfaces

By default, contact pairs in Abaqus/Standard use a pure master-slave contact algorithm: nodes on one surface (the slave) cannot penetrate the segments that make up the other surface (the master), as shown in Figure 1. The algorithm places no restrictions on the master surface; it can penetrate the slave surface between slave nodes, as shown in Figure 1.

Figure 1. The master surface can penetrate the slave surface.

Due to the strict master-slave formulation, you must be careful to select the slave and master surfaces correctly in order to achieve the best possible contact simulation. Some simple rules to follow are:

  • the slave surface should be the more finely meshed surface; and

  • if the mesh densities are similar, the slave surface should be the surface with the softer underlying material.

The general contact algorithm in Abaqus/Standard enforces contact in an average sense between interacting surfaces; Abaqus/Standard automatically assigns master and slave roles.