10.5 The Rigid Boundary Condition

As noted above, rigid bodies don't require geometry (except when used in contact) and are implicitly defined via rigid body materials. In order to tie a deformable body to a rigid body, a special boundary condition, the rigid boundary condition, is used. The rigid boundary condition is added as any other boundary condition (e.g. via the menu Physics → Add Nodal BC). Any selection of a deformable object (e.g. surface) that is assigned to this boundary condition will be tied to the rigid body. The rigid body that the selection ties to, is set as a parameter of the rigid boundary condition.

The rigid boundary condition should not be used to tie two rigid parts together. The easiest way to tie rigid parts together is to assign them the same rigid body material.