Page History

...

Next we list the relevant boundary conditions of our problem.  The two types of boundary conditions, essential and natural, will be specified for all boundaries in our model.  It must be noted that essential boundary conditions refer to displacement conditions and natural boundary conditions represent traction conditions.  It is also important to observe that only one of these boundary conditions may be specified at a given boundary.  In addition, only one of these boundary conditions is sufficient for a given boundary point.

Along the frictionless contact interface, we specify the following boundary conditions.

...