Quasi-static contact problem with finitely many degrees of freedom and dry friction

A quasi-static contact problem is considered for a nonlinear elastic system with finitely many degrees of freedom. The friction law of Coulomb is used to model friction and the friction coefficient may be anisotropic and may vary along the surface of the rigid obstacle. Existence is established following a time-incremental minimization problem. Friction is artificially decreased to resolve the discontinuity arising from making and losing contact