A Quasistatic Contact Problem for an Elastoplastic Rod

We consider a mathematical model which describes the quasistatic contact of an elastoplastic rod with an obstacle. It is based on the Prandtl]Reuss flow law and unilateral conditions imposed on the velocity. Two weak formulations are presented and existence and uniqueness results established. The proofs are based on approximate problems with viscous regularization, which have merit on their own and may be used as the basis for convergent numerical algorithms for the problem