Paper Title
A Quasistatic Evolution of Rate-Type Viscoplastic Materials without Internal State Variables

Abstract
In this paper, we study two initial and boundary value problems describing the Quasistatic evolution of rate-type viscoplastic materials with without internal state variables submitted to contact boundary condition. Variationnel formulations are given and, using a Cauchy-Lipschitz technique, the existence and uniqueness results are obtained. Finally, the numerical approach of the solution is studied and a concrete algorithm based on an Euler method is proposed. The theoretical results presented here are completed by two numerical examples and the advantages of these new proofs respect to the ones cited in the paper are commented. . Keywords - Existence of solution, Monotony Method, Quasistatic processes, Viscoplastic Materials