© 2001 by Oxford University Press
Variational and Numerical Analysis of a Frictionless Contact Problem for ElasticViscoplastic Materials with Internal State Variables
( 1 Departamento de Matemática Aplicada, Universidade de Santiago de Compostela, España 2 Department of Mathematics, University of Iowa, Iowa City, IA 52242, USA 3 Laboratoire de Théorie des Systèmes, Université de Perpignan, France 4 Departamento de Matemática Aplicada, Universidade de Santiago de Compostela, España )
We consider a quasistatic frictionless contact problem between a deformable body and a foundation. The material is assumed to have a nonlinear behaviour that we model with a rate-type viscoplastic constitutive law involving internal state variables. The contact is modelled with normal compliance. We present a variational formulation of the problem and prove the existence and uniqueness of the weak solution. We then derive error estimates for a fully discrete scheme to solve the problem. Under appropriate regularity assumptions on the exact solution, we establish optimal-order error estimates. Finally, we present numerical examples which show a very good performance of the fully discrete scheme.