APPROXIMATION OF THE UNILATERAL CONTACT PROBLEM BY THE MORTAR FINITE-ELEMENT METHOD

The purpose of this Note is to extend the mortar finite element method to handle the unilateral contact model between two deformable bodies. The corresponding variational inequality is approximated using finite elements with meshes which do not fit on the contact zone. The mortar technique allows us to match (independent) discretizations within eac h solid and to express the contact conditions in a satisfying way. The n, we carry out a numerical analysis of the algorithm and, using a boo tstrap argument, we give an upper bound of the convergence rate simila r to that already obtained for compatible grids.