The mortar method with approximate constraint: a flexible tool for coupling hetherogeneous discretizations

In the framework of an object oriented implementation we compare the classical version of the mortar method with a version where the weak continuity constraint is imposed in an approximate form via a projection on an auxiliary space. We aim at showing the advantages of the latter in terms of flexibility and easy extendibility of the code. In particular, we show that the new technique allows to handle the subdomains of the decomposition as independently as possible and to integrate new types of discretization schemes without any modification to the fragments of the code already implemented for the standard approach.