A posteriori error analysis for Poisson's equation approximated by XFEM

International audienceThis paper presents and studies a residual a posteriori error estimator for Laplace's equation in two space dimensions approximated by the eXtended Finite Element Method (XFEM). The XFEM allows to perform finite element computations on multi-cracked domains by using meshes of the non-cracked domain. The main idea consists of adding supplementary basis functions of Heaviside type and singular functions in order to take into account the crack geometry and the singularity at the crack tip respectively