An a posteriori error estimator for the Lamé equation based on equilibrated fluxes

Abstract. We derive a new a posteriori error estimator for the Lame system based on H(div)-conforming elements and equilibrated uxes. It is shown that the estimator gives rise to an upper bound where the constant is one up to higher order terms. The lower bound is also established using Argyris elements. The reliability and eciency of the proposed estimator is conrmed by some numerical tests. Key words. equilibrated uxes, mixed nite elements, a posteriori error estimates, linear elasticity AMS subject classications. 65N30, 65N15, 65N50 1. Introduction. Th