Superconvergence Analysis for the Stable Conforming Rectangular Mixed Finite Elements for the Linear Elasticity Problem

Abstract

In this paper, we consider the linear elasticity problem based on the Hellinger-Reissner variational principle. An $\mathcal{O}(h^2)$ order superclose property for the stress and displacement and a global superconvergence result of the displacement are established by employing a Clément interpolation, an integral identity and appropriate postprocessing techniques.