Abstract

We present an a posteriori error estimation based on a equilibrated H(div)-conforming stress reconstruction for unilateral contact problems without friction, discretized with a Nitsche-based method. The stress reconstruction is obtained via local Neumann problems constructed on Arnold-Falk-Winther mixed finite element spaces, and it is used to compute some local and global estimators which separate the different components of the computational error. These local estimators provide a method to adaptively refine the mesh.