Adaptive Quadratic Finite Element Method for the Unilateral Contact Problem

In this paper, we present and analyze a posteriori error estimates in the energy norm of a quadratic finite elementmethod for the frictionless unilateral contact problem. The reliability and the efficiency of a posteriori error estimator is discussed. The suitable decomposition of the discrete space V-h (0) and a discrete space Qh, where the discrete counterpart of the contact force density is defined, play crucial role in deriving a posteriori error estimates. Numerical results are presented exhibiting the reliability and the efficiency of the proposed error estimator.