Superconvergence and extrapolation analysis of ACM finite element methods for nonlinear viscoelasticity equation

In this paper, ACM finite element method is applied to the approximation of nonlinear viscoelasticity equation for the semi-discrete scheme. by the integral identity, averaging technique and interpolated post processing techniques, the superclose and the global superconvergence properties with order O(h^3.5) are derived. Furthermore, through constructing a suitable extrapolation scheme, higher accuracy of extrapolation solution is obtained. The results proposed in the paper are the same as that of the linear case in the previous literature.