摘要
For rectangular finite element, we give a superconvergence method by SPR technique based on the generalization of a new ultraconvergence record and the sharp Green function estimates, by which we prove that the derivative has ultra-convergence of order O(hk+3) (k 3 being odd) and displacement has order of O(hk+4) (k 4 being even) at the locally symmetry points.
For rectangular finite element, we give a superconvergence method by SPR technique based on the generalization of a new ultraconvergence record and the sharp Green function estimates, by which we prove that the derivative has ultra-convergence of order O(h k+3) (k ? 3 being odd) and displacement has order of O(h k+4) (k ? 4 being even) at the locally symmetry points.