Derivative Superconvergence of Equilateral Triangular Finite Elements

摘要

Derivative superconvergent points under locally equilateral triangular mesh for both the Poisson and Laplace equations are reported. Our results are conclusive. For the Poisson equation, symmetry points are only superconvergent points for cubic and higher order elements. However, for the Laplace equation, most of superconvergent points are not symmetry points, which are reported for the first time in the literature.