Superconvergent extraction of flux intensity factors and first derivatives from finite element solutions Original Research Article

A superconvergent method for the computation of the derivatives of the solution and the coefficients of the asymptotic expansion at singular points is presented for the Laplace problem in two dimensions. The algorithm utilizes the complementary weak form on a localized small domain. Mathematical analysis demonstrates the superconvergent behavior, and numerical experiments support our analysis. This method is well suited for anisotropic multi-material singular interface problems.