Improving accuracy of opening-mode stress intensity factor in two-dimensional media using fundamental solution based finite element model

A hybrid finite element method (FEM) is developed for determining stress intensity factor of opening-mode cracks. The model is based on fundamental solutions and higher order displacement extrapolation. In the present formulation, linear combination of fundamental solutions and shape functions are respectively used to approximate the element interior and frame fields. The equality of the two approximations is enforced through a hybrid functional and element boundary integrals are involved only. Numerical examples are considered to investigate effects of element size, number of elements and crack length on crack tip singularity. Results show that the proposed approach can achieve better numerical accuracy than conventional FEM.