Abstract:A treatment technique for modeling 3D discontinuous interfaces in elastic bodies by the element-free Galerkin method is presented. In this technique,the isolation effect of discontinuous interface on domain of influence for a Gauss point is dealt by visibility criterion,and contribution of reciprocity between the two faces of discontinuous interface to the system of equilibrium equations is considered. The contributive equation of discontinuous interface to the system of equations is derived and nonlinear iterative algorithms for simulating the contact state of a discontinuous interface are studied. An element-free analysis program for simulation of three-dimensional discontinuous interfaces is developed on basis of the aforesaid discussion. Finally,the program is applied to analyze a cracked cube under the action of well-distributed stress. The result shows that the method and program presented in this paper are reliable and feasible.