Abstract：Using the theory and implementation technology of two dimensional element-free method as a reference，this paper presents a three dimensional element-free method using moving least squares approach based on orthogonal basis functions. The treatment of the essential boundary conditions，derivation of governing equations and implementation algorithms are also discussed. A program of three dimensional element-free method is developed and is applied to analyze the deformation of a pillar under the action of dead weight. Comparison bewteen the calculated numerical results and the exact solution shows that the method and program presented in this paper are reliable.
