Abstract: Taking the giving character of cutting tool and special material (7050-T7451) as object, using the milling force model which comes from the milling experiment as the boundary conditions of FEM, the main factors, I.e. the residual stress, which affects the dimension stability and distortion of the finished parts are analyzed. Then, the mathematical model contacting the residual stress with milling parameters is founded. In the course of analysis, the idea of kill-elements is introduced to simulate the material removing, and considering the impaction of cutting tool as soon as it cuts in the parts, the instant mechanics characteristic of the cutting tool contacting parts is simulated by micro-time steps, so that ensure the analysis result be more actual.

Key words: FEM, Impaction effect, Milling force, Residual stress