In order to make a 5-axis linkage horizontal machining center have better dynamic characteristics, considering the influence of joint surface, dynamic characteristic analysis is conducted to the machining tool. Based on finite element modal analysis results, the weak link is found and optimized. Through the finite element calculation and analysis, the structure rigidity obviously raises after optimization. This offers a new idea on how to improve the rigidity of complete machine of machining tool for later research.

To design a milling machine with high static stiffness and machining precision, the three-dimensional (3-D) model and the finite element model of a large-scale high-speed gantry type CNC milling machine have been established according to the demand of engineering. The main components of the milling machine have been studied separately by static and dynamic analysis to make an optimal structure design. The results indicate that the structure of the milling machine has great static stiffness, little structural deformation, and good dynamic characteristics. The method used in this paper provides helpful theoretical guidance to the dynamic design of milling machine.