Finite-element analysis and structural optimization design study for cradle seat of CNC machine tool

Abstract

In order to improve the machining precision of the five-axis CNC machine tool, the cradle seat must have good structure and mechanical properties. Using the CAD/CAE-integrated design platform, static finite-element analysis and sensitivity analysis of the original cradle seat were conducted. Based on the above analysis, the weak part of the original cradle seat was discovered. A multi-objective optimization design process for the cradle seat’s weak part was carried out, and six groups of non-inferior solutions were obtained. From the six groups of optimization design schemes and the original design scheme, the optimal design scheme was selected using fuzzy matter-element method and the entropy-weight method. The cradle seat’s mass was reduced by 2.76%, and the maximum deformation was reduced by 27.38%. The impact test analysis results showed that the dynamic performance of the cradle seat, after optimization design, was greatly improved, which proves that the proposed structural optimization design method based on sensitivity analysis is reasonable and feasible.