Bionic optimization design for a CNC turntable based on thermal–mechanical coupling effect

During the machining process, the thermal–mechanical coupling effect of CNC turntable is produced by the action of variable loads and various heat sources. In order to improve the static and dynamic characteristics under thermal–mechanical coupling effect, a novel bionic optimization design method for CNC turntable was proposed. The finite element modal analysis on a CNC turntable was carried out to obtain the weak link of its dynamic characteristics, and the thermal–mechanical coupling analysis on the CNC turntable was conduct to reveal the influence of the thermal–mechanical coupling effect on the dynamic characteristics of the CNC turntable. In view of the good mechanical properties of Victoria amazonica, bionic design for the CNC turntable was carried out based on the strong similarity of structure and function. The optimization objectives and design variables of bionic CNC turntable were selected according to the thermal–mechanical coupling and modal analysis results, and the influence law of the design variables on the optimization objectives was studied by sensitivity analysis method. The optimal solution to bionic CNC turntable was obtained through response surface optimization, which made the maximum deformation was reduced by 2.37%, the mass was reduced by 15.60%, and the first six order natural frequencies were increased. The feasibility of the proposed bionic optimization design method for CNC turntable was verified through comparing the first six order natural frequencies of modal experimental results with optimization results. Therefore, the bionic optimization method provides a new idea for structural design of CNC machine tools’ parts to improve the static and dynamic characteristics.