Bionic optimization design for the crossbeam of a five-axis machining center based on honeycomb sandwich structures

In order to improve the static and dynamic performance of the crossbeam of five-axis machining centers, a bionic optimization design method based on honeycomb sandwich structures was proposed. The finite element model of a crossbeam was established, and the static and dynamic performance indexes were analyzed. In order to obtain the honeycomb sandwich bionic structure crossbeam, the crossbeam sizes with high static and dynamic performance correlations were obtained using the sensitivity analysis method, and the bionic design for the original crossbeam was carried out based on honeycomb sandwich structures. To select the honeycomb sandwich bionic structure crossbeam with excellent performance, the weight of each index of the total performance of the crossbeam was determined using the analytic hierarchy process, and the variation formula of the total performance of the honeycomb sandwich bionic structure crossbeam was constructed. To obtain the excellent size of the honeycomb sandwich bionic structure crossbeam, the response surface optimization was carried out on the honeycomb sandwich structure crossbeam using the central composite test design method. To select the best candidate points of optimization scheme, the formula for the total performance variation of the crossbeam of the optimized honeycomb sandwich bionic structure was constructed using the analytic hierarchy process. The results show that compared with the original crossbeam, the optimized bionic crossbeam has a small reduction in mass, its maximum total displacement is reduced by 10.16%, its maximum equivalent stress is reduced by 27.61%, its first-order natural frequency is increased by 2.47%, and its second-order natural frequency is increased by 4.85%. The optimization results show that the lightweight of the crossbeam is achieved and its static and dynamic performance is improved, thus proving that the proposed bionic optimization design method based on the honeycomb sandwich structure is reasonable.