| With the development of high-speed precision modern machine tools, it needs to have good dynamic and static behaviors. Therefore, the research on the dynamic and static behavior of machine-building industry has been one of the important steps.In this paper, the research object is the XM18 spherical generator, in order to improve the dynamic behavior of the machine tool, the following aspects have been studied in this thesis:Firstly, based on the elasticity theory and finite element analysis theory, the finite element models of the lathe bed, dovetail, dovetail shelf, headstock, fanlike plank and millhead shelf, which were the main parts of the spherical generator, were built up using ANSYS9.0. And based on the modal analysis theory and FEM technology, the free modal and the constrained modal analysis of the main parts were studied. Accordance to the analytical results, put forword methods to optimize the key parts.Secondly, the equivalent dynamic characteristics parameters of bolt joints were researched, and the finite element model of the combined frame was built up using the linear spring-damper elements. Then the free modal, the constrained modal and the static analysis were studied in different working situations.Thirdly, the modal parameters of the spherical generator were identified according to the results of the modal test. These were compared with the results of the finite element modal analysis, and the correctness of the finite element model of the combined frame was confirmed.Lastly, based on the sensitivity analysis technology and structure optimization design method, sensitivity analysis and optimization design of the lathe bed and headstock, which were the key parts of the spherical generator, were studied using Pro/MECHANICA STRUCTURE. Based on the Optimum result, the free modal, the constrained modal and the static verify of the modified combined frame were studied in different working situations. The analysis results not only improve the intensity and stiffness, but also effectivly avoided resonates. |
