Optimization Design Methods To Reduce Weight For Parts Of Machine Tools

Machine tool industry is the basic to revitalize national industry. Because the machine tools are composed of several parts, researching how to improve the performance of the parts, especially the moving parts, could result to enhance the performance of the machine tools. Currently, the core approach to make the parts better is weight-optimization. Weight-optimization that is arranging the material under the guide of thesis to make the structure reasonable and light is carried out, with ensuring the process accuracy of the machine tools, to save the resources and energy and raise the process efficiency, which are the trends of the tools. The main the paper follows:(1) The paper elaborates the shape and the working principle of the worktable in the case of overall design of structures&materials. The CAD model of the worktable is simplified and transformed to a CAE model. With the CAE model, the paper gives out the static analysis result, modal analysis result and resonance analysis result of the worktable. According to the results, the worktable’s displacement emerges mainly in Z direction of the tool under the static force, the first and second modal of the worktable would be harmful to the accuracy of the tool.(2) Overall Design Structures&Materials is proposed. With this design method, referring the structure of the metal-foam sandwich panel at the same time, the weight optimized design comes out. From design principles, the whole design, reinforced design, structure for process design and process design, the paper shows the procedure of how to realize the weight optimization of the worktable. The redesigned worktable is analyzed by static analysis, modal analysis, resonance analysis, which are compared with the results of the original-design. The contrast shows that the redesigned worktable’s performance under static force is nearly not changed, the first modal in the original-design that is the most harmful to the process accuracy of the tools is disappeared and the frequencies of other modal are raised. The most important is the improvements are brought about while the weight of the worktable is decreased by15.6%. The research proves the design method, overall design structures&materials, is useful to weight optimized design in the machine tools industry.(3) There is a new kind of optimization is put forward. Assumed the tools equipped with CNC Compensation System, then increasing the structural stiffness is meaningless to promise the process accuracy of the tools. At the moment, the structure should be requested to serve the CNC Compensation System and be designed that the displacements the core region would be as uniform as possible instead of the structural stiffness. If the structural stiffness is not requested the less material will be needed and the weight optimization will go further. To quantitatively describe the degree of the uniformity of the displacements come out in the core region, the concept named Displacements Dispersion is proposed. And the optimization is called Displacements Dispersion Optimization (short as DDO). The paper also give out the mathematical essence of the DDO and the variant equation for optimization solution. To research the DDO, some examples are computed in the paper, including cantilever in1D, beam fixed at both ends in1D, four-terminal fixed plate in2D, deep beam with small width fixed at both ends in2D.There conclusions are got from the researches as follow.1) Compared with Maximizing Stiffness Optimization the results of the DDO show little low structural stiffness, and the displacements dispersion is highly raised, especially in the deep beam with small width fixed at both ends in2D example;2) At the same optimized area, without the depth of the structure, the results of the symmetrical structure’s DDO are influenced by load equivalent center, not the range of load;3) The DDO is affected majorly by the select of the optimized area and a reasonable optimized area would bring a reasonable design;4)when the structure is with depth, selecting more area in the deep direction will ameliorate the optimization results, etc.(4) The worktable model is topology-optimized by Maximizing Stiffness Optimization, DDO, a combination of both, and this work points that DDO could be used in3D optimized design just like the Maximizing Stiffness Optimization to realize the weight-loss of the structure.