A stiffener structural design method for worktable of heavy-duty vertical lathe by combining modal analysis and topology optimization

The structural design for worktable stiffeners plays an important role in determining dynamic characteristic of heavy-duty vertical lathe which directly affects the machining performance. In this paper, a stiffener design method for worktable stiffeners combining modal analysis and topology optimization is proposed to improve the static and dynamic performances. The dynamic characteristics of worktable are analyzed by modal analysis, and the weak part of the worktable base is determined by combining the results of modal analysis and vibration signal processing. An initial optimal structure of the worktable base is obtained by solid isotropic material with penalization (SIMP) based on topology optimization. Then, the layout of stiffeners is remodeled according to the initial optimal structure by number and size optimization. Finite element analyses are implemented to evaluate the performance of the newly designed structure. The natural frequency of the worktable base is increased by 7.59% with a decrease of 11% in the mass. Experiments are carried out to verify the validity of the proposed stiffener design method. The experimental result also shows that the natural frequencies of the worktable base have increased by more than 10%.