Abstract: It conducts multi-step optimization design of the weak structural member column based on the dynamic performance analysis of the entire machine tool. The column′s external structure and internal ribs are optimized using finite element method for the single column. The results show that the original rib pattern and distribution of the column have unreasonable design structures. Therefore,the column is topologically optimized,and the column's external structure and internal rib patterns are redesigned based on the data obtained from the dynamic performance analysis and the material distribution after topological optimization. The rib patterns and sizes are also analyzed for their parameter correlation,and a response surface optimization model is established. The Multi-Objective Genetic Algorithm (MOGA) (a variant of NSGA-Ⅱ) is used to optimize the key dimensions for multiple objectives,and the optimized entire machine is compared with the model to confirm the comes about. The comes about appear that the first-order common recurrence of the optimized column has expanded by 10.2 %;the maximum resonance peak in the X direction has decreased by 15 %,in the Y direction by 25 %,and in the Z direction by 54 %. Furthermore,the wave peaks in the X and Y directions have been shifted back to some extent. Therefore,the optimized machine tool has improved its static and dynamic performance.

Key words: pillar, rib pattern, finite element method, topology optimization, multi-objective parameter optimization