关键词: 折弯机, 结构优化, 响应面法, 轻量化, 非支配排序遗传算法Ⅱ

Abstract: Aiming at the structural optimization problem of a 100 t hydraulic sheet metal bending machine,a response surface and NSGA-Ⅱ collaborative multi-objective optimization design method for the bending machine was proposed. A parametric model was established to analyze key design variables,including frame thickness,rib plate spacing,and slider cross-sectional height. Utilizing Central Composite Design (CCD) method,15 experimental samples were generated to systematically investigate the nonlinear coupling relationships between these design variables and critical performance metrics including machine mass,deformation,and stress. The NSGA-Ⅱ algorithm was subsequently applied to optimize the trade-offs among mass reduction,deformation control,and stress constraints. Post-optimization results demonstrate a 7.1 % reduction in machine mass and a 20.0 % decrease in maximum deformation,significantly improving lightweight performance and structural stiffness. Although the maximum stress increased by 50 %,it remained below the yield strength of Q235 steel. The findings validate that the proposed methodology effectively balances lightweight design,stiffness enhancement,and strength requirements for bending machines. This research confirms the engineering applicability of response surface methodology in multi-objective optimization of complex mechanical systems and provides a theoretical foundation and technical pathway for designing high-precision sheet metal processing equipment.

Key words: bending machine, structural optimization, response surface methodology, lightweighting, Non-dominated Sorting Genetic Algorithm-Ⅱ(NSGA-Ⅱ)