基于全局响应面法的镁合金客车骨架优化设计

Optimization design of magnesium alloy bus frame based on global response surface method

为了解决纯电动公交客车质量较重、续航里程低的问题,采用轻量化效果更显著的镁合金材料作为客车车身骨架并进行结构优化设计,应用部分因子设计法进行相对灵敏度分析并筛选设计变量,以整车骨架弯曲刚度和扭转刚度为约束条件,以整车骨架重量最小、一阶扭转频率最大为目标函数,构建径向基函数近似模型,采用全局响应面算法进行尺寸优化。优化结果表明,在保证结构性能的前提下,骨架重量与原整车骨架相比减轻了799 kg,减重率达22.8%,轻量化效果显著。

In order to solve the problem of heavy weight and low endurance of pure electric bus, magnesium alloy material with more obvious lightweight effect is adopted as the bus body framework and structural optimization design is carried out. Partial factor design method is applied to carry out relative sensitivity analysis and screen design variables. The bending stiffness and torsional stiffness of the bus framework are taken as constraints, and the minimum weight of the bus framework and the maximum first-order torsional frequency are taken as objective functions, then the radial basis function approximation model is constructed, and the global response surface algorithm is used to optimize the size. The optimization results show that, on the premise of ensuring the structural performance, the weight of the frame is reduced by 799 kg compared with the original vehicle frame, with a weight reduction rate of 22.8%, and the lightweight effect is significant.