Abstract

A collaborative optimisation method for the lightweight and crashworthiness of the cab structure is proposed using mixed variable screening, approximate models, multi-objective optimisation and ideal point methods. First, modal and stiffness analyses of the cab model are built. Three impact simulation model of cab are established and verified via ECE R29-02 regulation tests. Subsequently, front impact, front pillar impact, and roof strength model are established following ECE R29-03, which is more stringent than the ECE R29-02. However, the result of the front pillar impact of the cab does not meet the requirements of the ECE R29-03. Several improved A-pillar structures are proposed, among which reinforced rib structure can effectively enhance the occupant’s living space. Then, 18 thickness and 4 material variables are selected as design variables based on the mixed variable screening method. Different approximate models are established for performance responses. The results show that the second-order response surface model has high fitting accuracy in the cab modal and bending and torsional stiffness performance, while the Kriging model has high fitting accuracy in the crashworthiness indicators of the cab. Finally, the multi-objective lightweight and crashworthiness collaborative optimisation of the cab are conducted. Compared with the initial model, the crashworthiness of the optimal cab model is improved and the mass is reduced by 27.1 kg.

摘要

提出了一种混合变量筛选、近似模型、多目标优化和理想点法的驾驶室结构轻量化和耐撞性协同优化方法。首先，建立了驾驶室模型的模态和刚度分析。三种驾驶室冲击仿真模型的建立与验证ECE R29-02 法规测试。随后按照ECE R29-03建立了前碰撞、前柱碰撞和车顶强度模型，比ECE R29-02更严格。但驾驶室前柱撞击结果不符合ECE R29-03的要求。提出了几种改进的A柱结构，其中加强筋结构可以有效提升乘员的居住空间。然后，基于混合变量筛选方法选择18个厚度和4个材料变量作为设计变量。为性能响应建立了不同的近似模型。结果表明，二阶响应面模型在驾驶室模态和弯扭刚度性能方面具有较高的拟合精度，而克里金模型在驾驶室耐撞性指标上的拟合精度较高。最后，对驾驶室进行了多目标轻量化和耐撞性协同优化。与初始模型相比，优化驾驶室模型的耐撞性提高，质量减轻了27.1 kg。