Abstract:

A roof structural crashworthiness design method was proposed and implemented in a vehicle roof structural design,which aimed at the cost and efficiency in the application of high strength steel in vehicle
 body structural design.First,the global sensitivity analysis was carried out to choose the prominent components.Then the material type and thickness of the prominent components were treated as discrete and continuous design variables,respectively.Considering the weight and material cost,a mathematical model of the roof structural crashworthiness optimization was established.The moving least square response surface and genetic algorithm,in conjunction with Latin hypercube sampling method,were utilized to maximize the maximum impact force of the roof.The results show that the roof strength is enhanced by 18.53% with the vehicle weight and material cost controlled.The present method offers an efficient way for the selection of high strength steel in the structural optimization for roof crashworthiness design.

Key words: roof strength, structural crashworthiness, sensitivity analysis, optimal design, high strength steel, cost control

摘要：

针对高强度钢在车身结构设计中的应用成本与效率问题，提出一种车顶结构耐撞性设计方法，并对某车型进行优化设计。首先进行全局灵敏度分析，筛选出影响车顶强度的主要承载部件;然后将高强度钢的选型作为离散设计变量,厚度作为连续设计变量，同时对材料成本和总质量进行约束，建立车顶结构耐撞性优化的数学模型;最后，采用移动最小二乘法构造近似模型，结合遗传算法对主要承载部件进行优化设计。结果表明：在部件总质量和材料成本的控制下,车顶承载能力提高18.53%。该方法为高强度钢在车顶结构耐撞性优化设计中的应用提供了一种选型参考。

关键词: 车顶强度, 结构耐撞性, 灵敏度分析, 优化设计, 高强度钢, 成本控制