中文摘要：

轿车车身轻量化设计是一个多约束的复杂系统优化问题,且必须满足各项车身结构性能,其中碰撞安全性是先决条件。实际中普遍采用试验设计和响应面法相结合的手段开展轻量化研究。针对传统响应面法拟合约束函数易引起优化解落在非可行域内的缺陷,提出一种面向不等式约束函数的改进响应面法,使近似约束边界分布在可行域中,得到能够满足设计约束的优化解,数值算例验证了改进响应面法在处理约束优化问题中具有比传统响应面法更为明显的优势。将其应用到车身轻量化设计中,结果表明,基于本研究提出的改进响应面法的轻量化方案优于传统响应面法,整车耐撞性能得到提高的同时实现车身前部结构减重21.4%,为开展车身轻量化设计研究提供可借鉴的方法。

英文摘要：

Lightweight design of autobody is a complex optimization problem with multiple constraints,in which vehicle crashworthiness is the most critical requirement.It is a common approach to integrate design of experiment with response surface method（RSM） for structural optimization.While RSM is used to approximate the constraint function,the optimal solution is inclined to locate in the unfeasible region.Therefore,an improved response surface method（IRSM） is proposed.It puts the boundary constraint of approximate model to the feasible region,so that the optimal solution can meet the design condition.IRSM is demonstrated to be better than traditional RSM for constraint optimization problem through numerical experiment.Then it is employed to lightweight design of autobody and the results illustrate that the optimal solution than that from IRSM is better than RSM.It reduces structure weight by 21.4% with the improvement of vehicle crashworthiness simultaneously.It is demonstrated that IRSM,as an effective approach to constraint function approximation,can be used for future studies on autobody lightweight design.