大客车侧翻安全性多目标优化

建立某大客车的侧翻有限元模型,仿真结果表明,其初始设计无法满足侧翻法规要求,需要进行优化设计。为克服碰撞分析的高度非线性给优化造成的困难,结合均匀实验设计、响应面方法和逐步回归技术建立该客车的侧翻响应面替代模型,并以车体质量最小,车身结构吸能最大为目标函数,以满足侧翻法规为约束条件,采用NSGA-II算法进行多目标优化设计。对优化方案进行有限元仿真验证,结果表明,优化方案不仅使该客车满足了ECE R66法规的要求,而且减小了车体总质量,同时增加了车身结构的吸能,有效地提高了侧翻安全性。

Multi-objective Optimization for Bus Rollover Crashworthiness

Finite element model of a bus rollover was established,whose simulation results show that the initial design could not pass the ECE Regulation No.66.Therefore,the bus structure needs to be optimized.To overcome the difficulties of high nonlinearity of crashworthiness analysis in optimization,the surrogate models of rollover responses were established by combing with uniform design of experiments,response surface method and stepwise regression techniques.A multi-objective optimization was implemented by NSGA-II,in which the objectives are to minimize the weight of the bus body and to maximize the absorbed energy of the bus frame,and the constraints are to meet the regulation of rollover.The optimal designs were verified by finite element simulation.The results show that optimal designs not only make the bus to meet the requirements of ECE Regulations No.66,but also reduce the mass of the bus body,while increasing the absorbed energy of the body structure,which effectively improve the rollover safety.