面向行人安全的保险杠结构改进优化

针对行人下肢的碰撞保护,建立了某车型的有限元碰撞模型并进行了试验验证。为改善行人保护性能,提出了添加吸能泡沫及副保险杠的改进方案。以吸能泡沫厚度、主副保险杠垂向距离、副保险杠壁厚这3个结构参数为设计变量,构造了优化的拉丁超立方试验,结合最小二乘法建立胫骨加速度、膝关节弯曲角度及剪切位移3个伤害指标的响应面模型,运用多目标遗传算法进行优化求解。对比结果表明,优化后的结构有效地降低了行人腿部受到的伤害,满足了安全法规要求。

Bumper structure optimization for pedestrian leg protection

A finite element collision model was established to simulate the collision between pedestrian''s lower leg and a car, and it was verified through experiment. In order to improve the performance of pedestrian protection, auxiliary bumper and energy-absorption foam were added in the car. With taking the thickness of energy-absorption foam, the vertical distance between bumper and auxiliary bumper and the thickness of auxiliary bumper as design variables, an optimized Latin hypercube experiment was conducted. The response surface model (RSM) for the injury index of leg was fit with experimental data by using the least square method, and the optimal design parameter of bumper was solved by multi objective genetic algorithm (MOGA). The results indicate that the injury of the pedestrian leg is reduced effectively by using the optimal structure, which meets the safety requirements.