行人头部撞击汽车发动机罩盖的多波峰特征与结构设计

摘要

The impact response of pedestrian headform was analyzed to understand the influence of vehicle hood design in assessment tests of pedestrian protection performance.The impact pulse (acceleration-time history) of the pedestrian headform generally composed of multiple peaks.Each phase was dominated by location specific factors,including active mass,structural stiffness,boundary constraints and deformation space under vehicle hood.Vehicle hood design shall take into account of these dominating factors under given design constraints to minimize value of the head injury criterion.As an application example,the study presented a sandwich hood structure design on a production vehicle model.The results show that the sandwich hood structure can prove capable of improving the headform protection performance compared to conventional hood.%为了解汽车发动机罩盖的结构设计对行人头部冲击响应的影响机理,提出了一种结构设计.根据行人头部冲击器与发动机罩盖碰撞加速度波形的多个波峰的特征,划分为不同阶段;分析了罩盖的碰撞变形过程和吸能机理,各阶段分别受罩盖随动质量、结构刚度、边界支撑及下方变形空间等因素的主导;对各主导因素进行补偿,以实现最优波形的罩盖结构设计方法.以某量产车型作为工程应用实例,给出了具有夹层板结构的发动机罩盖设计方案.结果表明:该设计能够改善行人头部碰撞保护性能,为发动机罩盖设计提供参考.