多胞体汽车后防撞吸能器耗能机制研究与结构优化设计

Energy dissipation mechanism study and structural optimization design of car rear anti-collision multi-cellular energy absorber

为有效提升后防撞系统耐撞性能以满足碰撞冲击载荷作用下的车辆被动安全需求,研发了6种正多边形镶嵌的多胞体薄壁吸能器。基于简化超折叠单元理论分析了截面参数和肋板连接方式对薄壁吸能器的能量耗散途径与影响机制;采用ABAQUS数值仿真探究了各种吸能器吸能特性,同时揭示了正八边形截面、肋板对边连接的薄壁吸能器吸能特性优异;依托拉丁超立方试验方法和基于Kriging代理模型的NSGA-II遗传算法进行多目标优化,确定了吸能器内薄壁管截面尺寸、管壁和肋板厚度分别为18.073 mm、1.669 mm、1.924 mm。结果分析表明,参数优化后的正八边形多胞体吸能器压溃吸能过程平稳可靠,能够为后防撞系统吸能器的结构设计提供参考。

Here,to effectively improve crashworthiness of car rear anti-collision system and meet the passive safety requirements of vehicles under collision impact loads,6 types of multi-cell thin-walled energy absorbers embedded with regular polygons were developed.Based on the theory of simplified super folding elements,influencing ways and mechanisms of cross-sectional parameters and ribbed plate connection modes on energy dissipation of thin-walled energy absorbers were analyzed.ABAQUS finite element numerical simulation was used to explore energy absorption characteristics of various energy absorbers,and reveal excellent energy absorption characteristics of thin-walled energy absorber with regular octagonal cross-section and rib plate opposite edge connection.With Latin hypercube test method and NSGA-II genetic algorithm based on Kriging surrogate model,multi-objective optimization was performed to determine cross-sectional size,wall and rib plate thicknesses of thin-walled tube inside energy absorber being 18.073 mm,1.669 mm and 1.924 mm,respectively.The result analysis showed that the crushing and energy absorption process of the octagonal multi-cell energy absorber after parametric optimization is stable and reliable,this energy absorber can provide a reference for structural design of energy absorbers in car rear anti-collision system.