截面形状对汽车前纵梁碰撞性能的影响分析

摘要

In the frontal impact,the front longitudinal rail is the main energy-absorbing component,and it determines the crashworthiness and safety of vehicle in a large part.To study the crashworthiness of front longitudinal rail,the finite element models of front longitudinal rail with five different sections (U-shape,rectangular,square,hexagon,and circular) made of two materials (steel and aluminum) colliding with the rigid wall are built.Based on piecewise linear plastic material constitutive model and explicit dynamic algorithm,the dynamic simulations for collision between front longitudinal rail and rigid wall are made and the results of the front longitudinal rail deformation,energy variation and the impact force curve are obtained.The influences of section types and material on the crashworthiness of front longitudinal rail are analyzed.The results will provide theoretical basis for structural optimization design of front longitudinal rail.%前纵梁是汽车正碰主要吸能部件,在很大程度上决定了汽车的碰撞性能与安全性.为研究汽车前纵梁的碰撞性能,建立了两种材料(钢和铝)及五种不同截面形式(U形、长方形、正方形、六边形和圆形)的前纵梁与刚性墙碰撞有限元模型.采用分段线性塑性材料本构模型和显式动力学算法对其碰撞过程进行动态仿真,获得了前纵梁的变形情况、能量变化情况和碰撞力曲线,分析了不同截面形式及材料类型对前纵梁碰撞性能的影响,为前纵梁的结构设计与优化提供了一定的理论依据.