轿车B柱耐撞性与轻量化优化设计研究

Study on Optimal Design of B-pillar for Crashworthiness and Light-weighting

为了在提高轿车侧面碰撞中B柱耐撞性能的同时减小B柱的质量以实现车身轻量化,对某车侧面碰撞的安全性能进行了有限元分析。针对在侧面碰撞中B柱腰线处侵入量和侵入速度过大、B柱结构中加强板数目较多及超重等问题,采用拼焊板结构对B柱外板进行了改进设计。在兼顾耐撞性与轻量化的前提下,使用正交试验设计和多目标遗传算法对拼焊焊缝的位置以及各部分的厚度进行优化。通过优化设计,改善了B柱在侧面碰撞中的变形模式。B柱最大侵入量减小了10%,腰线处侵入量和侵入速度分别减小了18%和12%,质量减小了18%。结果表明,在B柱上使用拼焊板结构并进行优化设计能够有效地平衡耐撞性和轻量化的要求。

In order to enhance crashworthiness of B-pillar in side impact and reduce its mass at the same time to achieve light-weighting,the safety performance of a car was analyzed according to the design parameters of the B-pillar in side impact firstly.It is identified that the intrusion and intrusion velocity at the middle of the B-pillar are too large and the mass of the B-pillar structure is rather high due to extra reinforcements.An improved design of the B-pillar was implemented using the tailor-welded blank structure.Furthermore the location of weld and thickness of this structure were optimized by using design of experimental method and multi-objective genetic algorithm,considering crashworthiness and light-weighting.A desired deformation mode of B-pillar was finally obtained.Its maximum intrusion is reduced by 10%.The intrusion and intrusion velocity at the middle of B-pillar are reduced by 18% and 12% respectively.The mass is reduced by 18%.The results indicate that optimal design of B-pillar structure with tailor-welded blank can effectively balance the requirements of crashworthiness and light-weighting.