汽车后座椅骨架行李冲击分析与结构优化

Luggage Impact and Structure Optimization for Rear Seat Frame of Automobile

为减少交通事故中行李块冲击引起的后排乘员伤亡,设计安全可靠的后排座椅骨架结构,使之通过ECE R17法规标准是当前后排座椅设计的基本要求。以某汽车后排座椅骨架为研究对象,建立其精确的CAD模型,按照ECE R17法规要求,运用非线性有限元方法对其进行仿真研究。计算结果表明座椅骨架及固定安装支架存在两个问题:(1)该分体式座椅骨架吸能和抗变形能力严重不足;(2)座椅骨架固定点连接支架不够牢固,在冲击工况下易脱落。根据试验及仿真结果,提出改变该分体式座椅骨架为整体式座椅骨架,提高座椅骨架的整体刚度,增强抗变形能力;中部安装支架采用整体式结构,其余安装支架结构不变,厚度增加0.5 mm。通过对改进方案进行分析验证,表明改进后方案抗变形能力优于分体式结构,满足法规要求。

To reduce the rear occupant casualities in traffic accidents caused by the impact of luggage block, it is necessary to design a safe and reliable rear seat frame structure and meet regulations and standards by ECE R17. Taking a car rear seat frame as study object, its precise CAD model was established. According to ECE R17 regulations, the nonlinear finite element method was used to simulate and study the object. The finite elements results show that there are two problems： firstly, energy absorption and resistance to deformation of the split seat frame is serious short; secondly, fixed-point connection bracket of the seat frame is not strong enough and easy to fall off in shock conditions. In order tO improve the overall stiffness and resistance to deformation of the seat frame, an overall split seat frame instead of the split seat frame was proposecl. Center support bracket was the overall structure and the rest mounting bracket structure was unchanged, but the thickness was all increased 0. 5 mm. Through the analysis of the improvement program, the results demonstrate that deformation resistance of improved scheme is superior to the split structure and meet regulation requirements.