基于新FMVSS301的汽车车体小重叠率追尾碰撞优化设计

Optimization Design of Car Body Rear-End Collision with Small Overlap Ratio Based on New FMVSS301

汽车在高速追尾碰撞过程中极易对车内乘员造成伤害,容易导致油箱破裂致使燃油泄漏造成更严重的伤害。为了评价汽车在追尾碰撞事故中的耐撞性,根据北美联邦机动车安全法规新FMVSS301要求,应用LS-DYNA与HyperWorks软件,建立了速度差为80km/h、重叠率为30%的车-车追尾有限元模型,通过选取碰撞过程车体尾部节点、中部节点和前部节点处3点验证了真个模型的有效性,进而仿真分析得出碰撞过程中能量的转移路径,找出了主要承力部件,针对性地对汽车纵梁、保险杠和地板后部进行材料匹配的优化设计,最终得出:合成材料GMT(玻璃纤维增强型热塑性塑料)可以有效地降低碰撞导致的车门、底板后部等主要部件的侵入量,进而为碰撞试验提供思路与依据。

In the process of high-speed rear-end collision,it is very easy to cause injuries to the passengers inside the car,and it can also easily lead to rupture of the fuel tank and cause more serious damage due to the fuel leakage.To evaluate the vehicle crashworthiness in tracing collision accidents,according to the request of new FMVSS301 North American Federal Motor Vehicle Safety Regulations,the finite element model of car-car rear-end with speed difference of 80km/h and overlapping rate of 30%is established by using the LS-DYNA and HyperWorks software.The effectiveness of the whole model is verified by selecting three points at the tail node,the middle node and the front node of the car body during the collision process;then the energy transfer path in collision process is obtained through the simulation analysis,and the main bearing parts are found out;thus the material matching optimization design for the longitudinal beam,bumper and rear of floor is conducted.Finally,it isconcluded that the GMT(glass fiber reinforced thermoplastic)can effectively reduce the intrusion of main components such as doors and the back of bottom plate caused by collision,thus providing ideas and basis for the collision tests.