兼顾行人保护与低速碰撞的前保险杠吸能器设计

Design of Energy Absorber for Front Bumper with Concurrent Considerations of Pedestrian Protection and Low-Speed Collision

轿车前保险杠系统的设计需要同时满足行人碰撞与低速碰撞的要求。现代轿车设计中,通常通过在保险杠蒙皮和横梁之间增加吸能结构以满足此类要求。本文中首先提出了一种模块化的自适应轿车前保险杠X形吸能器,它可根据碰撞能量的大小,通过改变自身变形特征,分阶段地提升吸能能力。接着以某车型为基础设计了该吸能器,并基于GB/T 24550—2009行人保护法规和CMVSS215低速碰撞法规要求,利用有限元分析评估了其耐撞性能,并与常用泡沫吸能器进行了对比。结果表明:不同于传统泡沫吸能结构,该吸能器在行人碰撞和低速碰撞时会产生不同的变形模式,可以更好地兼顾两种不同要求。

The design of a car front bumper system needs to meet the requirements of both low speed collision and pedestrian impact,and modern car design often meets these requirements by adding energy absorbing structures in between bumper beam and fascia. In this paper,a kind of modular,adaptive and X-shaped energy-absorbing unit for car front bumper is proposed first,which can gradually increase energy absorbing ability by changing its deformation features based on the amount of impact energy. Then an energy-absorbing unit of this type is designed for a car make,and a finite element analysis is conducted to evaluate its crashworthiness performance based on pedestrian protection regulation GB / T 245550- 2009 and low-speed impact regulation CMVSS215,with comparison to the foam energy absorber of traditional bumper. The results show that being distinct from traditional foam absorber,the novel energy absorber exhibits different deformation modes in pedestrian impact and low-speed impact respectively,so better concurrently meeting two different requirements.