Research On The Comprehensive Pedestrian Leg Protection And Low Speed Impact Performance Of Bumper

Bumper is the necessary safety part of automobile. It is designed to protect thewing, cooling system, hood, radiator as well as easy-damaged parts such as headlampsin low speed collisions. Therefore, an adequately stiff bumper is typically needed.However, the car bumper was the first to hit pedestrian lower extremity in mostcar-to-pedestrian accidents. The injury of pedestrian lower extremity would beaggravated in this kind accident if the bumper has a significant stiffness. With theregulations of low speed impact test and pedestrian protection, experimental methodand finite element method were used to study the combination performance ofautomobile bumper in this article.A large number of academic literatures about bumper research methods andsituation on low speed impact and pedestrian protection were reviewed andsummarized. Analysis of relative regulations was conducted, and some veryinfluential low speed test and pedestrian protection regulations were discussed indetail. The above work provided references for analysis of low speed impact andpedestrian protection performance of bumper and development of low speed impacttest device. Finite element simulation research on a production sedan’s bumper and aSUV’s bumper was conducted based on ECE R42(low speed impact test regulation)and Regulation (EC) No78/2009(pedestrian protection regulation), and the resultshowed that both bumpers had low performance on pedestrian protection. Then, thereasons were analyzed and the methods for bumper design with consideration ofpedestrian protection and low speed impact were proposed. Based on this, the sedanbumper beam was redesigned, and optimization for pedestrian protection wasconducted through central composite design method and adaptive response surfacemethod. Compared with the original beam, the performance of the new beam oncrashworthiness and pedestrian protection was enhanced effectively. At last, in theexisting experimental conditions, bumper impact tests were conducted and thenecessity of development of low speed impact test device was proposed. Then the testdevice was designed and the CAD and finite element models were created. Meanwhile,the strength and stiffness of test device was verified by finite element simulation.