【作者】 陈金华；

【导师】 黄向东；

【作者基本信息】 华南理工大学 ， 车辆工程， 2012， 博士

【摘要】 随着我国交叉型乘用车保有量的不断增加,其对行人碰撞的伤害也越来越多的引起学者和汽车厂家的重视,一直以来,国内外的学者和汽车厂商都将研究的重点放在传统轿车与行人的碰撞安全研究方面,而对交叉型乘用车行人保护的研究却相对较少,如何降低交叉型乘用车对行人碰撞的伤害,已经成为汽车安全领域一个急需研究和解决的问题,需对相关的设计理论和技术开展深入、细致的研究；本文基于某自主品牌交叉型乘用车行人保护性能的开发,通过理论分析、计算机仿真分析以及实车试验,为该自主品牌交叉型乘用车提供行人保护结构设计解决方案的同时,也为这一类车型的车辆探索出行人保护性能开发的方法和思路。本文建立了交叉型乘用车和一般轿车与行人碰撞的多刚体模型,分析得到了两种车辆与行人碰撞的动力学响应过程及差异,通过对主要人体伤害参数进行分析,识别出车辆前部结构尺寸及结构布置的不同是造成这种差异的主要原因,为交叉型乘用车有利于行人保护性能的前部结构设计提供了相应的理论依据。通过对交叉型乘用车同平台轿车进行行人保护性能摸底试验,分析并总结了同平台轿车在行人保护方面不足,提出了交叉型乘用车行人保护的设计方法,在头部碰撞设计方法中主要以头部溃缩空间指导碰撞区域的零部件布置和设计,并通过构建一恒定大小的理想方波减速度曲线拟合实际的碰撞减速度曲线推导了满足法规要求的头碰最小溃缩空间；在腿部碰撞设计方法中,提出了立体式腿型碰撞保护结构,并通过仿真分析验证了该结构的有效性。按照法规要求建立了子系统冲击器有限元模型并对有限元模型进行了验证分析,并在自主品牌交叉型乘用车开发中应用了本文提出的行人保护设计方法,通过建立整车与子系统冲击器的分析模型,对车辆开发各阶段的行人保护性能进行了分析,分析结果表明,应用本文提出的行人保护设计方案,并对方案中各零部件进行结构优化改进,目标车从不满足行人保护法规的要求到最终可以满足法规的要求,最终通过优化分析获得了更好的前部结构设计方案。根据最终的前部结构设计方案制造了交叉型乘用车的样车,并进行了行人保护头型和下腿型的碰撞试验,试验结果显示该车头型和腿型伤害值都没有超过法规的上限值,针对试验结果进行了仿真验证分析,验证结果显示试验结果与仿真分析结果具有很好的一致性,从而也证明了本文所建立的交叉型乘用车行人保护分析模型是稳定和可靠的,最后利用仿真分析结果并结合试验结果对该车进行行人保护性能的评价,结果表明该车完全可以满足行人保护法规GB/T24550-2009《汽车对行人的碰撞保护》中的相关要求。更多还原

【Abstract】 With continuously increasing of CrossOver Vehicle (COV) in China, the scholars and carmanufacturers paid more attention to the pedestrian injury caused by COVs. All the time thescholars and car manufacturers at home and abroad have mainly focused on the research ofpedestrian safety of traditional sedan, and the study of COV’s pedestrian protection wascomparatively less. How to reduce the pedestrian injury caused by COV has become anurgent problem in the field of automotive safety, which required in-depth and meticulousresearch on the design theory and technology. This paper is based on the performancedevelopment of pedestrian protection about the self-owned brand COV, by theoretical analysisand computer aided simulation analysis and the real vehicle test, not only providing structuredesign solutions of pedestrian protection for self-owned brand COV, but also exploring themethods and ideas of performance development of pedestrian protection for this type ofvehicles.By establishing the multi-rigid-body impact models of COV and traditional sedan withthe pedestrians, the differences of the pedestrian dynamic response with the two kinds ofvehicles were obtained. And it was identified that the distinct vehicle front structure size andlayout was the main reason for this difference. It provided a theoretical basis for thepedestrian protection performance design of COV’s front structure.The pedestrian protection test of a sedan which had the same platform with COV wascarried out and the disadvantages of the sedan in pedestrian protection was analyzed andsummarized, which brought out the design methods of COV. In head impact design method,head collapse space was used to guide the parts layout and design, and a constant idealsquare-wave deceleration curve was constructed to predict the minimum collapse space of thehead impact, which fitted the actual impact deceleration curve. In the leg impact designmethod, an integrated leg impact protection structure was proposed, and the validity of thestructure was verified through simulation analysis.The finite element models of the subsystem impactors were established and verifiedaccording to the regulations and the pedestrian protection design methods proposed in thispaper were applied to the development of self-owned brand COV. The analysis models of vehicle-subsystem impactor were established, and the pedestrian protection performance ofCOV was analyzed in the different development stage, of which results show that by theapplication of proposed pedestrian protection design and optimization of the structure, thetarget vehicle finally meet the requirements of the regulations and get a better front structuredesign through optimization analysis.The COV prototype was made according to the final front structure design and thepedestrian protection test was carried out. The test results showed that all the injury values ofhead and leg were under upper limit of the regulations. The test and simulation verificationresults showed that the test results were in good correlation with simulation results, whichalso proved that the pedestrian protection analysis of the COV model was stable and reliable.Finally, the simulation and test results of COV’s pedestrian protection performance revealedthe target COV could meet the requirements of GB/T24550-2009(The protection of motorvehicle for pedestrians in the event of a collision).更多还原