毕业论文：汽车前保险杠结构及安全性能分析.doc

汽车前保险杠结构及安全性能分析
A STUDY ON THE STUCTURE AND THE SAFETY PERFORMANCE OF THE VEHICLE FRONT BUMPER
专业:机械设计制造及其自动化(汽车工程)
摘要
前保险杠系统作为安全防护装置是现代汽车结构的重要组成部分。它要在“低速碰撞”时“硬”些,防止汽车发生大的变形以致冲击侵入驾驶舱伤害乘员的安全。同时,当汽车与行人相碰撞时要“软”些,以避免或减少汽车对行人产生伤害。可见,它的结构对于汽车的安全性能起着至关重要的作用,它能有效地减轻汽车损坏以及人员伤亡的情况。因此,随着人们安全意识的不断提高,前保险杠系统成为了国内外汽车被动安全领域的重点研究对象。
过去对于乘员的保护已经做了很多研究,所以本论文主要侧重于前保险杠结构对行人的保护研究。根据我国现行的行人安全保护法规,本论文采用计算机模拟仿真技术,针对行人下肢的防护,对汽车前保险杠的结构及其安全性能展开研究。论文把人体下肢损伤机理作为理论依据,利用CATIA软件建立两款汽车前保险杠系统的简化几何模型,应用HYPERMESH软件划分网格,引进了本校损伤生物力学与车辆安全工程中心的人体下肢仿真模型;利用PAM-CRASH软件模拟行人下肢-汽车前保险杠碰撞试验并进行相应的求解计算。根据行人保护法规规定行人下肢损伤的三项评价指标(胫骨加速度、膝关节弯曲角度和膝关节剪切位移),对两款汽车前保险杠模型的碰撞试验结果进行分析比较。分析结果表明,车型1的前保险杠系统能够有效保护行人的安全;然而车型2的前保险杠系统不能为行人提供有效的防护,本文对其提出了改进的措施。
本研究是对我国前保险杠安全性能课题的有益探索,致力于通过整合建模到模拟试验的整个过程,总结出有效的、有利于行人保护的前保险杠安全性设计的计算机仿真试验方法。
关键词:碰撞安全; 行人下肢; 前保险杠系统; 冲击损伤生物力学
ABSTRACT
As a safety devise, Front Bumper System is an important part of a modern automobile. When a low-speed collision occurs, the Front Bumper System should be “stiff” enough to avoid large deformation of the car and protect the passengers from the impact of the collision. Meanwhile, when a pedestrian is hit by the front part of a car, the Front Bumper System should be “soft” enough in case that it will do harm to the pedestrian. Obviously, the structure of the Front Bumper System plays a very important role in the safety performance of an automobile. Therefore, with people’s increasing awareness of safety ,the Front Bumper System has already e a key problem in passive vehicle safety area at home and abroad.
Large numbers of studies on the protection for passengers have been done previously, for which this paper mainly focuses on the one for pedestrians. According to the lately pedestrian laws and regulations in China, this paper mainly studies on the structure and the safety performance of the automobile puter simulation for the protection of the lower limbs of the pedestrians. This paper takes the injury mechanism of lower limb as theory; builds the geo