【作者】 莫富灏；

【导师】 杨济匡；

【作者基本信息】 湖南大学 ， 车辆工程， 2009， 硕士

【摘要】 易受伤害道路交通使用群体的损伤防护研究已逐步受到世界各国的关注。在中国,行人及骑自行车人是伤亡率极高的两个易受伤道路交通使用群体。本文主要在于分析不同碰撞条件与行人头部动力学响应的联系,并同时对比了行人与骑自行车人头部动力学响应的异同,进一步分析了汽车前部结构中发动机罩系统对行人头部损伤的影响,并讨论相应的损伤防护措施。首先,本文利用深入的事故调查研究中筛选的数据,重建了多起轿车-行人事故、轿车-骑自行车人,从而验证了仿真模型的有效性。基于验证模型建立参数分析模型,设定不同的汽车车速、行人/骑自行车人速度、碰撞位置及百分位人体模型,从而分析了这些参数对两者头部动力学响应的影响。研究表明,车辆速度、碰撞位置及百分位人体模型对行人及骑自行车人头部动力学响应较大。之后,本文就发动机罩内外板厚度对头部损伤的影响进行了回归分析,并进一步讨论了发动机罩铰链的改进措施。研究结果表明,内板厚度参数对头部HIC值和侵入量的影响明显大于外板;通过线性回归的方法可得到HIC值、头部碰撞侵入量与发动机罩内外板厚度间的关系,从而为发动机内外板设计提供参考依据;合理的铰链结构改进可以有效地提高发动机罩系统的吸能能力,特别是降低铰链区域头部碰撞的HIC值。最后,研究分析了主动式发动机罩的设计原理,提出了相应的机械设计及电子控制基本原理。并在此基础上,建立了主动式发动机罩弹出高度多刚体分析模型及头部碰撞有限元仿真模型,分析了主动式发罩对行人头部动力学响应及损伤的影响。研究表明,弹出高度的增加将减少行人头部与发动机罩碰撞的角度,从而使行人的头部动力学响应值朝有利于降低行人头部损伤风险的方向变化;主动式发动机罩具有明显的吸能缓冲效果,可有效地降低行人头部损伤的风险。本文为轿车-行人碰碰撞中颅脑损伤防护技术的开发,提供了一套有效的分析思路及方法,仿真分析结果可作为车辆行人安全设计的参考依据。更多还原

【Abstract】 Injury protection research on vulnerable road users has been arising more and more attention step by step. Pedestrian and bicyclist are two vulnerable road users with the high injury rate in road vehicle traffic accident in China.The main aim of this thesis is to analyze relationship between different crash conditions and head kinematics responses, and compare the pedestrian and bicyclist head dynamics. Morover, this research analyze the influences of hood system on head-brain injury in car-pedestrian crash, and discuss relative injury protection measures on pedestrian safety.First, many car-pedestrian and car-bicyclist accident reconstructions were carried out using selected accident data from an in-depth study for validating the simulation model. Based on the validated model, this paper set up the parameter analysis model as well as adopting different vehicle velocity, pedestrian or bicyclist velocity, crash position and percent Human-Body 3D Mathematical Model. Then, the influences of these parameters on pedestrian and bicyclist head dynamic responses were analyzed carefully. As the research results shown, vehicle velocity, pedestrian velocity, crash position and percent Human-Body 3D Mathematical Model can affect head dynamic responses largely.Then, the current thesis analyzed the influence of thicknesses of outer and inner hood on head injury through regression analysis, moreover, discussed some improving measures on hood joint. The simulation results show that inner hood thickness can affect HIC and intruding value of pedestrian head more obviously compared with that of outer hood. Correlation of HIC and intruding value to thicknesses of outer and inner hood could be got through regression analysis. The results can provide references for vehicle hood design. In addition, reasonable improvement on hood joint can improve absorbing energy ability of hood system availably with decreasing HIC of head impact around joint area largely.Finally, this research analyzed basic design theory of active hood and present corresponding mechanical design and electronic control theory. In that case, this paper analyzed the influences of active hood on head injury and head dynamic responses of pedestrian. As the research results shown, active hood can decrease the crash angle between head and hood, and make the value of head dynamic responses change to the direction of decreasing head injury risk. And it also decline risk of head injury largely.This study provided some effective measures for pedestrian safety protection, which can be used as vehicle design reference.更多还原