行人被面包车碰撞的运动学规律

为了丰富人车碰撞事故运动学理论，同时为面包车碰撞行人事故的分析鉴定提供理论支撑，对20～110 km·h^-1车辆碰撞速度下行人被面包车碰撞后的运动规律进行研究。利用多刚体建模系统PC-Crash软件构建面包车与行人碰撞仿真模型，并通过仿真获得多种碰撞条件下行人碰撞后的纵向/横向抛距、抛射高度、抛射角度、空中旋转圈数、躯干合成速度和头部合成加速度等运动学数据。结合国家车辆事故深度调查体系（NAIS）中14例具有可靠数据的事故样本进行比较验证。定义并提出了行人被面包车碰撞后的拱推型运动形态，以区别于长头车碰撞的卷绕型和平头车碰撞的推掷型。结果表明：拱推型碰撞中行人会在瞬间被加速到车辆碰撞速度的111%～127%；在高速（110 km·h^-1）碰撞中，头部合成加速度值超过3 000 m·s^-2，头部损伤指标（HIC）值超过7 500；行人空中旋转不超过3圈，被抛高度不超过4.0 m，抛射角度介于6°～11°；行人抛距与车辆碰撞速度之间的关系可以用幂函数模型进行描述；碰撞接触位置、车型外廓参数、行人行走速度和行人碰撞姿势对行人被抛运动形态有一定程度的影响，相对标准碰撞的影响程度一般在5%以内，最大不超过10%（边翻型除外）；行人头部损伤安全界限（HIC值为1 000）对应的车辆碰撞速度约为55 km·h^-1；边翻型碰撞中行人的运动形态与拱推型差别较大，横向抛距最大可达12.0 m。

Projection Kinematics of Pedestrian Impacted by Minivans

To enrich the kinematics theory of vehicle-pedestrian accidents, and provide support for technical analysis of minivan-pedestrian accidents, the post-impact kinematics of a pedestrian impacted by a minivan at an impact speed of 20-110 km·h^-1 were investigated. PC-Crash, a multi-body-based accident modeling system, was used to construct simulation models of collisions between minivans and pedestrians; in addition, simulation tests using various groups of impact parameters were also carried out to produce post-impact kinematics data on pedestrians including the longitudinal/lateral throw distance, projection height, launch angle, rotation number, velocity of the pedestrian torso, and head acceleration. Reliable data on fourteen real-world accidents from the national automobile accident investigation system (NAIS) database were selected to verify the simulation results. arch projection was originally proposed and defined to describe the projection of pedestrians impacted by minivans in order to distinguish from wrap projection of pedestrians impacted by long-fronted vehicles, and forward projection of pedestrians impacted by plane-nosed vehicles. The results show that an impacted pedestrian will instantly be accelerated at up to 111%-127% of the impact speed of the vehicle in arch projection. The value of the head acceleration will exceed 3 000 m·s^-2, and the value of the head injury criterion (HIC) will exceed 7 500 in high-speed impacts (110 km·h^-1). The number of rotations in air does not exceed 3.0, the projection height does not exceed 4.0 m, and the launch angle is between 6° and 11°. The relationship between the pedestrian throw distance and the vehicle impact speed can be described using a power formula. In addition, the contact position, profile parameter of the vehicle front, pedestrian's walking speed, and impact posture have a certain extent effect on the pedestrian's projection kinematics (except for fender vault), and the extent of such influences is generally less than 5% (the maximum not exceeding 10%) in a typical arch projection. The corresponding speed for the safety threshold of a head injury (the value of HIC is 1 000) is approximately 55 km·h^-1. The projection kinematics of fender vault has a large difference with arch projection, and the longest lateral throw distance of fender vault can reach up to 12.0 m.