基于行人落地碰撞的车辆前部结构参数分析

Analysis of Vehicle Front-end Structure Parameters Based on Pedestrian Landing Impacts

在行人-车辆碰撞事故中,行人头部损伤不仅源于行人与车辆的一次碰撞,而且还有与地面的二次碰撞.为了综合分析车辆前部结构参数对一、二次碰撞中行人运动学及头部损伤的影响,本文在MADYMO中对车辆前部结构(挡风玻璃角度(WA)、发动机罩角度(BA)、发动机罩长度(BL)、发动机罩前沿高度(BLEH)和离地间隙(GC))进行参数调整,构建一系列行人-车辆碰撞多体模型,并采用多元线性回归方法分析车辆参数对行人运动学和头部损伤的影响.结果表明,一、二次碰撞中,BLEH对行人头部HIC值(车)和行人旋转角度的影响均最为显著(p<0.01),BA对头部角加速度(车)的影响较BLEH更为显著,WA、BL和GC对行人运动学与损伤的影响均较小.较低的BLEH对一次碰撞中行人头部的保护更好,但BLEH过低易导致二次碰撞中行人头部首先与地面碰撞,这会增大头颈部的损伤风险.本文定量分析了车辆前部结构参数对行人一、二次碰撞的影响,研究结果可为车辆安全性设计提供理论参考.

In the pedestrian-vehicle collision accident, pedestrian may suffer head injury not only from the primary impact with the vehicle but also from the secondary impact with the ground. In order to comprehensively analyze the influence of vehicle front-end structure parameters on pedestrian kinematics and head injury in primary and secondary impacts,in this paper, a series of multi-body models of pedestrian-vehicle collisions were constructed by utilizing the MADYMO code, with adjusting parameters of windshield angle(WA),bonnet angle(BA),bonnet length (BL),bonnet leading edge height(BLEH) and ground clearance(GC). The influence significance of vehicle parameters on the pedestrian kinematics and injury was analyzed by using multiple linear regression analysis. The results indicate that BLEH is the most significant influence factor on head HIC value(car)(p<0.01) and pedestrian rotation angles in the primary and secondary impact,respectively.The influence of BA on the head angle acceleration (car) is more significant than that of BLEH. WA, BL and GC show a less influence on the kinematics and injuries of pedestrian. The lower BLEH provides better protection of the head in the primary collision, but it can easily lead to the head to collide with the ground firstly in the secondary impact, which increases the risk of head and neck injury. A quantitative analysis of the effect of vehicle front-end structure parameters on the primary and secondary impact was also conducted in the study, and the results can provide some reference for vehicle safety design.