Li Guibing, Yang Jikuang, Simms Ciaran
School of Automobile and Mechanical Engineering, Changsha University of Science and Technology, Changsha, 410114, China; Centre for Bioengineering, Department of Mechanical and Manufacturing Engineering, Trinity College Dublin, Ireland.
Research Center of Vehicle and Traffic Safety (VTS), State Key Lab of Advanced Design and Manufacturing for Vehicle Body, Hunan University, China; Vehicle Safety Division, Department of Applied Mechanics, Chalmers University of Technology, Sweden.
Accid Anal Prev. 2017 Mar;100:97-110. doi: 10.1016/j.aap.2017.01.006. Epub 2017 Jan 25.
Vehicle front shape has a significant influence on pedestrian injuries and the optimal design for overall pedestrian protection remains an elusive goal, especially considering the variability of vehicle-to-pedestrian accident scenarios. Therefore this study aims to develop and evaluate an efficient framework for vehicle front shape optimization for pedestrian protection accounting for the broad range of real world impact scenarios and their distributions in recent accident data. Firstly, a framework for vehicle front shape optimization for pedestrian protection was developed based on coupling of multi-body simulations and a genetic algorithm. This framework was then applied for optimizing passenger car front shape for pedestrian protection, and its predictions were evaluated using accident data and kinematic analyses. The results indicate that the optimization shows a good convergence and predictions of the optimization framework are corroborated when compared to the available accident data, and the optimization framework can distinguish 'good' and 'poor' vehicle front shapes for pedestrian safety. Thus, it is feasible and reliable to use the optimization framework for vehicle front shape optimization for reducing overall pedestrian injury risk. The results also show the importance of considering the broad range of impact scenarios in vehicle front shape optimization. A safe passenger car for overall pedestrian protection should have a wide and flat bumper (covering pedestrians' legs from the lower leg up to the shaft of the upper leg with generally even contacts), a bonnet leading edge height around 750mm, a short bonnet (<800mm) with a shallow or steep angle (either >17° or <12°) and a shallow windscreen (≤30°). Sensitivity studies based on simulations at the population level indicate that the demands for a safe passenger car front shape for head and leg protection are generally consistent, but partially conflict with pelvis protection. In particular, both head and leg injury risk increase with increasing bumper lower height and depth, and decrease with increasing bonnet leading edge height, while pelvis injury risk increases with increasing bonnet leading edge height. However, the effects of bonnet leading edge height and windscreen design on head injury risk are complex and require further analysis.
车辆前部形状对行人受伤情况有重大影响，而实现全面行人保护的最佳设计仍是一个难以实现的目标，尤其是考虑到车辆与行人事故场景的多样性。因此，本研究旨在开发并评估一种有效的框架，用于针对行人保护的车辆前部形状优化，该框架考虑了现实世界中广泛的碰撞场景及其在近期事故数据中的分布情况。首先，基于多体模拟与遗传算法的耦合，开发了一种针对行人保护的车辆前部形状优化框架。然后将该框架应用于优化乘用车前部形状以实现行人保护，并利用事故数据和运动学分析对其预测结果进行评估。结果表明，该优化显示出良好的收敛性，与现有事故数据相比，优化框架的预测得到了证实，并且该优化框架能够区分对行人安全而言“好”与“差”的车辆前部形状。因此，使用该优化框架进行车辆前部形状优化以降低整体行人受伤风险是可行且可靠的。结果还表明了在车辆前部形状优化中考虑广泛碰撞场景的重要性。一辆对行人全面保护的安全乘用车应具有宽阔且平坦的保险杠（从小腿到大腿根部覆盖行人腿部，接触通常较为均匀）、发动机罩前缘高度约为750毫米、短发动机罩（<800毫米）且角度较浅或较陡（大于17°或小于12°）以及浅挡风玻璃（≤30°）。基于群体层面模拟的敏感性研究表明，对于安全乘用车前部形状在头部和腿部保护方面的要求总体上是一致的，但与骨盆保护存在部分冲突。特别是，头部和腿部受伤风险均随着保险杠下部高度和深度的增加而增加，随着发动机罩前缘高度的增加而降低，而骨盆受伤风险则随着发动机罩前缘高度的增加而增加。然而，发动机罩前缘高度和挡风玻璃设计对头部受伤风险的影响较为复杂，需要进一步分析。
