Mechanics Analysis Of Head-Ground Collision Based On Vehicle-Pedestrian Crash Accident Reconstruction

Because of the rapid increase of car possession quantity, the uneven makings of a driver, and the high proportion of mixed traffic mode which has existed in our country for a long time, at present, within the road accidents in our country, the quantity and the proportion of vehicle-pedestrian crash accidents as well as pedestrian casualty are at a fairly high level at all time. And within the statistic of pedestrian injury area distributions, head is the most frequent injured area, and head impact injury is the common injury and one of the mainly deadly causes during traffic accidents. Therefore, it is very significant to launch the analysis of vehicle-pedestrian crash accidents and the mechanics analysis of head collision injury in our country.This study aims at improving the security of pedestrian in crash accidents. Based on investigation and analysis of typical vehicle-pedestrian crash accidents, vehicle-pedestrian crash models are built by MADYMO, which is a Multi-body dynamics simulating software. Then the accident simulation reconstructions are carried on by MADYMO too. By comparing with the relevant investigation reports of accidents,it is revealed that results of accident reconstructions by and large accord with the facts of accidents. After analyzing the results of accident reconstructions, conclusion is made that during the vehicle-pedestrian crash accidents, different crash effects would be brought to pedestrian's body, following with varieties of factors such as vehicle types, crash speeds, statures and body forms of pedestrian, the movements and the poses of pedestrian before and after crash, consequently, different movements and injuries will be induced.On the bases of crash accident simulation reconstructions, forehead-ground, temporal-ground, and occipital-ground collision finite element models are built respectively. To study the mechanics responses of pedestrian brain injury which happens during head-ground collision, collision models are analyzed by explicit finite element analysis software—LS-DYNA. According to the results of simulations, the effects of collision areas and velocities on head injury are analyzed. Conclusions are made that during head-ground collisions, at the collision velocity of 15 km/h, the probabilities of skull fracture and serious brain injury are great in all of the three cases; when the collision velocity up to 20 km/h, fatal injuries may occur in head. Head model using in crash models is improved from the head FE model, which is produced by TNO company and supplied by university of Birmingham in Britain.This study is a useful exploration of research on pedestrian security in our country. The methods and conclusions of this study are provided with important significance on providing reference for vehicle-pedestrian crash accident reconstruction, research on pedestrian injury especially head injury, and legislation of pedestrian protection.