A Study On Pedestrian Head Injury Prevention

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.