Effects of pedestrian gait, vehicle-front geometry and impact velocity on kinematics of adult and child pedestrian head

The objective of the study is to investigate the effects of pedestrian gait, vehicle-front geometry and impact velocity on the dynamic responses of the head. The multi-body dynamic (MBD) models were used to simulate the head responses in vehicle to pedestrian collisions with different vehicle types in terms of head-impact point measured with Wrap Around Distance (WAD), head relative velocity and impact angle. Furthermore, the distribution of the head contact point on the vehicle fronts is analysed for a comparison of the contact point with the testing areas in the EEVC headform impactor test procedures. A simulation matrix is established using five vehicle types, two mathematical models of the pedestrians represented a 50th male adult and a 6-year-old child as well as seven pedestrian gaits based on typical postures in pedestrian accidents. In order to simulate a large range of impact conditions, four vehicle velocities (30 km/h, 40 km/h, 50 km/h and 60 km/h) are considered for each pedestrian position and vehicle type. The results indicated that the pedestrian gait and vehicle-impact velocity strongly influence head-impact condition. It is obvious that due to different vehicle-front geometry, the head-impact velocity, impact angle and head-impact point could be varied as well. This study provides suggestions for different head-impact conditions of subsystem test to the front part of different passenger vehicles.