Pedestrian response with different initial positions during impact with a mid-sized sedan

Real-world pedestrian impacts occur with highly-variable or unknown initial conditions of the pedestrian. However, experimental pedestrian tests and computational pedestrian impact simulations mainly focus on the response of the subject using specific initial conditions. The objective of this study is to investigate computationally the influence of posture and impact direction angle on pedestrian response during an impact. The 50 male THUMS pedestrian model was integrated with a mid-sized sedan finite element model initially travelling at 40 km/h. The influence of the pedestrian position during impact was investigated by varying 9 orientations (relative to the vehicle) and 3 standing/gait postures, for a total of 27 impact configurations simulated. Pedestrian kinematics and injury were assessed and compared across all simulations. Substantial variations were observed on the pedestrian torso rotation (-68.9°~57.6°), and head impact conditions (head impact time 111~139 ms, and head impact velocity 10.7~15.3 m/s). The head impact velocity was found to correlate with the impact direction angle, where facing towards or away from the vehicle would result in greater head impact velocity than when struck in a purely-lateral impact.