Research of the Relationship of Pedestrian Injury to Collision Speed, Car-type, Impact Location and Pedestrian Sizes Using Human FE Model (THUMS Version 4)

Injuries in car to pedestrian collisions are affected by various factors such as the vehicle body type, pedestrian body size and impact location as well as the collision speed. This study aimed to investigate the influence of such factors taking a Finite Element (FE) approach. A total of 72 collision cases were simulated using three different vehicle FE models (Sedan, SUV, Mini-Van), three different pedestrian FE models (AM50, AF05, AM95), assuming two different impact locations (center and the corner of the bumper) and at four different collision speeds (20, 30, 40 and 50 km/h). The impact kinematics and the responses of the pedestrian model were validated against those in the literature prior to the simulations. The relationship between the collision speed and the predicted occurrence of head and chest injuries was examined for each case, analyzing the impact kinematics of the pedestrian against the vehicle body and resultant loading to the head and the chest. Strain based indicators were used in the simulation model to estimate skeletal injury (bony fracture) and soft tissue (brain and internal organs) injury. The study results primarily showed that the injury risk became higher with the collision speed, but was also affected by the combination of the factors such as the pedestrian size and the impact location. The study also discussed the injury patterns and trends with respect to the factors examined. In all of the simulated conditions, the model did not predict any severe injury at a collision speed of 20 km/h.