Validation of a Finite Element Human Model Throw Distance in Pedestrian Accident Scenarios

Increasing number of hit and run pedestrian accidents highlights the importance of accident reconstruction tools used in forensic investigations. The tools used nowadays are based on simplified assumption of particle to particle interactions (Searle’s model), or real life accidents (Happer’s model) which enable for prediction of collision velocity based on pedestrian throw distance evidence obtained at the scene of the accident. Unfortunately, vehicle impact speeds can only be estimated as a range of velocities, as the Searle’s model forms a velocity corridor which widens with the increase of measured throw distance giving a large number of predictions.
Development of computing architecture together with the advancement in computer human modelling opens the opportunity for bringing accident reconstruction studies to the next level and reducing the predicted velocities range. Nevertheless, to achieve this, the computer human models need to be reliable and robust. In this study, the Total Human Model for Safety (THUMS) was validated against analytical pedestrian throw distance models.
The validation studies were performed with THUMS 4.01 using 5 different stances, namely: two standing, two walking and one running pedestrian as well as 3 different vehicle impact velocities (20, 30 and 40). Analyses results were validated against Searle’s and Happer’s throw distance models.
THUMS kinematics agreed well with the current accident reconstruction tools in terms of model behaviour and predicted throw distance. The behaviour of the THUMS model is different for low and high velocity impacts showing good agreement to the field data in terms of body kinematics. In particular, low impact velocities cause wrap projection of the human body, while high impact velocities are