Investigating Pedestrian Kinematics with the Polar-II Finite Element Model 2007-01-0756
Previous full-scale pedestrian impact experiments using post-mortem human surrogates (PMHS) and sled-mounted vehicle bucks have shown that vehicle shape relative to pedestrian anthropometry may influence pedestrian kinematics and injury mechanisms. While a parametric study examining these factors could elucidate the complex relationships that govern pedestrian kinematics, it would be impractical with PMHS tests due to the relative expense involved in performing numerous experiments on subjects with varying anthropometry. Finite element (FE) modeling represents a more feasible approach since numerous experiments can be conducted with a fraction of the expense. However, there have been no studies to date depicting kinematic validation of a human pedestrian FE model in full-scale collisions using different vehicle and pedestrian geometries. Therefore, this study used an FE model of the Polar-II pedestrian dummy that was previously validated against full-scale test data. In order to evaluate the influence of shifting body contact points with respect to vehicle geometry on impact kinematics, multiple simulations were performed by moving the pedestrian vertically with respect to the vehicle reference frame. Next, to evaluate the contribution of the mass distribution with respect to vehicle geometry, simulations were performed where the center of gravity of the dummy was shifted around the baseline location. The results of this study suggest a nonlinear sensitivity of response to changes in the body contact points with respect to vehicle structures and a linear variation of upper body trajectories when the dummy center of gravity height was adjusted.