Finite-element modelling of restrained occupant partial ejection under rollover conditions

Rollover fatalities and serious injuries represent a large portion of the harm occurring in traffic crashes in the United States. Restrained occupants whose heads are reported partially ejected have a much worse outcome than those whose heads are not partially ejected. Prevention of partial ejection represents a significant objective in automotive design. In this study, two methods are investigated involving an empirical methodology and a finite-element-model methodology. A finite-element model of a production vehicle is utilised under rollover impact conditions in conjunction with a restrained occupant characterised by a Hybrid III dummy. The properties of the model are compared with human volunteer characteristics in the production vehicle. The restrained occupant model is then utilised under rollover impact conditions with the baseline production vehicle and modified versions of the roof structure. Comparison of the results associated with the empirical method and finite-element method is provided as are the results of the effects of the modified roof structure on partial ejection.