This research focused on the technique of increasing the reaction force of the vehicle body in the interval between the onset of the crash (primary impact) and the moment the door strikes the occupant (secondary impact). A dynamic nonlinear Finite Element Method (FEM) simulation program (PAM CRASH) was used. An analysis was made of the body deformation behaviour of a four-door sedan in a side impact. A method was developed for preparing an analytical model having sufficient size to provide good correlation with the deformation behaviour of an actual vehicle in the interval between the primary and secondary impacts. The results obtained with the model were analyzed by examining time histories of the displacement of the displacement of body structural elements and strain distributions during the side impact phenomenon. The purpose of the analysis was to find how to reduce the impact velocity between the door and the occupant, which could be most effective in mitigating the thoracic trauma index (TTI) of the occupant. The results of the analysis clarified the deformation mechanism of the body structures. The results also indicated the respective contribution that various body reinforcements would make toward increasing the reaction force of the vehicle body.
Abstract