Vehicle crashworthiness in frontal collisions is often evaluated using a procedure that simulates a full frontal crash between two vehicles. In the real world, however, many of the accidents regarded as frontal collisions are oblique offset impacts. Such impacts may differ from full frontal collisions in terms of vehicle body deformation and occupant behavior, owing to differences in the position and direction of the input crash energy. The distribution of occupant injuries in real-world accidents tends to vary depending on the impact angle. Accordingly, researching occupant protection measures based on a good understanding oblique offset impacts is a useful approach to help enhance vehicle safety performance further. In this work, vehicle body deformation and dummy behavior were analyzed in frontal oblique offset impacts, involving car-to-car crashes of ordinary medium-size passenger vehicles, and in FEM simulations. A fundamental research study was then made of the results to identify the characteristics of frontal oblique offset impacts. The collision test results revealed that cabin deformation tended to increase when crash energy was applied at an oblique angle. It was observed that the struck vehicle also moved sideways, causing the force of inertia to act on the dummy. As a result, the dummy's upper torso translated sideways and ankle inversion/eversion occurred. In the FEM simulations, it was seen that the front side member of the struck vehicle sustained less axial deformation and that the engine compartment absorbed less energy than in the full frontal collision, resulting in the cabin structure needing to absorb larger proportions of the crash energy.

FEM simulations showed that providing a subframe to connect the front side members and the floor panel increases the energy-absorbing capacity of the engine compartment. Additionally, MADYMO (Mathematical Dynamic Model) simulations showed that side-impact airbags on the struck side reduce the lateral translation of the near side dummy's upper torso. These simulations also showed that applying a control load that acts on the thighs and lower legs in the lateral direction reduces ankle inversion/eversion.