Thorsten Adolph, Julian Ott, Burkhard Eickhoff, Heiko Johannsen

• Frontal impact is still the most relevant impact direction in terms of injury causation amongst car occupants. Especially for car-to-car frontal impacts the mass ratio between the involved vehicles has a significant impact on the injury risk (the heavier the opponent car the higher the injury risk). In order to address this issue frontal Mobile Deformable Barrier test procedures have been developed world-wide (for example the MPDB procedure that was fully described during the FIMCAR Project). The objective of this study was to investigate how vehicles of different weight classes perform in a mobile barrier test procedure compared to a fixed barrier test procedure (the full width rigid and offset deformable barrier test). Beyond that, the influence of vehicle mass and vehicle deformation on injuries was evaluated based on real world accident data. Five vehicle types were selected and tested in a fixed offset test procedure (ODB), a full width rigid barrier test procedure (FWRB) and a mobile offset test procedure (MPDB). For the accident analyses data from the German In-Depth Accident Study (GIDAS) was evaluated with a focus on MAIS 2+ injured belted front row car (UN-R 94 compliant cars) occupants in frontal impact accidents. Test data indicates higher dummy loadings, in particular for the head acceleration and chest acceleration, in the MPDB test for the vehicles with a mass lighter than the trolley (1,500 kg) compared to the FWRB test. The trend of increased vehicle stiffness (especially illustrated by tests with the MPDB and small cars) shows the need of a further improvement of passive restraint systems to reduce the occupant loading and with it the injury risk. The analyzed GIDAS data confirm the higher injury risk for occupants in cars with an accident weight of less than 1,500 kg compared to those with a crash weight above 1,500 kg in car-to-car and car-to-object or car-to-HGV, respectively. Furthermore the injury risk increases with decreasing mass ratio (i.e., the opponent car is heavier) in car-to-car accidents. Independent from the higher injury risk, the risk for passenger compartment intrusion in frontal impact appears not to be independent on the crash weight of the car.