Car Compatibility in Frontal Crashes: New Methods to Determine the Influence of Mass, Structure, Stiffness, and Geometry, and their Interactions on Injuries

Vehicle-to-vehicle crash compatibility affects vehicle compartment acceleration and intrusion, which are the two main causes of car occupant injuries. A better understanding of compatibility effects is needed to establish safety priorities and improve occupant and partner protection. For this purpose, three new methods were developed to study individual compatibility effects on occupant and partner protection of car structure, mass, and local stiffness, respectively. Additionally, an integrated vehicle-occupant mathematical model was developed and used to estimate the relative significance of and interactions between vehicle mass, front structure and geometry. An epidemiology study was carried out with Volvo crash material to determine the individual effect of overlap amount on injury risk in frontal offset crashes. Age, gender and impact severity biased the injury effects of overlap amount. These biases were minimized using new techniques to sort the crash data, which resulted in a data-set of 654 cases. In crashes with an equivalent barrier speed > 32 km/h, most injured (40-43 %) were caused by frontal crashes with 1/3 to 2/3 overlap, whereas the highest injury risk was found fo