Compartment intrusion and partner protection have gained attention in traffic safety. A better understanding of compatibility effects could highlight safety priority and improve occupant protection. For this purpose, the individual effects of car structural, mass, stiffness and geometrical compatibility were studied for their effect on compartment intrusion and overall protection. First, an epidemiological study was carried out with Volvo accident material to determine the effect of overlap amount on injury risk in frontal offset crashes. Age, gender effects and impact severity biases were minimized. In crashes with an EBS > 20 mph, most injuries were caused by frontal crashes wity 1/3 to 2/3 overlap, while the highest risk was found for less then 1/3 overlap crashes. The results indicate that a test with 40% overlap would address the highest injury frequency and risk. A mathematical model was then developed to study mass effects on occupant, partner and total fatality rates. The results showed that a bimodal car fleet would strongly increase fatality rates. The fatality rate also increased when the cars were downsized to a 300 kg ligher fleet, but the transition strategy could limit the total number of fatalities during downsizing. The higher fatality rate of a ligher fleet could be compensated by small improvements in inherent vehicle protection or by impact speed reductions. Finally, a theoretical approach was used to study stiffness effects on occupant and partner protection in frontal offset and side impacts. An example of a stiff, light car showed that the occupant responses were within tolerance limits, while the aggressivity of this car was lower than that of current heavy cars. (A)
Samenvatting