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Abstract
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Knowledge of human injury tolerance levels, especially the level of impact severity likely to produce an injury,is important in the design of a crashworthy road transport system. Such knowledge can be achieved from studies of real-life impacts where the link between impact severity and injury outcome is analysed. In order to get adequate injury risk functions it is important that valid and reliable crash severity data is used.
The aim of this paper was to present injury risk functions based on real-life frontal crashes where crash severity was measured with on-board crash pulse recorders. The crash pulse recorders measure the acceleration time history in the impact phase of a collision. Results from 178 frontal collisions with an overlap of more than 25% and with an angle within +/- 30 degrees from straight frontal have been analysed. A mix of 18 car models of 4 different makes was included in the study.
The study shows the potential in using real-life data to establish injury risk functions to be used as guidelines in the design of a crashworthy road transport system. The results showed variations in the ability of explaining risk of injury depending on the crash severity parameter used. Based on the limited number of car models studied, acceleration seemed to better describe injury risk than did change of velocity in frontal impacts. In order to have lower than 25% risk of an AIS2+ injury, it was found that mean acceleration should be kept below 8 g and peak acceleration below 26 g. At every crash severity interval women were found to have a higher injury risk of AIS1 injuries than did men. Also the risk of AIS2+ injuries was found to be higher for women than for men at a crash severity above 25 km/h or 7 g. At every crash severity older drivers above 50 years age were found to have higher risk of AIS2+ injuries than had drivers below 50. Furthermore drivers were found to have higher AIS2+ injury risk than did front seat passengers at mean acceleration above 8 g. At crash severities where the airbags are likely to be deployed a large reduction in the risk of AIS1 as well as AIS2+ injuries was found.
KEY WORDS: injury risk, crash recorder, mean acceleration, peak acceleration, impact severity |