The effect of vehicle deceleration-time wave shape on the ridedown behaviour of the occupant during a right-angle crash was analysed. Ridedown benefits are dependent primarily on occupant spacing and vehicle external crush. The most direct and practical way to reduce injuries and deaths from front- end collisions is to improve the vehicle interior energy absorption behaviour. The theoretical ridedown potential of conventional vehicles can be improved by designing the structure so as to reduce the rise time of the deceleration- time history. The ridedown mechanism, is a valid means of reducing occupant impact severity. The mathematical dummy- vehicle model is described which is used to provide a reasonable evaluation of relative occupant impact severities for different vehicle crash characteristics. A computer program is available for analysis of data obtained in these studies. Data summaries are presented in tables for two different car deceleration wave shapes, for an unbelted driver in 20 mph and 30 mph barrier crashes, and for lap-belted drivers in 20 and 30 mph barrier crashes.
Abstract