In this study MADYMO 3D has been used to evaluate the influence of the crash pulse and of seat belt usage on occupant response in rear impacts. Sled tests with the so called Rear Impact Dummy, the HYBRID III dummy equipped with a neck specially designed for rear-impact testing, were carried out and tranferred into MADYMO. The angle-moment relation of adjacent vertebrae of the neck was measured, as well as various mechanical properties of the seat back, such as the linear stiffness and the angle-moment relation of the recliner mechanism. The rearmost contact contour of the lower torso element of the dummy also had to be modified, in order to accurately model the interaction between that body part and the seat back. part and the seat back. The results showed that the risk of neck injury was higher for short duration pulses. They also showed that the seat belt was effected only when occupant ramping occurs, and that friction between the occupant and the seat back was critical to ramping.
Abstract