The purpose of this study is to examine thoracic injury mechanism, and to determine the tolerance in lateral impact. The response of the thorax of the human cadaver for a total 21 sled impact tests were analyzed by using University of Heidelberg test data. The study provides a simple mathematical description of the process of thoracic deformation in lateral impact into a rigid wall or into a wall with padding. The analysis has shown that, in the case of impact against a rigid wall, the thorax displays a high velocity of deformation with relatively low compression during a short crash impulse. However, in the case of impact against the wall with soft padding, the compression becomes an important factor in the chest injury. If an injury criterion involves only one of these two factors, it will be not complete, so that it could not correctly be connected with the injury mechanism. Human thorax tolerance has been defined by the probability function of injury risk. A tolerance level of the viscous response (VC)max=1.03 m/s and of the dissipated energy response (DE)max=1.34 m/s for the chest in side impact were determined for a 25% probability of serious injury NFR=4 (number of fractured ribs). Maximum thoracic compression was similarly set at C=35.4%. (A)
Abstract