Impact center and restitution coefficients for accident reconstruction

Based on a previously presented two-dimensional car-to-car impact model, automobile collision tests were analyzed to understand the relationship of the impact center to the residual vehicle deformation. This is essential for improving the reliability of the impact model. The results from a number of automobile collision tests indicated that the impact centers of the two vehicles at the end of collision were located near the center of the contacting surface when the vehicle deformation is maximized. This leads to a method of defining the impact center from the crush profile at the time of maximum deformation. The relationships of the normal and tangential restitution coefficients to the collision type were also presented, discussed and evaluated to obtain some guidelines on how to choose the restitution coefficients from impact conditions.