Expert investigators are required to reconstruct the accidents involving the collision of automobiles, or of an automobile hitting a stationary obstacle or both, based on post-accident information. Post-accident information normally includes the damage of the automobiles due to the collision, the skid marks, the damage due to the obstacle, and the distance travelled by the automobiles after impact. The general transient analysis of automobile collisions, discussed in the paper, includes relative sliding, rotation, and plastic deformation of the automobiles.
Experimental methods are described to obtain the automobile parameters, i.e., center of gravity and moment of inertia. An approximate general analysis is proposed to estimate the energy lost in relative sliding and plastic deformation during impact. The movements of the occupants of the automobiles during impact are described. Simplifications can occur depending on the nature of the accident. The general analysis is specialized for these simplifications. Based on the author's experience, some examples are given to illustrate the theory.