Consideration of the elastic compressive properties of cars in frontal impact.

This paper examines on a fundamental basis the elastic deformation of car structures during frontal impact, and proposes models for the elastic stiffness of cars. The paper shows that the rebound energy and Vr, rebound velocity is a function of the impact force at the instant of maximum dynamic crush and of the elastic stiffness. Theoretical predictions of the level of Vr, rebound velocity and it's manner of variation with approach velocity, Va, for full width barrier impact are similar to the pattern of Vr, rebound velocity variation found from staged tests. The implications of the model for Vr, rebound velocity in offset collisions are reviewed, and an explanation is provided for both tangential and normal restitution coefficients at angled impact surfaces. (A)