Energy loss in vehicle to vehicle oblique impact

Since the seventies, many methodologies have been developed for estimating from energy loss the delta V produced in a vehicle to vehicle impact. Normal energy loss, is calculated by a discrete number of residual crush measurements in the direction parallel to the vehicle's axis, using the stiffness coefficients. In the case of oblique impact, a correction factor is applied to the normal energy loss to determine energy loss in the impulse direction. In this paper the concept of principal direction of deformation is introduced, presenting a new method for estimating energy loss in vehicle to vehicle collision, starting from a discrete number of crush measurements, which are, however, performed considering the effective displacement of the points during the crush. This novel approach, in addition to providing a more rigorous model of the physical phenomena, leads to improvement in the results: with the new approach, the mean error committed in estimating energy loss is about 10%, as compared to the 20% of the previous methodology.