In frontal collisions, injury risk can be reduced if the front body structure is able to absorb a greater amount of energy. In general, however, in front-to-front collisions between different-size vehicles, the smaller, lighter vehicle sustains greater damage than the larger, heavier one. To help improve vehicle compatibility in front-to-front collisions between such vehicles, what is required is better matching of the geometry and stiffness of the front structures of the colliding vehicles.

Several methods of measuring the geometry and stiffness of front structures have previously been reported. Among these are the AHOF400 and Kw400 metrics, which are measured in full-frontal rigid barrier tests using high-resolution barrier load cells. This paper proposes an improved method for evaluating compatibility in full-frontal rigid barrier tests based on a review of the purposes of and issues with the AHOF400 and Kw400 metrics.

The methods proposed in this paper are intended to help provide an improved compatibility assessment compared with the AHOF400 and Kw400 metrics by evaluating the forces on load cells in an area defined as the structural interaction zone. Like AHOF400 and Kw400, the aim of this research is to improve structural engagement and energy sharing in the event of a front-to-front collision.