Contribution of high strength steels to the absorption of impact energy^*

Abstract

During collisions, collapse of the front end vehicles into the passenger compartment endangers their occupants. To avoid this situation, dynamic energy must be absorbed by deformation of the front part, principally by the side members of the structure. Increasing thickness can solve the problem but automotive designers are obliged to reduce weight of automotive structures to save energy and to reduce production costs. There has been thus considerable interest in the use of steels with high yield stress and high tensile strength.

But, stamp forming becomes more difficult. High Strength Low Alloyed Steels (HSLA) have the required mechanical properties, but there are other possibilities of improving forming performances by using steels which have the same properties but exhibiting a much better work hardening and a good uniform elongation. This investigation aims at comparing the behaviour of many steels as mild steels, HSLA steels, Dual Phase steels in such crash situations.