A Hybrid Material Automotive Bumper Beam for Enhanced Safety of Both Occupant and Pedestrian
In vehicle accident, the bumper beam generally requires high stiffness for sufficient survival space for occupants while it may cause serious pedestrian lower extremity injuries. The aim of this study is to promote an aluminum-steel hybrid material double-hat bumper to meet the comprehensive requirements. The proposed hybrid bumper beam is comprised of an aluminum alloy upper hat and a high strength steel (HSS) lower hat. The two hats are riveted together by steel rivets. The hybrid bumper is designed to improve the frontal crash and pedestrian protection performances in collision accidents. In a low-velocity impact scenario with a pedestrian, the aluminum upper hat helps to reduce the lower extremity injuries of the pedestrian, while in a high-velocity impact case with a rigid object, e.g., a tree or electric pole, the HSS lower hat could prevent excessive intrusion into the engine compartment and the passenger compartment, so as to prevent occupant injury.