Energy absorbers in automobile bumper system for pedestrian safety and low-speed impact: a review

Bumper is a structure attached to the vehicle at both front and rear end to dissipate the kinetic energy generated by an impact and protect the vehicle components and its occupants. An ideal bumper energy absorbing system should be crash-worthy at both low-speed and high-speed collisions as well as meet the requirement of pedestrian safety. Energy absorbers are used between the bumper fascia and bumper beam to improve crashworthiness. Key areas of research focused to optimise the bumper energy absorbing systems are the selection of material and the structural design/geometry. Different materials and structural designs are being tried out to optimise the bumper energy absorbing system to meet the requirements. The characteristics, advantages and disadvantages of these materials and structures are reviewed in this paper.