Due to the demands and needs for lightweight vehicles in order to improve fuel efficiency and reduce pollution, aluminium alloy has been the number one preference in material selection. Its ability to be easily extruded makes it an important factor in vehicle parts especially the frontal longitudinal members. For an energy absorber to be ideal, the initial peak force should be low while its average crushing force should be high. The aim of the present research is to achieve an improved understanding of the crushing behaviour of thin-walled structures under axial impact.