Crushing Response of Al 7005 and 7075 Tubes against Transverse Loading

This paper addresses the energy absorption behavior of high-strength aluminum alloy tubes made of AA 7005 and AA 7075 for potential application in passenger vehicle bumper systems to reduce pedestrian injury. An experimental and numerical analysis was carried out to know the quasi-static lateral compression behavior of the tubes. The length to diameter ratio of both types of tubes was varied as 1, 1.5, and 2 for identical wall thickness (3.55 mm) and external diameter (34 mm). Influence of length to diameter ratio on specific energy absorption, average load, failure mechanism and load-displacement curve was explored experimentally as well as through three-dimensional numerical simulations. Experiments were performed through compressive testing machine (CTM) with crosshead velocity of 1.2 mm/min whereas Ansys LS-DYNA with linear plasticity material model was employed to carry out the numerical simulations. Moreover, the obtained results were compared with the analytical models available in the literature, which was based on rigid-perfectly plastic material model. The predicted results were found to be close enough to that of the experimental results as well as analytical results. Experimentation and Finite element analysis showed that the aluminum tube AA7005 has better credibility as energy absorber than tube of AA7075.