Structural performance of aluminum foam-filled multi-cell steel tubes under axial impact

This study aims to investigate the structural resistance of aluminum foam-filled multi-cell steel tubes. Twentyfour aluminum foam-filled square steel tubes (AFFST) were tested using a drop hammer impact test machine. The deformation characteristics, impact force, and deflection during the impact process were then analyzed. The influence of different parameters on the axial impact performance was explored. In addition, the impact processes were simulated using finite element models to examine the effects of aspect ratio, specific energy absorption, and interface. The results indicate that, compared to single-cell AFFST, multi-cell AFFST enhanced the stiffness, with the maximum displacement reduced by 69.8 %. With the increase in wall thickness of the multicell AFFST, their cross-sectional stiffness reduced the oscillation phase of impact force. The increase in the aspect ratio improved the energy absorption capacity of AFFST by up to 252 %. Additionally, bonding between aluminum foam and the steel tube can also improve the impact resistance of AFFST, with an increase of about 80 % for single-cell AFFST and 53 % for multi-cell AFFST. Thus, the study concludes that multi-cell AFFST is an excellent energy absorption solution that can be used in structures.