Response of filled thin-walled square tubes to axial impact load

摘要

This paper presents the results of an investigation into the response of thin-walled square (60×60 mm and 76×76 mm) tubes made from mild steel filled with four different fillers; aluminium foam (Cymat 7%), two types of aluminium honeycomb and polyurethane foam to quasi-static and dynamic axial impact load. The energy absorption characteristics of the foam-filled tubes are compared to that of a hollow tube, through efficiency calculations. The tubular structures are subjected to axial impact load generated by drop masses of 320 kg and 390 kg released from a height ranging between 2.1 m to 4.1 m. Footage from a high speed camera is used to determine the average crush forces exerted by each specimen. The results show that the fillers have insignificant effects on the initial peak forces based on the quasi-static results but increase the overall mean crushed force. The findings also indicate that the fillers affect at times the size of the lobe formed thus compromising the energy absorption capacity of the tube.