Crashworthiness of recycled cardboard panels reinforced with hybrid columnar aluminum tube‐GFRP rods

Abstract This article presents an experimental study on the crushing properties of recycled cardboard panels reinforced with hybrid columnar aluminum tube‐GFRP rods made by a tubular braiding method under quasi‐static compression. The effects of number of hybrid columnar aluminum tube‐GFRP rods with a taper are investigated in single‐layer cardboard panels and two‐layer panels including a thin aluminum interlayer. The results show that GFRP rods with a tapered end display much better progressive crushing behavior with larger specific energy absorption (SEA) compared with rods without a taper, with average values of 65 and 43 kJ/kg, respectively. Moreover, aluminum tubes show a concertina mode of crushing due to folding of the tube walls, with an average SEA of 89 kJ/kg. On the other hand, the highest SEA of 102 kJ/kg is obtained in hybrid columnar aluminum tube‐GFRP rods with a taper, due to interactions of the aluminum on the crushing behavior of the rods. No interactions are observed on the crushing behavior of hybrid columnar structures in cardboard; however, the cardboard does constrain the fiber splaying process of GFRP rods. The interlayer aluminum has a pronounced effect on crushing stability of GFRP rods and hybrid columnar aluminum tube‐GFRP rod reinforced two‐layer cardboard panels.