A numerical study of the energy-absorption characteristics of metal tube-reinforced polymer foams

This article investigates the energy-absorbing behaviour of lightweight foam structures reinforced with aluminium and steel cylindrical tubes. Initial testing focuses on establishing the influence of the inner diameter to thickness ratio (D/t) of the metal tubes on their specific energy-absorption characteristics under quasistatic compression and low velocity impact loading. Following this, individual metal tubes are embedded in a range of crosslinked PVC foams, and the specific energy-absorption characteristics of these reinforced systems are determined. The effect of increasing the number of tubes on the energy-absorbing response of the tube-reinforced structures is also studied. The crushing responses of both aluminium and steel structures are then predicted using the finite element analysis package Abaqus/Explicit, and the predictions of the load-displacement responses and the associated failure modes are compared to experimental results. Agreement between the numerical predictions and the experimental data is good across the range of structures investigated, with the model accurately predicting the compression response and failure characteristics observed in the structures. It has been shown that the stiffness of the foam does not significantly alter the energy-absorbing behaviour of the stiffer metal tubes, suggesting that the density of the foam should be as low as possible, whilst maintaining the structural integrity of the part.