Fracture of aluminium foam core sacrificial cladding subjected to air-blast loading

The effect of core density and cover plate thickness on the blast response of sacrificial cladding panels has been investigated through blast loading experiments and finite element modelling on structures with steel cover plates and aluminium foam cores. A range of foam core densities were examined, with 10%, 15% and 20% nominal relative densities. The cover plate thickness greatly influenced the response of the sacrificial cladding. Cover plates that were 2 mm thick exhibited significant permanent deformations and variable percentage crush across the section, whereas the 4 mm thick cover plates were more rigid causing the core to compress uniformly. Considerable fracture of the foam was observed after blast testing, particularly for the lower density foams. The effect of bonding the cover plate to the core was also examined. Numerical simulations of the experiments were performed using ABAQUS/Explicit to provide insight into the response mechanism. It was shown through the finite element simulations that tensile fracture of the foam occurred during the unloading phase of response and that adhesion of the cover plate to the foam caused higher levels of cracking. This was consistent with the experimental observations.