Blast Resistance Of Sandwich Cylinders Cored With Gradient Aluminum Foam Under Internal Blast Loading: Numerical Study

Aluminum foam is a kind of novel porous material with unique microscopic structure.Aluminum foam has excellent performance in impact resistance and energy absorption.Foam materials with gradient have uneven distribution of density.They can perform better than homogeneous foam materials by design of gradient.Composite structure consisted of cylindrical aluminum foam and metal sheets is called sandwich cylinders.Sandwich cylinders cored with gradient foam were discussed in this paper.Effects of factors on blast resistance under internal blast loading were analyzed.First,based on Voronoi technique,2D-finite element model of sandwich cylinders cored with aluminum foam was constructed.Second,experiments under internal blast loading with different relative density and blast load were performed.Then,effectiveness of the element model was confirmed by contrasting results of simulations and experiments.Last,the finite element model was used to analysis the effects of relative density and cell characteristic size on blast resistance,which was reflected by energy absorption and deflection of outer sheet.The investigation results show that the simulation results agree well with the experiment results.Cell characteristic size has little effect on energy absorption.But with increasing of cell characteristic size,deflections of inner and outer sheets increase obviously.For homogeneous cores,with increasing of relative density,energy absorption per unit mass decreases linearly,and deflections of outer sheets increase slightly.Cores with negative gradient have better performance than cores with positive gradient on energy absorption and deflection of sheets.