Ballistic resistance of multilayer composite plates comprising soft, hard, and porous materials

Multilayer composite plates, incorporating soft, hard, and porous materials, are proposed to further enhance the ballistic resistance of sandwich plates. It remains a challenge to understand the synergy of these three kinds of materials on the ballistic resistance due to the diverse configurations of these layers. In the present paper, multilayer composite plates with various configurations are proposed and designed, which consist of two rubber layers, two aluminum plates, and an aluminum foam core. With the aid of the 3D-Voronoi algorithm, finite element models of the multilayer composite plates are developed and validated based on the previous experimental results to reveal the protection mechanism. The dynamic response process, failure modes, and energy absorption are discussed detailly for all these configurations. The results show that the incorporation of soft materials dramatically improves the ballistic resistance of the conventional sandwich structure, and the improvement relies on the relative locations of each component. The synergy of soft, hard, and porous materials on the ballistic resistance includes three mechanisms: the stretching of the rubber layer, the tearing of the aluminum plate, and the compressing of the foam core. This work provides a basic understanding of the protection mechanisms of soft, hard, and porous materials, and suggests a novel strategy for designing advanced protective structures and repairing conventional sandwich structures.