Ballistic performance of asymmetric sandwich plates incorporating an elastomer

Asymmetric sandwich structures incorporating an elastomer are developed to improve ballistic performance. The mechanism of enhancement remains unclear due to diverse structural failure modes associated with asymmetric configurations. Comprising a rubber layer, two aluminum face-sheets, and an aluminum foam core, some asymmetric sandwich plates incorporating an elastomer are designed with different thickness distributions of the face-sheets. The ballistic performance of asymmetric sandwich plates incorporating an elastomer is numerically investigated using a three-dimensional Voronoi-based approach and verified against previous experimental results. The role of the rubber layer, the structural response history, failure modes, and energy absorption characteristics of each component are thoroughly analyzed. It indicates that the enhancement effect of the elastomer depends on the structural asymmetric design and the failure mode of the elastomer. When the elastomer fails primarily through stretching, it promotes synergistic interaction between the face-sheet and foam core, reducing the residual projectile velocity by 36.4% and increasing the energy absorption capacity by 233.98%. Conversely, when the failure mode shifts to shearing-dominated failure, the enhancement effect is significantly reduced. In addition, the failure mode of the elastomer depends on the interaction between its local stiffness and the initial velocity. This study provides a fundamental understanding of the mechanisms by which elastomers enhance the performance of asymmetric sandwich structures, offering valuable insights for the design and optimization of multilayer protective systems.