Numerical investigation on dynamic damage behavior of a novel N-shaped perforated armor plate under ballistic impact

Armor steel is widely used for ballistic resistance in military infrastructures and vehicles. However, the high areal density of monolithic steel plates presents challenges in balancing protection and maneuverability. This study focuses on a novel armor design, invented by the authors: An N-shaped perforated armor plate (NPAP). The NPAP consists of a perforated plate, an inclined plate, and a back plate. A validated finite element (FE) model was used to analyze the dynamic damage behavior of the NPAP target and projectile under ballistic impact. Numerical simulation revealed that the NPAP target combined the edge and obliquity effects, resulting in asymmetric interaction and causing yaw and fracture of the projectile. The kinetic energy of the steel core after penetrating the NPAP target decreased by 84.7-88.0% compared to the initial kinetic energy. The NPAP target showed a 20.7-43.9% lower residual depth of penetration (RDOP) compared to the monolithic target. Furthermore, the effects of the dip angle of the inclined plate and plate thickness configurations on the ballistic performance of NPAP were examined. The results indicated that the NPAP target's ballistic performance is more susceptible to the impact location on the perforated plate with a larger dip angle of the inclined plate. Additionally, the NPAP target with a thin perforated plate and a thick back plate configuration exhibited better ballistic performance, given the constant thickness of the inclined plate.