The Influence of Penetration Angle on Anti-Penetration Performance and Reverse Penetration Ricochet Phenomenon of UHMWPE Laminates

Penetration angle refers to the angle between the normal of laminates and the projectile trajectory. In actual battlefield conditions, projectiles may hit Ultra-High Molecular Weight Polyethylene fiber (referred to as UHMWPE) laminates from various angles, resulting in ricochet phenomena and secondary injuries. Currently, research on bullets hitting penetrating laminates at a perpendicular angle is relatively well-developed, while research on the penetration of laminates by bullets at other angles is limited. Therefore, this study combined experiments and numerical calculations to investigate the penetration of 7.62 mm steel core projectiles at different angles on UHMWPE laminates. The study found that UHMWPE laminates enhanced bullet resistance through yawing and bending the penetrating projectiles at different angles. The influence of penetration angle on the impact area of the projectile-facing surface, the height of the bulge on the backside, and the penetration depth, as well as the trajectory and morphology of the projectile, were mastered in this study. Notably, a penetration angle of 50° was the limit condition for projectile to produce reverse penetration ricochet phenomenon of projectiles in UHMWPE laminates with a thickness of 30 mm. These research findings provide a theoretical basis and technical support for the bulletproof design of UHMWPE laminates.