Exploring the impact resistance of hybrid sandwich composite body armor through experimental analysis

Abstract

Hybrid composite sandwich structures, known for remarkable energy absorption, rigidity, and strength, are emerging as a preferred choice for fortifying structures against a diverse range of firearms and artillery. Despite their higher density, these panels demonstrate commendable qualities, making them optimal for armored vehicles and body armor. Numerous structural options compete for recognition as effective ballistic shields in today's context.  In this study, three sample configurations were rigorously tested for ballistic impact using a 7.62×39 mm bullet. The first sample (S1) comprised silicon carbide ceramic tiles (SiC), Kevlar fiber, and carbon fiber in the face sheet, with an unfilled aluminum honeycomb core and a carbon fiber rear sheet. Subsequent samples, S2 and S3, maintained the S1 composition but varied in the core. S2 had a honeycomb core injected with polyurethane foam, while S3 utilized a silicone rubber-filled honeycomb core. Ballistic tests revealed a notable difference: S1 and S2 failed to prevent bullet penetration, whereas S3 successfully met this crucial objective. After penetration, the bullets' velocities were S1 -45.9 m/s, S2-22.9 m/s, and S3 -0m/s. Remarkably, S3 exhibited an optimal 0mm back face signature (BFS) and a penetration depth (DOP) of 13.74 mm, well within limits. Cumulative energy absorption (EA) was as follows: S1-2577.23 J, S2-2583.57 J, and S3-2617.92 J. The armors demonstrated specific energy absorptions (SEA) of 2386.33, 2389.97, and 2015.32 J/kg, respectively. Their areal densities were 48, 48.1, and 57 kg/m2, respectively. The ballistic limit velocities (BLV), derived from initial (IV) and residual velocities (RV), measured 802.68, 803.673, and 804 m/s for S1, S2, and S3.

Keywords

• ballistic impact
• 7.62×39 mm bullet
• hybrid sandwich armor
• energy absorption
• back face signature