Test and estimation of ballistic armor performance for recent naval ship structural materials

TLDR

Ballistic testing and thickness estimation for modern naval ship hull materials have been scarcely studied. The study aims to evaluate ballistic armor performance and estimate required thickness for Korea’s newest naval ship hull materials. The authors tested AH36 steel, AL5083, AL5086, and FRP against a 7.62 × 39 mm AK‑47 projectile and applied Tate and Alekseevskii’s penetration algorithm to calculate correction factors and estimate armor thickness at given impact velocities. Live‑fire experiments showed the proposed thickness estimates differed from measured values by 0.6 % for AH36, 0.4 % for AL5083, 0 % for AL5086, and 8.0 % for FRP.

Abstract

This paper presents the ballistic armor performance examination and thickness estimation for the latest naval ship structure materials in the Republic of Korea. Up to date, research regarding methods of ballistic experiments establishing database on the latest hull structure materials as well as a precise method of estimating required thickness of armor against specific projectiles have been rarely researched. In order to build a database and estimate proper thicknesses of structure materials, this study used four structure materials that have been widely applied in naval ships such as AH36 steel, AL5083, AL5086, and Fiber Reinforced Plastics (FRP). A 7.62 × 39 mm mild steel core bullet normally fired by AK-47 gun was considered as a threat due to its representativeness. Tate and Alekseevskii's penetration algorithm was also used to calculate a correction factor (α) and then estimate the armor thickness of naval ship hull structure materials with a given impact velocity. Through live fire experiments, the proposed method performance difference was measured to be 0.6% in AH36, 0.4% in AL5083, 0.0% in AL5086, and 8.0% in FRP compared with the experiment results.