A study on deformation and failure behavior of B 4 C/UHMWPE composite plate subjected to high-velocity impact

Abstract

Lightweight composite materials are used as personal body armor due to their high specific strength and stiffness. Also, a composite material’s components can be tailored as per functional requirements. In this study, B₄C/UHMWPE composite plates were fabricated to defeat 7.62 × 39 mm hardened steel core projectiles. The front-facing B₄C tiles were used to erode the hardened steel projectile, and the backing UHMWPE composite laminates were used to defeat the eroded projectile. Hexagonal tiles of hot-pressed B₄C were adhesively bonded to a prefabricated UHMWPE composite laminate in an autoclave. The UHMWPE composite laminate was fabricated using a compression molding machine. The thickness of B₄C tiles was fixed, and the thickness of the UHMWPE composite was varied during the study to understand the defeat and penetration of the composite plate. The high-velocity impact tests were conducted in a single-stage gas gun at 700 ± 15 m s^-1. It was noticed that an impacted tile cracked and failed upon impact, but damage also spread to the adjacent tiles. It was also noticed from the examination of recovered projectile cores that only the cores eroded to certain lengths and certain weights were defeated by the composite armor. A numerical simulation was performed using the Johnson-Holmquist model for B₄C and a strength-based orthotropic failure model for UHMWPE composite laminate. The model was used to understand the role of each component of the composite plate.