A novel lightweight sandwich panel with substantial resistance to ballistic penetration

摘要

The goal of this study was to develop a lightweight structural panel that also provided substantial resistance to ballistic penetration. Conventional sandwich structures consist of a low density core laminated between thin stiff facing sheets. Their specific flexural stiffness can be very high but their out-of-plane impact strength is typically so low as to barely slow a high-energy projectile. In a new configuration examined here, the standard core has been replaced by a novel hybrid structure that can redirect or dissipate most of the incoming projectile's energy. This new core consists of woven Aramid textile loosely anchored to the facing sheets by slender sacrificial pins. A numerical model of this structure was evaluated using Abaqus Explicit Nonlinear software. The initial phase of parameter study focused on the combined effects of pin modulus and strength. Various metrics were used to assess the simulated efficacy of armour test panels struck by a 5.66 mm (0.233 calibre) bullet travelling at 300 to 900 m/s (1000 to 3000 ft per s). The salient result was that the optimal choice of pin properties varied according to the chosen metric. For example, stiff weak pins maximized energy dissipation but stronger pins minimized backface deflection and softer pins minimized peak fabric stress. The overall pattern indicated that a pinned ballistic fabric core could, when suitably scaled, provide far better ballistic protection than standard core materials, with minimal weight or cost penalties.