Experimental investigation on the ballistic resistance of polymer-aluminum laminated plates

Abstract

An experimental investigation on four kinds of polymer-aluminum laminated plates impacted by blunt- and ogival-nosed projectiles was carried out. The polycarbonate (PC) layer (2 mm) and the polymethyl methacrylate (PMMA) layer (2 mm) were used to make an array with the AA2024-T4 layer (2 mm), respectively, constituting these double layered polymer-aluminum laminated plates with no adherence. To better understand the strength and ductility difference among these materials, quasi-static tensile tests were conducted for them. The impact tests of pure AA2024-T4 layer (3 mm) which has close areal density with the bi-layered plates were compared in ballistic resistance. In each impact test, the projectile was driven by a gas-powered gun at impact velocities above and below the ballistic limit velocity of the target plates, mainly ranging from 60–150 m/s. And the initial and residual velocities of the projectiles impacting the targets were measured by a Photron FASTCAM SA5 high-speed camera. Based on these results, the ballistic limit velocities of seven kinds of structures (including three kinds of different thickness aluminum layer) impacted by blunt- and ogival-nosed projectiles were obtained. And after the impact tests, the plastic deformation of the aluminum alloy in each bi-layered structure was measured.It is shown that the polymer layer order, nose shape and polymer mechanical behavior affects the performance of the polymer-aluminum laminated plates. The PC is much better than the PMMA in the bi-layer plates in terms of improving the ballistic resistance of the aluminum. Furthermore, the structures with the polymer placed in the impact side performed better than that in the back side for blunt-nosed projectiles, which is opposite to that for ogival-nosed projectiles. And the polymer-aluminum laminated plates with the PC placed in the impact side for blunt-nosed projectiles have advantages comparing with pure aluminum alloy at same mass in this study.