Advanced Multi-Layered Protective Systems for Defeating High Energy Projectiles

Abstract

This study aims to investigate experimentally and numerically the ballistic trauma absorption of different armor ceramics with aramid composite reinforcement. The studied ceramic materials include homogeneous alumina oxide, with different Al2O3 contents, alumina-mullite and reaction-bonded boron carbide (RBBC) ceramics where their composition, structure, and main mechanical properties are examined and analyzed. Likewise, the penetration behavior of a 7.62x39 mm Mild Steel Cored (MSC) bullet from an AK round and 7.62x51 Full Metal Jacket (FMJ) bullets was studied, since the selected armors are often subjected to such particular threats in personal body armor systems. Three dimensional FE models of the bullets and armor plates were developed to study the penetration behavior of the bullets, the fracture pattern of ceramics and to predict the Back Face Deformation (BFD) of the considered armors. It was found that the studied armors have been proved to have very acceptable protection levels due to the measured ballistic trauma, which was in accordance with standard NIJ-0101.06. Also, despite the total erosion of the 7.62x51 mm FMJ bullet during the penetration process, it has the highest recorded ballistic trauma. Blunting and mushrooming of the 7.62x39 mm MSC bullets leads to decreasing of its intrusion in the armor plates. The combination of the constitutive relations and the FE algorithms has successfully matched details of impact tests for the bullets and the armor plates that lead to the explanation of the dispersion of the BFD measures for each impact situation. The propagation of radial and circumferential cracks, fracture conoid formation has been well predicted for alumina ceramics. The highest BFD values were shown in the RBBC ceramics with the absence of residual fracture conoid after the impact.