Experimental and numerical investigation of ballistic behavior of hybrid composite structures containing armor steel

Armor steels offer advantages such as high toughness, good strength, weldability and formability. On the other hand, aramid fibres are preferred as ballistic armour materials because they have a strong chemical bond structure between their molecules and offer high tensile strength value compared to their weight. In this study, Armox 500T and Hardox 450 armour steels, Kevlar 29 / epoxy laminate composite and aluminium honeycomb materials were used. The ballistic performance of 23 different armour structures consisting of single, double and hybrid formed by arranging these materials in different shapes was examined. Ballistics tests were carried out with 7.62 full metal jacket bullet having a muzzle velocity of 838 ± 15m/s within the scope of NIJ 0108.01 III protection level standard. Finite element analyses of the armour structures were performed in the ANSYS LS DYNA program. The test plates had dimensions of 250×250mm and their thicknesses varied between 4mm and 38.7 mm. The test plates to be subjected to ballistics tests were fixed on their four edges. Hybrid armour systems, including 4mm armour steel, which can replace 6 mm monolithic armour steel plates and provide a weight benefit, have been reported. All hybrid structures using a Hardox 450 impact face failed; however, the Armox 500T front-faced 4A14K plate and A12K10B plates have been found to be potential replacements for the 6A monolithic plate due to their weight advantage.