Prediction of superior target layer configuration of armour steel, mild steel and aluminium 7075-T651 alloy against 7.62 AP projectile

Abstract

The ballistic performance of triple-layered in contact mild steel, Armox 500T steel and 7075-T651 Aluminum target plates have been studied at normal and oblique impact against 7.62 AP projectiles in order to understand the superior target configuration. The targets of layered configuration such as the high strength – low ductility (Armox 500T Steel), low strength – high ductility (Mild Steel) and medium strength – medium ductility (Aluminium 7075-T651 alloy) have been considered in the present study. The numerical results have been validated by the experiments reported in an earlier study in case of mild steel as well as Armox 500T steel whereas the 7075-T651 aluminium has been verified with the experimental results available in the literature. The Johnson-Cook elasto-viscoplastic material model calibrated by the authors for all three targets were employed in the numerical simulations. The close correlation between experimental and numerical results have been predicted. The superior target configuration has been identified from the simulation of eighteen target configurations as chosen from the present study. Further, the simulations were carried out on superior target layer configuration against varying oblique angle in order to identify the limiting velocity of projectiles and resistance of target. The results were presented in terms of stresses, residual velocity, deformations and the delamination of layers. It was concluded that the best configuration is the upper layer of low ductility – high strength material, middle layer of high ductility – low strength material and the lower layer of medium strength – medium ductility material. It was also observed that the projectile at oblique angle of maximum 35° perforates the superior layered target.