ABSTRACT
This chapter presents a three-dimensional numerical study to determine the ballistic performance of aluminium alloy 7075-T6. The aluminium plate has a size of 100 mm × 100 mm and a uniform thickness of 6 mm. The target plate has been subjected to oblique projectile impact at three different angles. The angles of impact considered are 75°, 60° and 45°. Typical observations have been compared with normal impact cases. The shape of the projectile nose and its velocity (700–1,500 m/s) are other parameters investigated in this study. Two different projectiles with calibre radius head (CRH) 1 and 3 have been considered. The Johnson-Cook (JC) elasto-viscoplastic model available in ABAQUS is used for the projectile as well as the target aluminium plate. On the other hand, the mass (7.85 g) and the diameter (7.62 mm) of the projectile are kept consistent for all the simulations. The fixed boundary condition has been assigned to all four edges of the plates. The ballistic limit for CRH3 is observed to be about 10% lesser compared to CRH1. The lowest ballistic limit is observed at 75° impact for both projectiles. The velocity drop of the projectile is found to be relatively faster with the reduction in impact velocity. The exit velocity of the projectile has increased with an increase in impact velocity. The target plate absorbed more energy in the case of the CRH3 projectile as compared to the CRH1 projectile. Also, energy absorption has increased with a decrease in the angle of impact. The damage caused by the CRH1 projectile is noticed as being higher as compared to the CRH3 projectile. And the shape of the perforation hole has changed from circular to ovular/elliptical configuration with the decrease in angle of impact.
