Effect of Projectile Nose Angle on Resistance of Aluminium Target Against Oblique Impact

In today’s world, when it comes to the design of things like bulletproof jackets, armoured vehicles, bunkers, and the like, one of the primary concerns is safety. This is especially true in the aggressive technology sector, which includes the defence industry. In this chapter, a numerical investigation was carried out to study the ballistic performance of an aluminium plate (Al-7075 T6) when subjected to an oblique impact by a projectile with a conical shape. For modelling and simulating the current issue, the Abaqus finite-element code was utilized. In the current investigation, the nose angles of the cylindro-conical projectiles that were taken into consideration were 90° and 150°, respectively. For this particular study, it was assumed that the length, width, and thickness of the target plate, as well as the radius and mass of the projectile, would remain unchanged. The obliquity angles for impact were 15°, 30° and 45°. The residual velocity of the 150° nose angle projectile was higher than 90 nose angle projectiles at 15° obliquity. The residual velocity was decreased with increase in obliquity angle. At the ballistic limit (i.e. 750 m/s), the projectile’s energy dissipation was at its highest, which was 93% for a nose angle of 90° and 86% for a nose angle of 150°. The loss of energy was observed to be increasing with increasing obliquity. In addition, a longer amount of time was necessary to achieve the minimum value of kinetic energy when the obliquity was set at 45° rather than 15°. The plate offered higher reaction forces for projectiles with nose angles of 150° compared to those with nose angles of 90°. Additionally, the reaction forces of the plate decreased with an increase in the angle of obliquity. The size of the hole caused by a projectile with a nose angle of 90° was greater than that caused by a projectile with a nose angle of 150°. Petalling and plugging were both contributing factors in the failure of the plate, which was caused by both types of projectiles. The shape of the hole changed from circular to ovular with increasing obliquity.