Hypervelocity impact into oblique ceramic/metal composite systems

Abstract

A numerical study for the analysis of oblique ceramic/metal composite armour systems against L/D = 20 projectiles has been performed. The ballistic performance of the add-on lightweight armours was examined by determiningthe effect of areal density of the system on ballistic limit or depth of penetration (DOP). To do this, a series of three-dimensional numerical simulations has been conduced. The impact velocities considered are 2.2 and 2.6 km/s. The oblique angle of the plate is 60 degrees. Simulation results for ballistic limits appear to match fairly well with the test values. Although the previous data for the penetration of 7.62 AP projectile into relatively thin alumina/aluminium composite targets revealed an optimum value of the front plate to back plate thickness ratio in the region of 1.5, the current data for the impact of long rod into relatively thick composite targets are scattering. This is because the distinguishing features of thin composite armour systems against 7.62 AP and 40.7g steel projectiles are crack propagation, ceramic conoid formation and failure of backing plate, while these effects are less significant in thick targets, especially at high impact velocities.