THE BALLISTIC RESPONSE OF CERAMIC TARGETS UNDER VARIOUS CONFIGURATION AND OBLIQUITY

Abstract

The present study is focused on the ballistic evaluation of advanced ceramics (B4C and SIC) against armour piercing incendiary projectiles under normal and oblique incidences as well as under different configurations. A detailed experimental and finite element investigation has been carried out to study the material and structural behaviour of the two identified ceramics in order to explore the suitability of the ceramic-aluminium composite armour under different ballistic impact conditions. The experimental and computational results obtained in the present study with respect to thickness, angle of incidence and target configuration are pertinent with respect to the improvement in the design of ceramic based armour. The material characterisation experiments were initially performed on B4C and SIC hot-pressed ceramic materials. The density, elastic and shear moduli, flexural strength and the uniaxial compression behaviour at quasi-static and high strain rate of the two ceramic materials were studied through Archimedes method, impulse excitation of vibration method, three-point bending test, and universal compression tests performed on UTM and the split-Hopkinson pressure bar apparatus, respectively. The assessment of the ballistic resistance of the ceramic is carried out through the depth-of-penetration (DOP) experiments. The experiments were carried out on ceramic tiles of size, 100 mm × 100 mm, and thicknesses, 5 mm and 10 mm against 7.62 and 12.7 API projectiles. Two different aluminium alloys, 7075-T651 and 6061-T6, were used as the backing layer in the present study with their dimensions, 150 mm × 150 mm × 50 mm and 260 mm × 360 mm × 50 mm, respectively. The experimental setup for DOP experiment had a universal gun that was able to fire various projectiles up to 14.5 mm calibre. Ansys/Autodyn finite element (FE) explicit solver was used in the present study for the modelling, meshing and numerical analysis of high strain rate material tests as well as for the simulations of reference and residual depths of penetration. The original MSHPB used in the experiment had 2000 mm length of the incident and transmission bars. However, in order to simplify the finite element model, the length of incident and transmission bars were reduced to 1200 mm while the other components of MSHPB were modelled as per their actual dimensions. The meshing of all the components of the MSHPB as well as the B4C specimen was carried out using eight node hexahedral elements. The frictional interaction was assigned between the specimen and the inserts. The high strain rate test was numerically simulated for the striker velocity, 13.5 m/s.