Dynamic response of alumina ceramics impacted by long tungsten projectile

In this paper, the dynamic response characteristics of ceramic targets impacted by a long tungsten projectile at a high speed are investigated through an improved theoretical model. The model, based on conventional quasi-static cavity expansion theory, takes the effect of the target damage caused by penetration on the constitutive equation into account. A few useful relations of the target resistance and the penetration velocity are derived from the model and the stationary incompressible hydrodynamic theory. In order to examine the dynamic damage response of alumina ceramics to projectile impact and the theoretical model, we set up the experimental system of a high-speed, long tungsten projectile with its sabot separation device penetrating ceramic targets with/without cover plate, carried out a series of penetration experiments, and compared the experimental results with theoretical calculation and numerical simulation results. Theoretical and experimental results show that 1) the anti-penetration ability of AD90 ceramic is higher than that of 45# steel, especially, in the low-speed stage of the projectile; 2) material parameters of AD90 ceramic obtained from the numerical simulation of projectile penetration are reasonable; 3) the cover plate covered on the front of the ceramic target can improve the anti-penetration ability, while the constraint sleeve enclosed the ceramic target has little effect on the anti-penetration ability; 4) from the numerical simulations, the damage caused by penetration in the target with the cover plate is initiated by the tensile wave reflected from the back of ceramic, while the damage in the non-plate target is initiated by direct impact, and then develops at the target back by tensile wave; and 5) the theoretical model presented in this paper is proven to be reasonable, can be used to further studying on dynamic response of target materials under penetration.