Study on transition from dwell/interface defeat to penetration of long-rod projectile impacting silicon carbide

Abstract

Dwell/interface defeat phenomenon plays a pivotal rule in enhancing the protective ability of ceramic armor. In this study, the transition from dwell to penetration was studied experimentally and numerically, focusing on the dwell time, penetration and damage evolution in ceramic. A series of depth of penetration experiments were conducted of silicon carbide impacted by tungsten–iron–nickel (93%W–Fe–Ni) conical long-rod projectile (LRP) between 900 and 1400 m/s. The transition from interface defeat to extended dwell to penetration of ceramics was observed experimentally. Data analysis suggested that instead of a sharp transition velocity above which dwell phenomenon stopped, dwells with a phase of gradual decreasing time over a range of velocities were observed in experimental work. This observation was then studied by using numerical simulation software AUTODYN with two material models, Johnson–Cook for LRP and witness target, while Johnson–Holmquist for ceramic. The results of numerical simulation agreed well with the corresponding experimental data. Significant influences of nose shape of LRP, projectile material, ratio of each layer of target structure and thickness of back plate on transition from dwell to penetration were investigated numerically. It is shown that dwell/penetration transition predominantly depends on the damage accumulation in ceramic and the performance of back plate. In addition, mass erosion of LRP, rather than the decrease of velocity, functions vitally in affecting the transition when different projectile materials are taken into consideration.