Experimental study of the fragmentation of hard cores of wolfram carbide during penetration in armour steel plates

Abstract

Numerical codes,e.g. Autodyn are widely used for simulation purposes during impact and penetration of projectiles into targets. To validate the computer simulations, an experimental study of fracturing of sintered wolfram carbide-cobalt penetrators have been carried out by shooting inert 12.7 mm MP projectiles into armour steel plates of thickness 22 mm. We found that with an impact velocity of 950 m/s the hard core penetrated the 22 mm target but fractured. The fracturing most likely took place late in the target or during exit of target. For 820 m/s impact velocity the hard core was observed to penetrate the target. But some shots (25%) indicates undamaged hard cores. The fracturing at 820 m/s most likely took place very late or during exit of target. By studying the fragmentation pattern in the witness plate behind the target, we found that some of the hard cores were weakened due to the penetration through the target, but most likely appear visually as intact. In general the results indicate that the strength of the hard core is marginal. The different penetration scenarios suggest that the penetration capabilities will be reduced when increasing the impact velocity above 950 m/s due to increased damage of the hard core. Also, increased target strength can reduce the penetration capability significantly.