The influence of projectile hardness on ballistic performance

The ballistic performance of 17 penetrator materials, representing 5 distin ct steel alloys treated to various hardnesses along with one tungsten alloy , has been investigated. Residual lengths and velocities, as well as the ba llistic limit velocities, were determined experimentally for each of the: a lloy types for length-to-diameter (L/D) ratio 10 projectiles against finite -thick armor steel targets. The target thickness normalized by the projecti le diameter (T/D) was 3.55. For some of the projectile types, a harder targ et, with the same thickness, was also used. It was found that the ballistic limit velocity decreases significantly when the projectile hardness exceed s that of the target. Numerical simulations are used to investigate some of the observed trends. It is shown that the residual projectile length is se nsitive to projectile hardness; the numerical simulations reproduce this ex perimental observation. However, the observed trend in residual velocity as a function of projectile hardness is not reproduced in the numerical simul ations unless a material model is invoked. It is assumed that the plastic w ork per unit volume is approximately a constant, that is, there is a trade off between strength and ductility. Using this model, the numerical simulat ions reproduce the experimentally observed trend. (C) 1999 Elsevier Science Ltd. All rights reserved.