Impact perforation of steel plates

The perforation of mild steel, stainless steel and high-strength steel plates subjected to impacts characterised as low-velocity (up to about 20m/s) and moderate-velocity (20-300m/s, approximately) are examined in this paper, wherein recent experimental data and some empirical equations have been compared. The threshold velocity for the normal perforation of metal plates focuses on cylindrical projectiles with various shaped impact faces, principally flat. A new criterion is suggested to distinquish between low-velocity and moderate-velocity impacts. Empirical equations are valuable for preliminary design purposes, and are sometimes adequate for final designs. Several empirical equations, which have been developed recently, are examined for their accuracy in estimating the perforation energy of plates in the two impact velocity regimes which have been examined in this article. It is noted that there is a paucity of experimental data when recognising the plethora of parameters which control the perforation of plates. This hinders the development of empirical equations, though surprisingly accurate predictions for perforation velocities are possible to achieve, even for practical problems. Nevertheless, numerical studies are therefore required to remove many of the restrictions on the validity of empirical equations, but these methods require a considerable amount of accurate experimental data on the dynamic material properties and failure criteria.