Experimental study of perforation of multi-layered targets by hemispherical-nosed projectiles

In this paper, perforation of single and three layered metallic targets by hemispherical-nosed cylindrical projectiles are studied experimentally. The circular targets of Al 1100 have a diameter of 220 mm and the hemispherical-nosed projectiles are silver steel cylinders with a mass of 12.15 g which are hardened to 56RC. The single layer target is 3 mm thick and the thicknesses of layers of the three layered targets are 0.5, 1 and 1.5 mm. The multi-layered targets are tested both when the layers are in-contact and spaced (with air gaps). Tests are carried out using a one stage gas gun. The ballistic limit velocity is obtained and the effects of order of layers and the width of air gaps between them on the ballistic limit velocity are investigated. The results show that the single layer targets have greater ballistic limit velocities than multi-layered targets. Furthermore, the ballistic limit velocity of in-contact layered targets is greater than that of spaced layered targets.