Spallation of targets subjected to vertical penetraion of explosively-formed projectiles

In order to understand the spallation of a target subjected to the impact load of an explosively formed projectile (EFP), on the basis of wave mechanics and basic assumptions, a mechanical model was developed to describe the spallation of the finite-thickness target vertically penetrated by an EFP. By the developed model, the spallation process of the target plate was obtained, and its formula was derived. The result shows as following. When the impact velocity of the EFP is 1 800 m/s and the thickness of the target increases from 35 mm to 60 mm, the thickness of the falcate spallation zone at the back of the target increases and its length decreases. When the thickness of the target is 40 mm and the impact velocity increases from 1 600 m/s to 1 900 m/s, the thickness of the falcate spallation zone at the back of the target decreases and its length increases. Dynamic tests were carried out on the EFPs penetration into the rolled homogeneous armor targets with the thickness of 40 mm. The experimental result is in good agreement with the theoretical prediction.