Energy Consumption of Composite Double-Layer Targets against Spherical Fragment Penetration

In order to study the factors affecting the anti-elastic energy of the composite double-layer targets, a tungsten alloy spherical fragment with a diameter of 9.5 mm and a mass of 8.05 g was used to penetrate the single layer and the superimposed double Q235 targets with different combinations, which were kept 7.2 mm in total thickness. The experimental results show that the ballistic limit of (3.6 + 3.6) mm targets is the highest, followed by (5.4 + 1.8) mm targets, and (1.8 + 5.4) mm targets, which is the lowest. The ballistic limit of the penetration monolayer 7.2 mm target is basically the same as that of the (5.4 + 1.8) mm superimposed target. It is also found that the failure and energy consumption modes of superimposed targets vary with different arrangements. When both the two layers of the targets produce slug failure, the compression and sag energy dissipations together affect the elastic energy of the targets. However, when the current target is punch failure and the rear target reaming failure, only the sag energy dissipation is the main factor affecting its elastic energy. According to the energy consumption calculation of multiple combination targets, the arrangement of (3.6 + 3.6) mm turns to be the optimal combination under the conditions of this study. The results are of great reference value to the design of protective device.