Penetration-Blast Coupled Damage Behavior of Reactive Explosively Formed Projectiles

The sequential penetration-blast damage effects of reactive explosively formed projectiles (EFP) on armored targets are investigate. The static detonation experiment is conducted on the multilayer targets subjected to shaped charges with PTFE/Al (mass ratio of 73.5%/26.5%) reactive spherical-segment liners. The results indicate that the reactive EFP formed a penetration hole with a diameter of approximately 0.6 times the charge diameter in a 10 mm-thick front steel target at a charge diameter of 50 mm, caused severe blast-induced damage to the behind aluminum target, and generated a peak overpressure of 1.51 MPa within a confined volume of 13 L. Furthermore, the reaction relaxation time of the reactive material was determined to be τ = 72.5 μs based on numerical simulations. A segmented SPH-FEM computational model for penetration-blast coupling is established, enabling systematic analysis of the influence of key geometric parameters of the reactive spherical-segment liner—including the inner curvature radius (R₂), outer curvature radius (R₁), and thickness (h)—on the penetration-blast coupled damage effect. The results demonstrate that the synergistic interaction between kinetic energy penetration and chemical energy release significantly enhances the damage effect of reactive EFPs on multilayer targets. Specifically, the outer curvature radius (R₁) is a critical parameter affecting the density of perforation distribution in the behind aluminum target. The increase in the inner curvature radius (R₂) within the range of 45-60 mm can enhance the hole enlargement effect on the front steel target, but it concurrently leads to a decreasing trend in the damage diameter in the behind aluminum target. As the liner thickness (h) increases from 3.0 mm to 6.0 mm, the damage diameter of the behind aluminum target exhibits a nonlinear variation pattern—increasing first and then decreasing—with the most significant damage effect observed at h = 4.0 mm.