Damage mechanism and anti-penetration performance of explosively welded plates impacted by projectiles with different shapes

Abstract

The damage mechanism and anti-penetration performance of explosively welded steel/aluminum plates, which was different from common target for the well surface-to-surface combination, impacted by spherical and cubical projectiles at different incident angles were studied by ballistic experiments and numerical simulation. The total thickness of the plate is 5mm. A 14.5mm slip chamber gun was used to launch the spherical steel projectile with diameter of 6mm and cubical steel projectile with side length of 4.2mm in the experiments. Penetration process was numerically simulated by dynamic finite element program LS-DYNA3D. The effects of projectile shape, kinetic energy and target thickness distribution as well as incident angle, which is 0°, 30°, 45° and 60°, respectively, on the anti-penetration performance of the plates were investigated. The results show that when the target is penetrated by the projectile, the damage mechanism of steel front plate is shearing and plugging and that of aluminum rear plate is prolonging deformation. It is easier for the spherical projectile than the cubical projectile with the same initial kinetic energy to perforate the plates. The optimized thickness ratio of steel and aluminum is about 3:1 for spherical projectile and about 3:2 for cubical projectile. The ballistic limit velocity increased with the improvement of incident angle for both spherical and cubical projectiles. The good accordance of numerical and experimental results indicates that the finite element method (FEM) and the Tie-Break model can predict the anti-penetration performance of the explosively welded plates well.