Damage mechanism and anti-penetration performance of multi-layered explosively welded plates impacted by spherical projectile

Series of ballistic experiments and numerical simulation were adopt to analyze the anti-penetration performance of explosively welded steel/aluminum, steel/aluminum/steel and aluminum/steel/aluminum plates impacted by spherical projectile vertically in this paper. A 14.5 mm slip chamber gun was used to launch the spherical steel projectile with diameter of 6 mm and the finite element code LS-DYNA 3D was used to simulate the penetration process. The effects of layer number, thickness, combination state of the interface and strength of the plates on the anti-penetration performance and damage mechanism were analyzed based on the results of experiment and numerical simulation. The results show that the damage mechanism of the front plate and middle plate is shearing and plugging, respectively, the steel rear plate is petalling deformation and the aluminum rear plate is ductile deformation impacted by projectile vertically. The anti-penetration performance of three-layered plates is better than that of two-layered plates with the same total thickness, especially the anti-penetration performance of three-layered steel/aluminum/steel welded plates is the best. As to two-layered steel/aluminum plates, the best anti-penetration performance can be attained when the thickness ratio is about 3:1. The good accordance of numerical and experimental results indicates that the finite element method (FEM) can predict the anti-penetration performance of multi-layered explosively welded plates well.