A numerical analysis on effect of impedance and thickness of various layers on deflection of target plate in layered armor systems under explosive loading

Multi-layer structures have been widely used for producing resistant structures under dynamic loads. In this article, behavior of multi-layer structures at high strain rates, their effect on the shock wave attenuation and deflection of target layer are investigated. The effect of the thickness of SiC, Al6061 and RHA steel on deflection of target layer was investigated numerically; and mathematical modeling was applied for target layer deflection. LS-DYNA software was used for simulation. The Johnson-Cook and Johnson-Holmquist material models were used for modeling of ceramics and metals, respectively. Two-layer and three-layer composite structures with a constant total thickness of layered system were simulated and their impact on the target layer deflection were studied. Due to the importance of weight factor in creation of a multi-layer armor, for better comparison of multi-layer structures, the stiffness to weight ratio was used. The results show that using two ceramic layers around metal layer increases the stiffness to weight ratio of the structure and improves armored system performance. Consequently, a four-layer system consisting of a combination of ceramics and metals was suggested which has a less weight and better performance. In this system, a reduction pattern for acoustic impedance is used which has positive impact on the performance of armored structure.