Influence of Different Factors on the Anti-Penetration Performance of Three-Layer Steel-Aluminum Composite Structure under Equal Surface Density

Based on the previous research on the anti-penetration performance of the steel-aluminum (SA) two-layer composite structure, the simulation analysis of the SA three-layer composite structure is further carried out in this paper. A SA three-layer composite structure model with equal surface density is established to explore the impact of penetration parameters of fragments, rifle bullets and target plate structure parameters on the anti-penetration performance (APP) of the composite structure was investigated. The penetration velocity varies from 820 to 930 m/s. The simulation results show that the APP of the composite structure remains unchanged when the target plates (two steel plates and one aluminum plate) with the thickness of 4.5 mm are used; With the increase of the distance between the target plates, the penetration resistance of the target plates decreases. The percentage of dissipated energy of the rifle bullets penetrating the SA three-layer composite structure decreases first and then increases with the increase of the thickness ratio, and the dissipated energy of the bullets decreases with the increase of the incident velocity and angle; When the fragments with different shapes penetrate the three-layer SA composite structure, the stress change of the cube fragment is the largest, while that of the spherical fragment is the least. By comparing the percentage of dissipated energy of bullet and fragment penetrating double layer SA target plate and three-layer SA target plate, it is concluded that the resistance to bullet and fragment penetrating performance of double layer composite structure is better than that of three-layer composite structure.