Physical Mechanism and Resistance Characteristics of Nacre-Like Composites for Two-Point Impact

The coupling mechanism of multi-point impact and the excellent structural properties of the nacre have received attention in recent years. Referring to the micro-morphology of nacre structure, a 3D model of Aluminum AA7075-T651/toughened epoxy resin is established by Voronoi algorithm, and the aluminum tablets and adhesive layers together constitute the brick-mortar structure. Based on the morphological damage characteristics of nacre-like composites to resist the blunt bullet impact, the impact resistance of composite is divided into four stages, and the coupling of two-point impact is analyzed compared to single-point impact. In addition, in order to investigate the relationship between different impact positions, four different modes of two-point impacts were established, and each impact mode was set up in three distribution forms. Based on the residual velocities of bullets, the impact resistance performance range of nacre-like composite is derived. The results show that the bullet at the center withstands the maximum resistance, and the resistance at the non-central position decreases first and then increases from the center to the boundary. This kind of composite (a 3D model of Aluminum AA7075-T651/toughened epoxy resin referring to the micro-morphology of nacre structure) has great application potential in the field of ballistic impact protection.