▎ 摘　　要

Combining two or more materials with different properties, the composites can not only inherit the advantages of the original components, but also play a synergistic effect, and then produce more excellent performance. In this paper, the numerical models of three types of layered composites were established, and then the geometric imperfections (circular and square nanopore) were created in layered composites. By using molecular dynamics method, the mechanical properties of defective layered composites have been studied, and the effects of dimensions, numbers and position of defects on mechanical properties have also been investigated. Finally, the strengthening effects of graphene and other 2D materials on mechanical properties of copper were compared. The results show that the mechanical properties of layered nanostructures generally decrease with the increase in the size of nanoholes. It can be observed that the negative effect of circular nanoholes on mechanical properties of layered nanostructures is weaker than that of square nanoholes. As a result, an important conclusion can be achieved that these hexagonal rings of defective BN/Cu/BN layered nanostructure is easily destroyed and decomposed than that of defective G/Cu/G layered nanostructure. Ultimately, it can be concluded that these nanoholes are best placed in G/Cu/G layered nanostructure when nanoholes are formed in the layered structure.