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采用分子动力学方法系统地研究了石墨烯/铜纳米复合材料的剪切力学性能,包括剪切弹性模量、剪切屈服强度、剪切破坏强度及剪切变形机制。研究发现,与单晶铜的剪切模拟相比较,石墨烯的加入显著增强了石墨烯/铜纳米复合材料的剪切强度,并且剪切强度随着石墨烯体积分数的增大而提高。复合材料中的石墨烯层与铜层产生了协同作用,即石墨烯层阻碍了铜的位错扩展,铜层限制了石墨烯的结构屈曲。对含球形缺陷的石墨烯/铜纳米复合材料的剪切性能也进行了研究。结果表明,不同位置和数量的球形小缺陷对复合材料的剪切性能影响不大,小缺陷石墨烯/铜纳米复合材料仍具有较好的性能和使用价值。但随着缺陷直径的增大,复合材料的剪切强度明显减小。
The shear mechanics properties of graphene / copper nanocomposites were systematically investigated by molecular dynamics method, including shear modulus of elasticity, shear yield strength, shear failure strength and shear deformation mechanism. It was found that the addition of graphene significantly enhanced the shear strength of graphene / copper nanocomposites compared to the shear simulation of single crystal copper, and the shear strength increased with increasing graphene volume fraction. The graphene layer in the composite material interacts with the copper layer, ie, the graphene layer hinders the dislocation propagation of copper and the copper layer limits the structural buckling of the graphene. Shear properties of graphene / copper nanocomposites containing spherical defects have also been investigated. The results show that the spherical defects with different positions and numbers have little effect on the shear properties of the composites. The small defects graphene / copper nanocomposites still have good performance and use value. However, with the increase of defect diameter, the shear strength of the composites decreases obviously.