基于分子动力学模拟的含缺陷石墨烯力学性能的研究

基于分子动力学模拟的方法，研究了空位缺陷的位置、形状以及原子缺失率对石墨烯杨氏模量的影响。研究结果表明，单空位缺陷的位置对石墨烯杨氏模量有一定的影响，当施加应力方向与边缘缺陷的截面方向相同时，边缘缺陷比中间缺陷使得石墨烯的杨氏模量下降更少。研究结果还发现，映射横向长条状缺陷、映射纵向长条状缺陷、映射圆孔状缺陷和随机缺陷都使得石墨烯杨氏模量随着原子缺失率的增大而减小。对于映射圆孔状缺陷和随机缺陷，锯齿型石墨烯杨氏模量减小的幅度与扶手型的减小幅度相差不大。对于映射横向长条状缺陷和映射纵向长条状缺陷，锯齿型和扶手型石墨烯杨氏模量的减小幅度相差较大，这与石墨烯的手性矢量方向和条状缺陷方向是否一致有关。

A Study on Mechanical Properties of Graphene with Defects Based on Molecular Dynamics Simulation

Based on molecular dynamics simulation, the effects of vacancy location, shape and atom deletion rate on Young''s modulus of graphene were investigated. The results show that the position of single vacancy defect has a certain effect on Young''s modulus of graphene, and when the applied stress direction is the same as the cross-section direction of the edge vacancy defect, the Young''s modulus of graphene decreases less with the edge vacancy defect than with the middle vacancy defect. It is also found that the Young''s modulus of graphene decreases with the increase of atom deletion rate due to mapped transverse long strip vacancy defects, mapped longitudinal long strip vacancy defects, mapped circular hole vacancy defects and random vacancy defects. For mapped circular hole vacancy defects and random vacancy defects, the decrease of Young''s modulus of zigzag graphene is similar to that of armchair graphene. For the mapped transverse and longitudinal strip vacancy defects, the decrease ranges of the Young''s modulus of zigzag and armchair graphene are quite different, which is related to whether the orientation of chiral vector of graphene is consistent with that of strip vacancy defect.