中文摘要：

采用Tersoff势对含Stone—Wales（SW）拓扑缺陷的单层石墨烯薄膜的单向拉伸力学性能进行了分子动力学模拟，分别研究了SW拓扑缺陷对扶手椅型和锯齿型石墨烯拉伸力学性能及变形机制的影响．研究结果表明，单个SW缺陷对两种手性石墨烯薄膜的杨氏模量几乎无影响，而对薄膜的强度、应变等力学性能和变形破坏机制的影响与手性有关．对于扶手椅型石墨烯薄膜，单个SW缺陷降低了薄膜的拉伸强度和拉伸极限应变，降低幅度分别为5．04％和7．07％．在外载作用下，新的缺陷的萌生位置出现在SW缺陷附近；而对于锯齿型石墨烯薄膜，单个SW缺陷基本不影响薄膜的力学性能和变形破坏机制．

英文摘要：

The effect of Stone-Wales（SW） defects on the tensile mechanical properties and deformation mechanism of the zigzag and armchair single graphene sheets was investigated using molecular dynamics simulation with Tersoff bond-order interatomic potential. The numerical simulation results show that there is no effect on the Young＇s modulus of the two chiral graphene sheets due to the presence of single SW defect, while the effects on the tensile strength, strain and deformation mechanism are dependent on the chirality of graphene. For armchair graphene sheets, single SW defect is observed to reduce the tensile stress and limit tensile strain by as much as 5.04 % and 7.07 %, respectively. It is also found that SW defect serves as nucleation site for fracture under tension. However, for zigzag graphene sheets, single SW defect has no effect on the mechanical properties and deformation mechanism.