▎ 摘　　要

In this paper, the effects of two main types of structural defects, i.e. Stone-Wales and single vacancy, on the mechanical properties of single-layered graphene sheets (SLGSs) are investigated. To this end, molecular dynamics simulations based on the Tersoff-Brenner potential function and Nose-Hoover thermostat technique are implemented. The results obtained have revealed that the presence of defects significantly reduces the failure strain and the intrinsic strength of SLGSs, while it has a slight effect on Young's modulus. Furthermore, the examination of loading in both armchair and zig-zag directions demonstrated that SLGSs are slightly stronger in the armchair direction and defects have lower effect in this direction. Considering the fracture mechanism, the failure process of defective and perfect graphene sheets is also presented. (C) 2011 Elsevier Ltd. All rights reserved.