Mode-I stress intensity factor in single layer graphene sheets

We use the freely available software, LAMMPS, and the Tersoff potential to find the mode-I stress intensity factor during crack propagation in an edge-cracked single layer graphene sheet deformed at a constant axial strain rate. The axial stress and the stress intensity factor (SIF) at atoms' locations are computed by using, respectively, the Virial theorem and either the stress at the atom located at the crack-tip or the average axial stress in the sheet. It is found that the two values of the SIF differ from each other by about 8%, and agree with those reported in the literature derived either analytically or from test data. The method proposed and used herein can be applied to find the SIF in any nanostructure. (C) 2016 Elsevier B.V. All rights reserved.