Influence of vacancy defects on the damage mechanics of graphene nanoribbons

Using molecular dynamics simulations, graphene nanoribbons with armchair chirality were subjected to displacement-controlled uniaxial tension until complete fracture at 300K in order to understand their damage mechanics. Graphene nanoribbons with and without a vacancy defect were simulated to compare the effect of the defect on the fracture behavior. Simulations were performed for graphene nanoribbons with lengths ranging from 2.5 to 15nm. The stress-strain curve of each case is reported, and the influence of defect on the material properties is discussed. For each sample, damage mechanics types were observed and discussed. Results show a negligible effect of the single vacancy defect on the ultimate strength of the graphene nanoribbon. However, having a single vacancy defect does influence the failure strain, as well as the damage mechanics past the ultimate stress point.