Finite element analysis and molecular dynamics simulations of nanoscale crack-hole interactions in chiral graphene nanoribbons

摘要

Nanoscale defects (such as cracks, holes) often occur in graphene nanoribbons (GNRs). However, it is still a big challenge to accurately predict crack-hole interactions in them. In this study, the nanocale crack-hole interactions in chiral GNRs are investigated under mode-I loading using molecular dynamics (MD) simulations and finite element (FE) analysis. The carbon-carbon (C-C) bond in the FE method is modeled as a nonlinear Timoshenko beam based on the full-atom Reactive Empirical Bond-Order interatomic potential of second generation (REBO potential) for the first time. The present MD and FE results show that the shielding effects on the crack tip stress field are dominated by the angle is theta, the hole-to-crack tip spacing r and the chirality of the GNRs. Checking against the linear-elastic fracture mechanics (LEFM) predictions of some crack-hole configurations shows that the present FE method and MD simulations have high accuracy. This study should be of great help for understanding nanoscale crack-hole interactions in GNRs and providing physical insights into the origins of defect engineering of GNRs.