Computational assessment of Stone-Wales defects on the elastic modulus and vibration response of graphene sheets

Abstract

In this work we assess the influence of Stone-Wales defects on the elastic modulus and vibration responses of single-layered graphene sheets. To this end, the atomic position of the C-atoms within the defective layers are inserted as initial conditions into finite element calculations used to estimate the mechanical properties and natural frequencies of carbon monolayers. Moreover, we consider two sets of initial atomic positions: the harmonic solution predicted by discrete dislocation theory and its fully-relaxed configuration, which is a novelty in this type of study. Thus, the mechanical properties of the beam elements are depicted based on the equivalence between the interatomic potential energy of the atomic model and the strain energy of the equivalent continuum model. Furthermore, based on the results, we propose an extension of the classical beam model that accurately defines the mechanical properties of the elements in terms of the actual length of each atomic bond. The finite element model is implemented in the commercial software Abaqus/Standard. The results obtained are in reasonable agreement with previous data presented by other authors. In this work we have specifically ascertained the importance of using a non-linear model to predict the Young’s modulus and vibration responses of defective graphene sheets.