Effect of Curvature on the Mechanical Properties of Graphene: A Density Functional Tight-binding Approach

Due to the high cost of experimental analyses, researchers used atomistic modeling methods for predicting the mechanical behavior of the materials in the fields of nanotechnology. In the pre-sent study the Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) was used to calculate Young's moduli and average potential energy of the straight and curved graphenes with different curvature widths under axial strain. Also, this method was used to determine the magnitude of the curvature on the aforementioned mechanical properties. From the results it can be concluded that Young's moduli of straight graphene is equal to 1.3 TPa and this mechanical property decreases slowly by decreasing the curvature width of graphenes. Also, the average potential energy and Young's modulus of graphenes decrease with increasing the number of curvature. In next section the Young's moduli of one-atom vacancy and two-atom vacancy defect were calculated and it was found that this mechanical property decreased with increasing the number of atom vacancy in the curved graphene.