On a thickness free expression for the stiffness of carbon nanotubes

A new expression for the stiffness of single-walled carbon nanotubes has been developed in this study. Three general models of single-walled carbon nanotubes (i.e., armchair, zigzag and chiral) have been used to define thickness free expressions of the nanotubes. The best curve fitting function has been obtained to describe the relation between the single-walled carbon nanotubes thickness and its stiffness. The coefficients of all three equations represent the circumferential-specific modulus. Furthermore, the stiffness of single-walled carbon nanotubes which is calculated by substitution of different assumptions for the thickness into the equations is in good agreement with the results of previous studies. The main purpose of this study is to characterize the stiffness of single-walled carbon nanotubes, based on different thickness assumptions. The focus in this study was on single-walled carbon nanotubes. Based on the structures of nanomaterials, this method can be easily applied to other atomic structures. Thickness- free expression which is studied here is in good agreement with quantum/continuum mechanics. (C) 2015 Elsevier Ltd. All rights reserved.