Size and displacement combining detection on physics properties of carbon nanotubes using a proposed energy approach

Abstract

In this paper, a coupling of advanced molecular structural model with energy method is developed to calculate the mechanical properties of single-walled carbon nanotubes (SWCNTs). The energy of a system is expressed by an advanced force field of molecular mechanics. Under the assumption of a small deformation and the principle of minimum potential energy, closed form formations are derived for temperature-dependent Young's modulus, Poisson's ratio, and bulk modulus, which are the functions of the length of C-C bonds and the out-plane displacement. The results show that the effects of tube diameter and out-plane displacement on the elastic properties of carbon nanotubes is significant when the tube diameter is small. Moreover, the principle of force-heat equivalent energy density (FHEED) is applied to describe the strain-dependent energy density of SWCNTs.