Nonlinear extension of single-walled carbon nanotubes analyzed by a continuum model based on a higher-order cauchy-born rule

摘要

The mechanical properties and strain energy of single-walled carbon nanotubes (SWCNTs) under axial extension is investigated by a finite deformation continuum model derived from the interatomic potential of carbon. The proposed constitutive model is developed based on the so-called higher-order Cauchy-Born rule, which is an extension of its classic counterpart for crystal membranes. It is found that the strain energy obtained under finite deformation agrees well with that of atomistic calculations. Furthermore, the influence of the radial and inner displacement relaxations on the strain energy and the tangential elastic moduli are also explored for axially stretched and otherwise unconstrained SWCNTs.