Influence of inversion energy on elastic properties of single-walled carbon nanotubes

An analytical molecular mechanics model, in which the inversion energy is considered besides the bond stretch and bond angle variation energies, is developed for the prediction of mechanical properties of single-walled carbon nanotubes (CNTs). The closed-form expressions for the surface Young's modulus and the Poisson's ratio of achiral and chiral carbon nanotubes are obtained based on the developed model. The present results show the influence of the tube diameter and the inversion energy on the mechanical properties of carbon nanotubes is significant when the tube diameter is small. With increasing the tube diameter, the surface Young's modulus and the Poisson's ratio approach, respectively, those of a graphite sheet and the influence of the inversion energy becomes weak gradually.