Tuning of Elastic Properties of Nanotubes by Imposing a Transverse Electric Field: Computational Approach

Abstract

In this study, we investigated the influence of a transverse electric field on the mechanical properties of carbon, boron nitride, and silicon carbide nanotubes based on density functional theory and continuum mechanics. To evaluate the Young’s modulus of the nanotubes, a compressive distribution loading was implemented in the direction perpendicular to the longitudinal axis of the nanotubes in the presence and absence of an electric field. According to the obtained results from the geometry of the deformed nanotubes, an elliptical function was used to estimate the overall deformation. Based on the Green strain theory, the displacement of each particle is defined by the conversion matrix to transform the initial circular shape of the nanotubes to the final elliptical shape. The classical continuum theory was employed to estimate the relationship between strain energy and strain field of the nanotubes. An evolutionary genetic algorithm was used to achieve an accurate estimation of the fitting of the energy function versus strain based on the elasticity theory. In addition, the effect of the electric field on the electronic and mechanical properties of the nanotubes was investigated. The numerical results revealed that the nanotubes exposed to the electric field have more effective stiffness in comparison to the similar case in the off-field condition.