Axial and torsional buckling analysis of single- and multi-walled carbon nanotubes: finite element comparison between armchair and zigzag types

Abstract

The present work deals with the axial and torsional buckling analysis and design of carbon nanotubes (CNTs) by finite element. Computer-aided design, computer-aided engineering simulation, and finite element modeling are applied for the calculation of axial and torsional displacement and von Mises stresses. The smallest diameter of single-walled, double-walled, and multi-walled carbon nanotubes have been selected to survey armchair and zigzag types of CNTs. Nanotube diameters, covalent and van der Waals bonding, interlayer spacing, and chirality is considered in nanotubes construction based on actual dimensions. This paper illustrates that armchair-type nanotube is more resistant than zigzag-type against axial buckling for single-walled carbon nanotubes, whereas, in the case of torsional loading, zigzag-type show superior performance against buckling. By increasing the diameter and number of layers, due to van der Waals interaction, elastic buckling properties of nanotubes can be improved significantly. Data analysis for double-walled carbon nanotubes has shown that armchair-type is a better choice under combined loading, whereas, in the meantime, zigzag-type for triple-walled carbon nanotubes is preferred in the comparative analysis under combined loading. The results demonstrate the vital role of covalent intermolecular forces for single-walled nanotubes and van der Waals interlayer interactions for multi-walled nanotubes under buckling loading. The present study investigated the effect of covalent and van der Waals bonding for small diameter nanotubes.