Study of torsional buckling behavior of carbon nanotubes using molecular dynamics simulations

Abstract

An accurate study of mechanical behavior of CNTs is vital to understand their response under mechanical loading in their applications. Much experimental and analytical work has been done to quantify the mechanical properties of CNTs over the past two decades. However, limited studies have been reported related to torsional behavior and estimation of shear modulus. The reported values of shear modulus of CNTs in the literature also shows considerable variations revealing the effects of the method used in the predictions. This paper reports the study carried out to investigate the effect of different parameters in estimating shear modulus and torsional buckling behavior of CNTs using molecular dynamic (MD) simulation method. MD simulator called largescale atomic/molecular massively parallel simulator (LAMMPS) is used in this regards. The effects of potential function (REBO and AIREBO) used to define atomic interaction and ratios of the CNT considered in simulation were studied with respect to Armchair and Zigzag CNTs with different diameters. The results of the studyrevealed that the effect of the CNT aspect ratio for estimating the shear modulus can be eliminated by using the CNTs with aspect ratio above 12. However, potential function use for the simulations has considerable impact on the results.