Structural stability and energetics of single-walled carbon nanotubes under uniaxial strain

TL;DR

This study uses advanced simulations to analyze the mechanical stability, strength, and vibrational properties of a (10x10) single-walled carbon nanotube under uniaxial strain, revealing high strain tolerance and strain-sensitive vibrational frequencies.

Contribution

It introduces a parallel tight-binding molecular dynamics method to simulate large carbon nanotubes under strain, providing detailed mechanical and vibrational property data.

Findings

Carbon nanotube withstands up to 122% elongation and 93% compression.

Young's modulus is 0.311 TPa, tensile strength is 4.92 GPa.

Vibrational frequency in radial direction is 4.71x10^3 GHz and varies with strain.

Abstract

A (10x10) single-walled carbon nanotube consisting of 400 atoms with 20 layers is simulated under tensile loading using our developed O(N) parallel tight-binding molecular-dynamics algorithms. It is observed that the simulated carbon nanotube is able to carry the strain up to 122% of the relaxed tube length in elongation and up to 93% for compression. Young s modulus, tensile strength, and the Poisson ratio are calculated and the values found are 0.311 TPa, 4.92 GPa, and 0.287, respectively. The stress-strain curve is obtained. The elastic limit is observed at a strain rate of 0.09 while the breaking point is at 0.23. The frequency of vibration for the pristine (10x10) carbon nanotube in the radial direction is 4.71x10^3 GHz and it is sensitive to the strain rate.