ABSTRACT
The mechanical properties of oxygen-functionalized single-walled carbon nanotubes (CNTs) are studied herein by molecular dynamics (MD) simulations. An analysis of the random distribution of oxygen atoms on CNTs of various functionalization percentages is presented in this study. The influences of the nanotube length, diameter, and the percentage of functionalization on longitudinal Young's modulus, failure stress, strain, and toughness are investigated. The results show that for both zigzag and armchair chiralities, Young's modulus decreases by increasing the nanotube diameter and length-to-diameter ratio. Also, the values of all studied properties including Young's modulus, stress, strain, and toughness are reduced by increasing the functionalization percentage until the nanotube reaches failure. Moreover, the reason for the alteration of the mechanical properties of nanotubes and the behavior of the stress-strain diagram are discussed.
ABSTRACT
This paper aims to study the mechanical properties of the multi-layered graphyne and other members of the graphyne family under the uniaxial tensile loading. For this purpose, molecular dynamics simulations are used. The effects of the size and number of layers on the fracture and elastic properties are studied. It is shown that Young's modulus of the zigzag multi-layered graphyne is slightly larger than armchair one. Comparing the stress-strain curves of the multi-layered graphynes with different number of layers, it is observed that the fracture stress and strain of the nanosheets are inversely related to the number of layers. Investigating the influence of the number of acetylene linkage in the structure of the graphyne-n family on their mechanical properties, it is shown increasing the number of triple bonds leads to weakening the fracture stress and Young's modulus of the nanosheet.
