Atomistic insights into the fracture mechanisms of Stone–Wales-defected CNTs under transversely isotropic loading

Abstract

The fracture mechanics and transversely isotropic elastic characteristics of carbon nanotubes (CNTs) incorporating the Stone–Wales (SW) defect were investigated using the molecular dynamics simulation with Adaptive Intermolecular Reactive Empirical Bond Order force fields. To accomplish this, the CNTs were subjected to uniaxial tension, torsion, in-plane shear, and in-plane biaxial tension. The effects of chirality and defect orientations throughout the length and circumference of CNTs were extensively evaluated. The bonds failure mechanism was used to elaborate the fracture process of both pristine and SW-defected CNTs under each loading condition. Our analysis demonstrated that the elastic constants, except for the longitudinal shear modulus, decrease very little with SW defects, and the orientation of SW defects negligibly alters the elastic properties of CNTs, but it affects the critical stress and strain. This is due to the difference in the failure mechanism. The plane-strain bulk and in-plane shear moduli and Young's modulus are reduced by about 1–4% and the shear moduli by 28% upon incorporating SW defects in the CNTs. Due to the widespread utilization of CNTs in a multitude of applications, including mechanical and electronic devices, energy storage systems, advanced polymer nanocomposites, and so on, our study emphasizes the crucial role of SW defects in influencing the elastic characteristics and fracture behavior of CNTs. © 2023, The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.