In this study, an integrated framework based on density functional theory (DFT) and molecular dynamics (MD) simulations was employed to systematically investigate the existence possibility, the mechanical properties and fracture behavior of TH-graphyne nanotubes (TH-GyNTs) under uniaxial tensile loading. DFT calculations confirm the dynamical stability of two distinct configurations: the nanotube formed by rolling along the y direction (Nsingle bondI), which exhibits metallic behavior, and the nanotube rolled along the x direction (N-II), which displays semiconducting characteristics with a direct bandgap of 0.98 eV. MD simulations reveal pronounced mechanical anisotropy, such that loading along the x direction results in a higher ultimate tensile strength of approximately 135.83 GPa and a Young's modulus close to 0.4 TPa, whereas loading along the y direction allows for a significantly larger fracture strain of about 30.92%. To assess the influence of structural imperfections, vacancy defects were introduced over a concentration range of 0.5–2%, and the results indicate that exceeding the critical concentration of 0.5% leads to a substantial degradation in tensile strength. Furthermore, thermal analysis conducted over a temperature range from 1 to 800 K demonstrates a marked reduction in strength, ductility, and toughness at temperatures above 400 K, while the Young's modulus exhibits only a weak dependence on temperature. Overall, these findings provide initial structure–property insights and may serve as preliminary guidelines for assessing the potential of TH GyNTs in nanoscale mechanical systems.
