Anisotropic mechanical properties of S-graphene nanotubes: Influence of chirality, temperature, number of walls, and defects

Abstract

In this study, the mechanical properties of a novel two-dimensional (2D) graphene allotrope, S-graphene nanotubes (S-GNTs), are investigated for the first time using non-equilibrium molecular dynamics (NEMD) simulations. Key mechanical properties, including the fracture process, stress distribution, elastic modulus, toughness, ultimate stress, and fracture strain, are systematically examined. The influence of critical parameters such as length, radius, temperature, number of walls, and vacancy defects on these properties is analyzed. S-GNTs exhibit brittle behavior and anisotropic properties, with armchair fractures near boundaries due to stress concentration and zigzag fractures around the middle, reflecting chirality-dependent failure mechanisms. Temperature is the most influential factor, causing the largest and most pervasive degradation in mechanical properties due to increased thermal vibrations weakening atomic bonds. Radius has a greater influence on the mechanical properties of S-GNTs than length.