Strained Mechanical and Fracture Analyses of Armchair-Chiral-Zigzag-Based Carbon Nanotubes Using Molecular Dynamics Simulations.

Carbon nanotubes (CNTs) have emerged as one of the most capable and interesting materials in recent decades and have extraordinary mechanical properties (MPs) and resourceful applications in bioengineering and medicine. Equilibrium molecular dynamics simulations have been performed to investigate the structural and MPs of armchair, chiral, and semiconducting and metallic zigzag single-walled CNTs (SWCNTs) under varying temperature T (K) and compressive and tensile strains ±γ (%) with reactive bond-order potential. New results elaborate on the buckling and deformation mechanisms of the SWCNTs through deep analyses of density profiles, radial distribution functions, structural visualizations, and stress-strain interactions. Density profile and structural visualizations of SWCNTs provide the understanding of atomic arrangements and structural changes under varying ±γ (%) strains. The structure of SWCNT configurations is changed at varying ±γ (%) and T (K) and radial distribution functions present the appropriate peaks for buckling and deformation states. It has been shown that the mechanical responses of different chirality of the SWCNTs clarify the variations in tensile strength in terms of T (K) and chirality. Stress-strain analyses reveal that the metallic zigzag and armchair SWCNTs have superior tensile strength as compared to chiral ones, having the lowest tensile strength. Simulation results show that yield strength, ultimate tensile strength, and Young's modulus are higher for metallic zigzag and armchair SWCNTs at room T (K) and overall decrease with increasing T (K). However, the ultimate strain of semiconducting zigzag and armchair SWCNTs is higher as compared to other configurations, and it reflects the MPs of SWCNTs have to shed light on potential applications in nanotechnology and material sciences.