Mechanical properties of carbon nanotube under uniaxial tensile strain

Abstract

Based on the density functional theory with the generalized gradient approximation, we investigated the mechanical properties of single-walled carbon nanotubes (CNTs) in terms of the chiral angle and atomic vacancies under a uniaxial tensile strain. Young’s modulus monotonically decreases with increasing the chiral angle from zigzag to armchair. Furthermore, defects substantially decrease the modulus for all CNTs. The critical tension where the fracture starts also depends on the chirality and defect species. The chiral (10, 4)CNT exhibits the highest mechanical toughness against the tension of 109 nN at the 24% elongation, while the (7, 7)CNT with monovacancy exhibits the lowest toughness against the tension of 88 nN at 11% elongation.