Chirality dependence of mechanical properties of single-walled carbon nanotubes under axial tensile strain

The chiral dependence of the axial tensile strain versus stress characteristics for single-walled carbon nanotubes has been investigated by numerical simulation using a tight binding calculation and a first-principles density functional theory calculation. It is found that the tight binding calculation adopted is accurate. Both calculations show that nanotubes have a Young's modulus of 1.0 TPa and a maximum tensile strength of 0.10 TPa with no chiral dependence. However, the critical tensile strain for breaking has a chiral dependence. This is discussed from the viewpoint of the deformation of six-membered rings.