The effects of the presence of a single Stone-Wales defect or a single vacancy defect on the elastic properties and the fracture pattern of a single-walled carbon nanotube were investigated using molecular dynamics simulations. Three samples of single-walled carbon nanotube were considered: one each of chiral, armchair and zig-zag type. In all three samples, significant changes were observed compared to a defect-free tube. A defective chiral (10,6) tube showed more stability under stretched condition compared to the armchair (7,7) or the zig-zag (10,0) tube as revealed from the energy differences between defective and defect-free tubes at different stages of deformation. Fluctuation of energy differences for higher strain values for the same defect orientation was observed to be most pronounced in the case of a zig-zag tube and hence showed a less stable configuration than the other two tubes. The fracture pattern in each case was modeled and showed that defects play a major role in the breaking mechanism of a single-walled carbon nanotube. Also the differences in fracture modes of chiral and achiral tubes prove the dependence of their mechanical behavior on chirality.

Molecular Dynamics Simulation of Elastic Properties and Fracture Behavior of Single Wall Carbon Nanotubes with Vacancy and Stone-Wales Defect. K.Talukdar, A.K.Mitra: Advanced Composite Materials, 2011, 20[1], 29-38