The effects of various distributions of vacancy defects on the mechanical properties in carbon nanotubes

In this paper, the influence of different arrangements of vacancy defects on the Young s and shear modules of armchair and zigzag single–walled carbon nanotubes (SWCNTs) is investigated. The variations of elastic modules with respect to the location of the defects, the separation distance between two defects, the number of defects and defect’s distributions are studied. SWCNTs are modeled using nonlinear spring elements to simulate covalent bonds and atomic mass of carbon atoms are attached to each node as a point mass. It is found that the presence of the first vacancy defect and its position has only significant effect on the shear module of armchair nanotubes. It is observed that the effect of gathered defects is more considerable than distributed defects, especially in the case of zigzag nanotubes. It can be deduced that generally shear module is more sensitive to the existence of the defects than Young s module.

Keywords:

Carbon nanotube , Mechanical properties , Vacancy defect , Defects distribution , Non–linear spring