Investigation of the mechanical properties of carbon nanotubes, under the influence of imperfections

Abstract

A carbon nanotube is a hollow cylinder, which is made of carbon atoms in the hexagonal lattice, which is made by rolling up the grahene sheet in the specific chiral vector direction. This cylindrical structure has outstanding mechanical, electrical thermal properties. Several attempts have been done to obtain the mechanical properties of CNTs in terms of Young’s modulus, shear modulus, tensile strength etc. The finite element method has been used to obtain the Young’s modulus of variety SWCNTs in this study. Furthermore, the imperfection (carbon vacancy) in the structure of SWCNT has been investigated on these models. Imperfection is one of the issues occurred in the producing of carbon structures such as graphene and carbon nanotubes and has a huge influence on mechanical properties of CNTs. This study consists of 68 different carbon nanotube models in three different types that are zigzag models from (3, 0) to (17, 0), armchairs from (2, 2) to (10, 10) and chiral models between (2, 2) and (10, 10). The imperfection percentages that investigated in this study are 5%, 10% and 15%. The results show that all models lose 34%, 56% and 90% of their tensile strength when they lost 5%, 10% and 15% of their carbon atoms from their structures (imperfection).