On the Mechanical Properties of Chiral Carbon Nanotubes

Carbon nanotubes (CNTs) are specific structures with valuable characteristics. In general, the structure of each nanotube is defined by a unique chiral vector. In this paper, different structures of short single-walled CNTs are simulated and their mechanical properties are determined using finite element method. For this aim, a simple algorithm is presented which is able to model the geometry of single-walled CNTs with any desired structure based on nano-scale continuum mechanics approach. By changing the chiral angle from 0 to 30 degree for constant length to radius ratio, the effect of nanotube chirality on its mechanical properties is evaluated. It is observed that the tensile modulus of CNTs changes between 0.93-1.02 TPa for different structures, and it can be higher for chiral structures than zigzag and armchair ones. Also, for different chiral angles, the bending modulus changes between 0.76-0.82 TPa, while the torsional modulus varies in the range of 0.283-0.301TPa.