Atomistic study of strain dependence of Poisson’s ratio of single-walled carbon nanotubes

The Poisson ratio of single-walled carbon nanotubes is calculated by the molecular-dynamics simulations. The result shows that the Poisson ratio depends on both the imposed strain and the chirality. Such dependences are addressed from the viewpoint of mechanics of the honeycomb lattice of nanotubes. It is shown that the changes of bond angles of the honeycomb lattice of nanotubes due to deformation tend to decrease the Poisson ratio. On the other hand, the increase of the chiral angle would tend to increase the Poisson ratio if it was not for deformation of the honeycomb lattice. In the simulation results, the Poisson ratio decreases with the increase of strain and chiral angle, which implies that the changes of bond angles in the honeycomb lattice dominantly determine the Poisson ratio of single-walled carbon nanotubes.