Shear modulus and Poisson's ratio of single-walled carbon nanotubes: Numerical evaluation

The mechanical behaviour of non-chiral and chiral single-walled carbon nanotubes under torsional loading is studied. For this purpose, three-dimensional finite element modelling is used in order to evaluate the torsional rigidity and shear modulus. It is shown that the evolution of torsional rigidity as a function of nanotube diameter can be described by a unique function for non-chiral and chiral single-walled nanotubes. A comprehensive study to evaluate the Poisson's ratio of single-walled carbon nanotubes is also carried out. Two robust methodologies, one for evaluating the shear modulus from results of tensile, bending and torsion tests, and the other to assess Poisson's ratio from results of bending and torsion tests, are recommended.