Macroscopic properties of carbon nanotubes from molecular-mechanics simulations

Results of molecular-mechanics simulations of axial and torsional deformations of a single wall carbon nanotube are used to find Young's modulus, the shear modulus, and the wall thickness of an equivalent continuum tube made of a linear elastic isotropic material. These values are used to compare the response of the continuum tube in bending and buckling with that obtained from the molecular mechanics simulations. It is found that the strain energy of bending deformation computed from the Euler-Bernoulli beam theory matches well with that obtained from the molecular-mechanics simulations. The molecular-mechanics predictions of the critical strains for axial buckling and shell wall buckling do not match well with those derived from the Euler buckling formula and the Donnell shell theory.