Nonlinear elastic properties of carbon nanotubes subjected to large axial deformations

Nonlinear elastic properties of single-wall carbon nanotubes subjected to large-scale tensile deformation were investigated using the second-generation Brenner potential. The energy change of the nanotubes was found to be a cubic function of tensile strains. In contrast to values of in-plane stiffness C based on small strains reported previously in the literature, the present study showed that C is linearly dependent on axial tensile deformation. C is also affected by the chirality of the tubes to some extent when axial strains are large. Consequently, these tubes should be considered in the context of anisotropic elastic shell models in the event of employing continuum mechanics in the analysis of nanotubes.