Numerical simulation of buckling and postbuckling of single wall carbon nanotubes

Study of the critical buckling load as well as post-buckling behavior of single-walled nanotubes (SWNT) under various thermal conditions is the subject of this article. For finding critical buckling loads the clamped-free and simply supported conditions are considered and for post-buckling analysis the boundary conditions are assumed to be clamped. A space-frame model is here employed for the zigzag and armchair nanotubes with different chiralities and aspect ratios. In this approach، the linkage between carbon atoms is modeled as three dimensional elastic beam. By establishing a linkage between structural mechanics and molecular mechanics، the sectional property parameters of these beam members are obtained. The obtained results indicate that، as it is expected، by increasing the aspect ratio of the nanotubes as well as chirality، the critical buckling load decreases. Also، it is noticed that the post-buckling behavior of both armchair and zigzag nanotubes are quite similar. In addition، the effect of temperature on the critical buckling load is investigated. Due to the influence of temperature over the linkage length and force field constants it is shown that when the temperature increases a decline in the critical buckling loads is observed.