Size-dependent buckling analysis of different chirality SWCNT under combined axial and radial loading based on orthotropic model

In the present study, the size-dependent buckling behavior of carbon nanotubes (CNTs) is investigated on the basis of orthotropic shell model. Due to the nature of carbon nanotubes, their properties differ in various directions; therefore, they must be treated as anisotropic shells. Moreover, due to the small dimensions of CNTs, material length scale parameter must be included to predict the mechanical behavior of CNTs more accurately; accordingly this study is carried out on the basis of the new modified couple stress theory. CNT buckling affects the stability of nanocomposites and nanoactuators and small dimensions and different properties affect the CNT stability. In this article, using minimum potential energy principle, the equilibrium equations and boundary conditions are derived. Then, the buckling response of simply supported CNTs under combined loading is studied and the critical buckling load of the orthotropic CNT is calculated for various structural and geometrical conditions. Finally, the molecular dynamics (MD) simulation is performed to investigate the axial buckling behaviour of defective CNTs. (paper)