Buckling of multiwalled carbon nanotubes under axial compression

Buckling of single-walled and multiwalled carbon nanotubes (SWNTs and MWNTs, respectively) due to axial compressive loads has been studied by molecular mechanics simulations, and results compared with those from the analysis of equivalent continuum structures using Euler buckling theory and the finite element method. It is found that a MWNT of large aspect ratio (length/diameter) buckles as a column with axial strain at buckling given reasonably well by the Euler buckling theory applied to the equivalent continuum structure. However, a MWNT of low aspect ratio buckles in shell wall buckling mode with the axial strain at buckling corresponding to the highest axial strain at buckling of one of its constituent SWNTs. A finite element model has been developed that simulates van der Waals forces by truss elements connecting nodes on adjacent walls of a MWNT; the axial strain at buckling from it is close to that obtained from the MM simulations but the two sets of mode shapes are different.