Effects of single vacancy defect position on the stability of carbon nanotubes

In this paper, the buckling behavior of fixed–fixed, both single- and multi- wall carbon nanotubes (CNTs) under axial compressive loads, are studied using analytical continuum theory and molecular dynamics (MD). An approach based on the tethering of atoms (applying a spring force), is used to apply the boundary conditions and extract the reaction forces during the MD simulation. The effects of the vacancy defect position on the CNT critical buckling load are studied at room temperature and at low temperature (1K). It is concluded that the defects at the ends of the CNT and close to the middle of the CNT significantly reduce the critical buckling load and strain of CNTs at 1K. At room temperature the influence of vacancy defects on the critical buckling load and strain appears to be small. The MD simulation results can prove to be useful for developing more accurate continuum descriptions of the CNT mechanics in future research.