Molecular dynamics study of effects of sp3 interwall bridging and initial vacancy-related defects on mechanical properties of double-walled carbon nanotube

The mechanical properties of a double-walled carbon nanotube with some regular interwall sp(3) bonds (DWCNTSB) and a double-walled carbon nanotube (DWCNT) under uniaxial loading are investigated using the classical molecular dynamics simulations method. The interaction between atoms is modeled using the empirical Tersoff-Brenner potential coupled with the Lennard-Jones (L-J) potential. The sensitivity of the mechanical behavior with respect to the atom vacancy is also examined by prescribing various vacancy defects to the {5,5}&{10,10} DWCNTSBs and DWCNTs in the compression simulations. We get the Young's modulus of the ideal {5,5}&{10,10} DWCNT and the ideal {5,5}&{10,10} DWCNTSB,, under axial tension 1157.10 and 1028.3 GPa, respectively. We also obtain the critical buckling strains and critical buckling load of {5,5}&{10,10} DWCNTSB, and find that interwall sp(3) bonding of DWCNT can enhance load transfer and increase buckling resistance significantly. The computational results also shown that the vacancy-related defects lead to lower the buckling loads and buckling strains for both DWCNTSBs and DWCNTs. (C) 2008 Elsevier B.V. All rights reserved.