Ranjbar - Department of Mechanical Engineering ,University of Kashan
Ghorbanpour - Department of Mechanical Engineering ,University of Kashan

The Growth and stability characteristics of double-walled carbon nanotubes (DWCNTs) are studied. The intertube interaction energy is calculated using the van der Waals interatomic potential, the effects of surrounding elastic medium on outer tube and the Van Der Waals forces between two adjacent tubes are taken into account. Expressive equations are derived for the critical axial force of inner and outer tube of DWCNT, this study shows that the critical axial force of inner tube of DWCNT decreases with the increasing axial half sine wavenumbers (m) and increases with the increasing circumferential sine wavenumbers(n), hrthermore critical axial force of outer tube of DWCNT increases as the axial half sine wavenumbers (m) increase and decreases to the minimum value as the circumferential sine wavenumbers(n) increase to 21 wavenumbers and. increases with addition a1 circumferential sine wavenumbers(n)