Elastic properties of single-walled carbon nanotubes in transverse directions

The elastic deformation of single-walled carbon nanotubes under hydrostatic pressure has been modeled using the molecular structural mechanics method. The computational results indicate that the radial direction elastic modulus deceases with the increase in tube diameter. The circumferential direction elastic modulus is insensitive to tube diameter, and roughly equal to the axial direction modulus. The hydrostatic pressure for tube buckling also deceases with increasing tube diameter and is in the range of 1.5--11 GPa for single-walled carbon nanotubes with diameters of 0.6--2.0 nm; this prediction is in good agreement with existing experimental results. The tube chirality has minor effect on the radial modulus and buckling strength.