Since single-walled carbon nanotube (SWCNT) and multi-walled
carbon nanotube (MWCNT) are found by Iijima (1991, 1993), these
nanomaterials have stimulated extensive interest in the material
research communities in the past decades. It has been found that
carbon nanotubes possess many interesting and exceptional
mechanical and electronic properties (Ruoff et al., 2003; Popov,
2004). Therefore, it is expected that they can be used as
promising materials for applications in nanoengineering. In
order to make good use of these nanomaterials, it is important
to have a good knowledge of their mechanical properties.
Experimentally, Tracy et al. (1996) estimated that the Young’s
modulus of 11 MWCNTs vary from 0.4TPa to 4.15TPa with an average
of 1.8TPa by measuring the amplitude of their intrinsic thermal
vibrations, and it is concluded that carbon nanotubes appear to
be much stiffer than their graphite counterpart. Based on the
similar experiment method, Krishnan et al. (1998) reported that
the Young’s modulus is in