Table 10: Numerical comparison among [15, 31] CDM and DQM and the first three free frequencies of vibrations of DWCNTs are reported (for ).

Mode[31][15]CDMDQM

14 0.90971.051.02981.0299
2.36012.842.78952.7896
4.14815.185.10435.1045

18 0.57510.640.62760.6276
1.46481.751.72021.7203
2.61533.363.30363.3039

24 0.33400.360.35500.3549
0.83901.000.97700.9767
1.51621.941.90461.9046

28 0.24820.270.26140.2612
0.62030.730.72007.1905
1.12611.431.40741.4066