The Effect of Small Scale on Torsional Buckling of the Embedded Double- to Five- Walled Nanotubes Under Axial Loading and Thermal Field

This paper aims at investigating the torsional buckling behavior of the embedded multi-walled nanotubes (double- to five- walled) under combined loading based on the nonlocal continuum mechanics. The governing partial differential equations are derived according to Donnel shell model assumptions and Eringen elasticity theory. The effects of the number of layers of carbon nanotube, the existence of axial force, temperature change and the existence of the elastic medium on critical shear stress are studied. Results clearly reveal that at a fixed length, the carbon nanotube which has more layers can tolerate higher critical shear stress, although the existence of compressive axial force and/or temperature change at a high temperature environment decreases the load-bearing capacity of carbon nanotube. While the existence of elastic medium and/or tensile axial force increase the critical shear stress. It is also seen that with a rise in the number of half-wave, the effects of small-scale parameter on shear stress increase. The difference in predicting critical shear stress of multi-walled nanotubes between nonlocal and local continuum mechanics is investigated as well.