Decay rates in nano tubes with consideration of surface elasticity

In the present paper we examine the Saint-Venant end effect in the nano tubes via a continuum mechanics with consideration of surface elasticity. The Saint-Venant end effect is quantitatively described by the decay rate. By analytically solving an axial-symmetric torsion in a circular cross-section tube configuration, we demonstrate that the decay rate decreases as the radius of the nano wire/tube decreases with consideration of the surface effect.