Vibration and instability analysis of visco-DWCNTs conveying fluid based on surface sinsuidal couple stress theory

چکیده مقاله

In this paper, vibration and instability analysis of embedded double-walled carbon nanotubes (DWCNTs) conveying fluid under 2D magnetic fields is studied. The sinusoidal shear deformation beam theory (SSDBT) along with modified couple stress theory are used for modeling of DWCNTs. The material properties of DWCNTs are assumed viscoelastic using Kelvin–Voigt model and the elastic medium is simulated by visco-Pasternak foundation. The effects of surface stress are considered based on Gurtin–Murdoch elasticity theory. Hamilton's principle is applied for calculating of motion equations. The differential quadrature method (DQM) is applied for obtaining the frequency and critical fluid velocity of system. The detailed parametric study is conducted, focusing on the combined effects of the nonlocal parameter, magnetic field, visco- Pasternak foundation, surface stress and fluid velocity on the vibration and instability of DWCNTs. The results depict that the surface stress effects on the frequency of visco- DWCNTs are very significant.