Surface effect on buckling configuration of nanobeams containing internal flowing fluid: A nonlinear analysis

In this paper, the post-buckling behavior of supported nanobeams containing internal flowing fluid with two surface layers is studied based on a nonlinear theoretical model. The nonlinear governing equation, in which the surface effect and stretching-related nonlinearity are accounted for, is analytically solved for both clamped-clamped and pinned-pinned systems. The effects of nanobeam length, bulk thickness and several dimensionless parameters on the post-buckling behavior are analyzed. It is found that, the nanobeam with low flow velocity is stable at its original static equilibrium position and then undergoes a buckling instability at a critical flow velocity, which depends on the system parameters. When buckled, in all cases, the amplitude of the resultant buckling increases with the increasing flow velocity. Typically, the surface effect is explored by considering different nanobeam lengths and bulk thicknesses. The buckling amplitude is found to be length-dependent and thickness-dependent, showing that the effect of surface layers is considerably strong.