عنوان مقاله [English]
In this study, nonlinear vibrations of simply-supported pipes conveying fluid made of multilayer graphene reinforced composite materials have been investigated analytically and based on the Euler-Bernoulli beam theory. The constituent layers of the pipe wall thickness are considered to be made of polymer and graphene platelets and the reinforcing graphene platelets are varied by layers in the pipe wall thickness direction. Four different patterns for distribution of reinforcing graphene platelets along the pipe thickness direction, large deformations and Von-Karman nonlinear strain field are considered. The nonlinear governing equations are derived by Hamilton principle, they are converted to the ordinary differential equations by Galerkin method and then are solved analytically using the homotopy analysis method. The variations of the first nonlinear natural frequency of the system with respect to the variation of initial amplitude, fluid velocity, fluid density, pipe length and also time response of the nonlinear vibrations of the system are presented and analyzed for different distribution patterns V, X, O and U of the graphene platelets. The results show that the first nonlinear natural frequency of the system for all distribution patterns of graphene platelets is decreased by increase of pipe length, fluid velocity and density but, increasing the initial amplitude increases the first nonlinear natural frequency and also the distribution pattern V has the highest nonlinear frequency comparing with the other distribution patterns.