vibration analysis of double bonded composite pipe reinforced by bnnts conveying oil

In the present research, nonlinear vibration in a coupled system of boron-nitride nano-tube reinforced composite (bnntrc) oil pipes is studied. single-walled boron-nitride nano-tubes (swbnnts) are arranged in a longitudinal direction inside poly-vinylidene fluoride (pvdf) matrix. damping and shearing effects of surrounded medium are taken into account by visco-pasternak model. based on piezoelectric fiber reinforced composite (pfrc) theory, properties of smart coupled bnntrc oil pipes are obtained. the equations of motion as well as the boundary conditions are derived using hamilton’s principle. the effects of various parameters such as volume fraction and orientation angle of fibers, viscosity and density of fluid on stability of coupled bnntrc oil pipes are investigated. results indicate that stability of smart composite system is strongly dependent on angle orientation and volume percent of bnnts. results of this investigation can be used in oil refineries.