Coupled vibration characteristics of a rotating composite thin-walled beam subjected to aerodynamic force in hygrothermal environment

The present paper aims to deal with the combined influences of hygrothermal environment, aerodynamic force and design parameters on the bending-bending coupled vibration of the rotating composite thin-walled beam. Based on the Hamilton's principle, the governing differential equations of the bending-bending coupled vibration are obtained for the rotating composite thin-walled beam under aerodynamic force and hygrothermal environment. In order to obtain the vibration characteristics of the rotating composite thin-walled beam, the coupled governing equations are transformed into a state equation as matrix-vector form via the Galerkin method. Finally, the influences of the bending-bending coupling and some parameters such as rotating speed, setting angle, pitch angle, hygrothermal factors and aerodynamic effect on the coupled vibration characteristics are analyzed. Results show that for the rotating composite thin-walled beam, which is subjected to aerodynamic force in hygrothermal environment, the flapwise bending and edgewise bending vibrations are not independent, but usually affect each other. (C) 2018 Elsevier Ltd. All rights reserved.