Resonance Dynamics And Energy Transfer Of The Cable-Stayed Beam

As an important component of the cable-stayed bridge, the cable can decrease the moment and measure of the deck, and improve the spanning capability of the bridge. However, due to its low damping, low quality and large flexibility, the cable causes the large amplitude vibration when it is induced, which has adverse impact on the bridge. In past, the dynamics of the pure cable was focused on, whereas the nonlinear interaction between the cable and the tower/girder was neglected. To comprehensively understand the large vibration mechanism of the cable, this thesis establishes the refined model of cable-stayed beam. The Galerkin method and multi-scale method are applied to obtain the nonlinear response. Moreover, the experiments are performed to valid the numerical result. The contents of this thesis in detail are as following:1. Based on the continuum conditions between the beam and the cable, the governing equations of cable-stayed beam are derived by the Hamilton principle and condensation. Then the condensed equations and the natural frequency equations and modes are obtained. And the parameter analysis and the characteristics of mode shape are discussed.2. The resonance responses are deduced by Galerkin discrete method and multi-scale method. The two-to-one and one-to-one internal resonances between different modes are highlighted. Then the steady solution is discussed by frequency/force-amplitude curves. Moreover, using the Floquet theory and the shooting method, the dynamic stability is investigated.3. Experimental study on cable-stayed beam is performed. The natural frequencies and dynamic response of the structure are tested and applied to compare with the theoretical results.4. The mode energy and component energy are defined, and they are applied to investigate the energy transfer and distribution in the cable-stayed beam. Moreover, the energy transfer mechanism is discussed.