The Dynamic Response of Cross-Flow Vortex-Induced Vibration of Pipeline Bridge under External Linearly Sheared Flow

The pipeline bridge is a common structure in water transfer project. The external wind loads play an important role in the case of the flexible pipeline with large aspect ratio. In this paper, we investigate the dynamic response of cross-flow(CF) vortex-induced vibration(VIV) of pipeline bridge under external linearly sheared flow. Firstly, we apply the distributed van der Pol oscillator model to describe the location-dependent hydrodynamic loads on pipeline due to external sheared wind flow. And the dynamic equation of pipe with internal flow is deduced with the consideration of internal flow velocity, inner pressure and external tension. Secondly, the numerical analysis is conducted by central difference scheme. Finally, the lock-in response property and the effects of several factor, i.e. internal flow velocity, inner pressure, external tension and shear parameter, on the dynamic response are discussed in detailed. The results indicate that the multi-mode response always occurs in external sheared flow exhibits more complexity than single-mode response in external uniform flow. Among the above factors, the external tension has the greatest impact on dynamic response of pipeline bridge.