Auto-parametric sloshing in a rectangular aqueduct excited by wind vortex-induced vibration: experimental investigation and stability analysis

The vortex-induced vibration of the aqueduct girder may excite the parametric sloshing of the contained water which will have substantial impacts on the normal running and structural safety of the aqueduct bridge. This paper first conducts a wind-tunnel experiment to investigate the auto-parametric sloshing caused by wind vortex-induced vibration for an elastically-hung rectangular aqueduct with contained water. When the vortex excitation frequency is close to the natural frequency of the structure and approximately equal to twice the natural frequency of the fluid the vortex-induced resonance of the structure and the strong auto-parametric sloshing (internal resonance) of water successively occur in the test. The auto-parametric sloshing for the non-internal resonance case is also experimentally investigated. The contained water can be simplified as a rigid mass for the stability analysis of sloshing. The instability boundaries of sloshing and the corresponding wind speed regions are theoretically determined and compared with the experimental results