Monitoring, intelligent perception, and early warning of vortex‐induced vibration of suspension bridge
Danhui Dan, Hou‐Jin Li
Abstract
Vortex-induced vibrations (VIVs) are a serious problem in suspension bridges and other long-span bridges during their service periods. It can cause excessive amplitudes of the structure under low wind speeds, not only affecting driving comfort and safety but also increasing the risk of fatigue failure. Previous research on the identification and evaluation of bridge VIV events during their service periods was based on offline batch processing and analyses of monitoring data, which cannot realize real-time perception, calculation, and early warning online. This paper proposes an intelligent monitoring and warning method for VIVs of suspension bridges based on the recursive Hilbert transform according to the vibration characteristics of single-mode sinusoidal-like vibrations of engineering structures during VIVs. First, the real-time acceleration integral algorithm is used to realize the real-time calculation from the acceleration monitoring data to the dynamic displacement of the stiffening beam. Then, the recursive Hilbert transform is used to obtain real-time analytical signals of the structural displacement during VIVs. Based on its single-mode near-circular trajectory characteristic, the VIV index and the real-time analysis method are proposed to characterize the development trend of VIV events. This online extraction algorithm can realize the first warning and whole-process tracking and perception of VIV events. Furthermore, this paper presents a real-time online identification method for key motion parameters such as the instantaneous frequency, phase, and amplitude of the structure during VIV, laying the foundation for the real-time monitoring of the entire VIV process and further evaluation and management decision making. The accuracy, reliability, and engineering feasibility of the proposed method are verified by performing numerical simulations and monitoring VIV data of a real bridge.