Bridge Cable Force Identification Method Under the Phenomenon of Bimodal Fundamental Frequency in Vibration

An identification method of bridge cable force under the double peak phenomenon of fundamental frequency in vibration is studied in this paper. Accurate cable force identification is crucial for ensuring the safety and reliability of bridge structures in service. However, the phenomenon of double peak is often generated at the fundamental frequency in practical engineering, and traditional cable force identification methods based on cable single fundamental frequency component may not be effective in such cases. Based on the mechanism that the cable vibration in different directions is affected by different factors, this paper reveals the cause of the bimodal phenomenon for the first time, and proposes a new method for bridge cable force identification. The proposed method overcomes the difficulty of dense mode identification and considers the coupling effects of bending stiffness, sag and inclination on cable vibration, and is validated by using laboratory data and bridge monitoring data.