Wake-induced Vibration of Two Types of Hangers of Suspension Bridge Based on Three Dimensional Aeroelastic Test Model and Its Mitigation
Long-span suspension bridge hangers are prone to large amplitude vibration under wind load because of their low frequency and low damping.In order to compare the difference of wake-induced vibration characteristics between parallel wire strand(PWS)and wire rope(WR)hangers,a systematic experimental investigation was carried out on the four-cable hangers based on the Lingdingyang Bridge.First,three-dimensional aeroelastic models of two types of hangers were designed and manufactured,and the dynamic parameters of the test models were identified.Then,wind tunnel tests on the aeroelastic test model were conducted to obtain the wind-induced vibration of the two types of four-cable hangers.The influence of wind velocity and wind attack angles on the wake-induced vibration of two types of four-cable hangers was investigated.Finally,several different countermeasures to reduce the wind-induced vibration of the hangers(including spacers,tuned mass damper,cross-ties and increasing damping ratio)were performed.The results show that the most disadvantageous attack angle for wake-induced vibration of both hangers is 75°,and cable collision phenomenon is observed at several working conditions.The first-order vibration of hangers are mainly occurred,with a clockwise elliptical trajectory.Compared with PWS hangers,the range of wind attack angles of WR hangers with wake-induced vibration are larger.The wake-induced vibration of the hangers can be effectively suppressed by adding three equally spaced spacers.On this basis,wind-induced vibration can be effectively suppressed by the countermeasure of adding cross-ties.
bridge engineeringsuspension bridge hangerswind tunnel testswake-induced vi-brationthree-dimensional aeroelastic modelsvibration control
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