结构-尾流振子耦合模型参数识别及桥梁涡激振动预测

为准确预测桥梁涡激振动特征,基于结构-尾流振子耦合模型涡激振动预测方法,分析其动力方程及近似解,针对目前结构-尾流振子耦合模型中较难确定的模型参数(质量参数M、流场“stall”效应参数γ、结构对尾流作用的耦合项参数A和范德珀尔参数ε),提出了基于涡激振动风速~振幅曲线的模型参数识别方法。开展某主梁节段模型风洞试验,依据其实测涡振曲线,采用该方法识别模型参数,并预测不同阻尼比的桥梁涡激振动特征。结果表明:近似解精度与ε相关,ε越小,精度越高;ε越小,提出的模型参数识别方法越能准确识别模型参数;基于风洞试验实测涡激振动风速~振幅曲线识别的结构-尾流振子耦合模型可有效地预测桥梁涡激振动特征。

Parameter Identification and Bridge Vortex-Induced Vibration Prediction Based on Structure-Wake Oscillator Coupling Model

In this paper,a vortex-induced vibration prediction method based on structure-wake oscillator coupling model is used to analyze the dynamic equations and approximate solutions,aiming to accurately predict the property of the vortex-induced vibrations on bridge.At present,it is still difficult to determine the parameters of the structure-wake oscillator coupling model(including the mass M,flow field“stall”effectγ,coupling force A and van der Pol parameterε),a model parameter identification method based on the wind speed-amplitude curve is proposed.The segmental wind tunnel test was carried out.Together with the measured vortex-induced vibration curves,the model parameters were identified by the proposed method,and the properties of the vortex-induced vibrations on the bridge with different damping ratios were predicted.The results show that the accuracy of appropriate solutions is correlated withε,namely the smaller theε,the higher the accuracy.Smallerεindicates higher prediction accuracy of the model parameters using the proposed method.The structure-wake oscillator coupling model based on the measured wind speed-amplitude curves from the wind tunnel test can effectively predict the property of vortex-induced vibrations of bridge.