非高斯风场作用下桥梁抖振响应研究

Study on buffeting response of bridge under non-Gaussian wind field

  • 摘要: 为研究非高斯风场作用下桥梁结构的抖振响应特性,以太洪长江大桥为例,基于Hermite多项式模型,模拟了非高斯脉动风场时程,计算了不同平均风速下不同非高斯特性脉动风场的抖振响应。结果表明:非高斯风场作用下结构响应的幅值和均方根值均比高斯风场更大,非高斯特性越强,均方根值越大;随着平均风速的增加,风场峰度对结构响应均方根的影响逐渐明显。因此,对于非高斯风场,高斯过程假定低估了实际的响应情况。此外,不同非高斯特性脉动风场作用下,结构响应的偏度和峰度均趋近高斯过程的结果。

     

    Abstract: Taking Taihong Yangtze River Bridge as an example, the buffeting response of the bridge under non-Gaussian wind field is studied. Firstly, based on Hermite polynomial model, the time history of the non-Gaussian fluctuating wind field is simulated. Subsequently, the corresponding wind load time history is calculated, and the time domain analysis of the buffeting response of the bridge is carried out. Finally, by comparing the response results of fluctuating wind fields with different non-Gaussian characteristics under various mean wind speeds, the influence of non-Gaussian characteristics of wind field on the buffeting response of the bridge structure is discussed. The results show that the amplitude and root mean square (RMS) of the buffeting response under non-Gaussian wind field are larger than the counterparts under Gaussian wind field, and stronger non-Gaussian characteristics correspond to larger RMS. With the increase of mean wind speed, the influence of kurtosis of the wind field on the RMS of the response becomes more obvious. Therefore, the Gaussian process assumption underestimates the actual response of a non-Gaussian wind field. In addition, the skewness and kurtosis of the buffeting response under fluctuating wind field with different non-Gaussian characteristics are similar to the results of the Gaussian process.

     

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