TITLE:
Wavelet-Based Nonstationary Wind Speed Model in Dongting Lake Cable-Stayed Bridge
AUTHORS:
Xuhui He, Jun Fang, Andrew Scanlon, Zhengqing Chen
KEYWORDS:
Time-Varying Mean Wind Speed, Nonstationary Wind Speed Model, Cable-Stayed Bridge, Wavelet Transform (WT), Wind Characteristic, Wind-Rain-Induced Vibration
JOURNAL NAME:
Engineering,
Vol.2 No.11,
November
26,
2010
ABSTRACT: The wind-rain induced vibration phenomena in the Dongting Lake Bridge (DLB) can be observed every year, and the field measurements of wind speed data of the bridge are usually nonstationary. Nonstationary wind speed can be decomposed into a deterministic time-varying mean wind speed and a zero-mean stationary fluctuating wind speed component. By using wavelet transform (WT), the time-varying mean wind speed is extracted and a nonstationary wind speed model is proposed in this paper. The wind characteristics of turbulence intensity, integral scale and probability distribution of the bridge are calculated from the typical wind samples recorded by the two anemometers installed on the DLB using the proposed nonstationary wind speed model based on WT. The calculated results are compared with those calculated by the empirical mode decomposition (EMD) and traditional approaches. The compared results indicate that the wavelet-based nonstationary wind speed model is more reasonable and appropriate than the EMD-based nonstationary and traditional stationary models for characterizing wind speed in analysis of wind-rain-induced vibration of cables.