engleski

Wave properties of wind actions on structures

In this paper the wave properties of wind actions on structures analyzed on a single degree of freedom (SDOF) system are shown. The wave character of the action was examined by windows-wavelet analysis on several different measured data of wind actions. The constant and then the fluctuating action extracted from the wind force were analyzed by the wavelet transform. Fluctuating component of the wind action is represented by a harmonic function. The wavelet transform of wind action shows that the intensity of harmonic component decreases linearly with the number of cycles which implies that the resonance is not innate to wind action. All data of the wind action are obtained by measurements on SDOF oscillator. Time resolution varied from 0.01 to 0.00001 seconds. Significantly, the characteristics of wind action observed from the data on intensity of the averaging wind force are strongly connected with the length of the averaging wind force. The overall data of dynamic action show that the influence of wind is significantly higher for shorter periods of averaging. In this paper the term resonant spectra is used and the dynamic factor is based on them. The empirical relations for the value of the constant and the first harmonious component of the action are suggested. All results are compared with the classical spectra of the elastic force of SDOF system.

wavelet transformation; wind; resonant spectra; dynamic factor

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