Statistical analysis of wind loadings and responses of a transmission tower structure.

摘要

The nature of this research is to study the statistical properties of the wind and associated structural response data for a transmission line tower. These data were collected by the Bonneville Power Administration in Oregon. The transmission tower structure is considered as the structural system. Wind speeds and the loads from the conductors are considered as the loadings on the structural system. Members leg stresses are considered as the responses of the structural system.; Basic statistical properties are first obtained for the wind speed, conductor load, and member leg stress time histories. Autocorrelation functions of these time histories are then calculated. Finally, the cross correlation functions relating the loadings and responses time histories are calculated.; The behavior of the structural system is next described in terms of the frequency response functions in the frequency domain. In the frequency domain analysis, power spectra of the loading and response time histories are calculated. The cross spectra relating the loadings and the responses are also calculated. Based on power spectra and the cross spectra, the frequency response functions may be estimated for the structural system.; The computations of the frequency response functions are achieved in two phases. First, the various combinations of the frequency response functions relating a single loading and a response are obtained. Finally, the various combinations of the frequency response functions relating two loadings with a response are obtained. The Wiener-Hopf equations are used in multiple loading case. Comparison of results for the two cases mentioned above are made. Conclusions and recommendations are given.; Finally, the wind speed time histories are modeled using the methodology advanced by Box and Jenkins. The modeled time series are used to obtain the model power spectra. The model power spectra are compared with the estimated power spectra.