Large span roof structures have been widely adopted for their good performance in multiple functionalities and innovative designs. However, because of their light weight, wind-resistant design is more urgent than earthquake-resistant design. And further, their long span geometry often results in a weak spatial correlation in pressure distributions and hence makes the estimation of wind loads a difficult task. Spectrum characteristics of wind pressures have been mentioned in several publications; however, there is still little discussion of cross-spectrum characteristics. In this paper, cross-spectra of fluctuating wind pressures on various dome-like roofs are investigated under a suburban terrain flow. By examining separately the root-coherence function and the phase function, approximation models of both functions are proposed in terms of the rise/span ratio based on certain simple but efficient assumptions. Once the two functions are simulated in good agreement with experimental results, the cross-spectra, or the co-coherence function, can be simulated by simply combining the root-coherence function and the phase function.
關聯:
Journal of the Chinese Institute of Engineers 41(7), p.579-589
