A Study on the Fluctuating Pressure Correlation of a Cantilevered Elliptic Annular Roof Structure

A wind tunnel test on a large-span cantilevered elliptical annular roof was carried out. The time series of wind pressures were tested simultaneously on the upper and lower surfaces of a roof structure rigid model, that was exposed to open and suburban boundary layer air flows in various wind directions. The spatial correlation characteristics of fluctuating pressures on the roof structure were analyzed. Both the analyzing results of the correlation coefficient in time domain and the coherence function in frequency domain indicated that the correlation structure of the fluctuating pressure of a large-span roof is sensitive to the location of the investigated taps, the roof geometry, the wind direction, and the inflow turbulence. Therefore, the simulation methodology, using a single coherence function, based on the spatial interval of two taps, ignoring the geometry characteristics and the particular tap locations on the roof, a method commonly used in wind load simulations for high-rise and flat roof structures, is shown to not be appropriate for large-span cantilevered roof structures. This quasi-steady approach cannot be employed to evaluate large-span roof structures.