WIND LOADS ON PLANAR CANOPY ROOFS .2. FLUCTUATING PRESSURE DISTRIBUTIONS AND CORRELATIONS

Fluctuating pressure distributions on planar canopy roofs are presente d based on 1:100 scale wind tunnel measurements obtained in a simulate d suburban atmospheric boundary layer. For a range of roof pitch angle s and wind directions, point and area-averaged pressure measurements w ere obtained with the worst loads experienced adjacent to lines of flo w separation. For two particular roof pitches the cross correlations o f area-averaged pressures were obtained and the covariance integration technique used to estimate the total fluctuating loads on the roof fo r a range of wind directions. Significant reductions in overall uplift and racking loads, were obtained using this method when compared with the traditional quasi-steady approach. This is because the partial co rrelation of fluctuating pressures is accounted for in covariance inte gration.