Wind loads on planar canopy roofs, Part 2: fluctuating pressure distributions and correlations

Fluctuating pressure distributions on planar canopy roofs are presented based 1:100 scale wind tunnel measurements obtained in a simulated suburban atmospheric boundary layer. For a range of roof pitch angles and wind directions, point and area-averaged pressure measurements were obtained with the worst loads experienced adjacent to lines of flow separation. For two particular roof pitches the cross correlations of area-averaged pressures were obtained and the covariance integration technique used to estimate the total fluctuating loads on the roof for 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 correlation of fluctuating pressures is accounted for in covariance integration. © 1994.