THE NON-GAUSSIAN FEATURES OF WIND LOADINGON LARGE-SPAN ROOFS

摘要

This paper presents a study on the wind pressure field on large-span roofs, taking into account its non-Gaussianrnnature. Wind tunnel experiments for several shapes of large-span roofs were carried out in the boundary layerrnwind tunnel at Tongji University. Analysis presented in this paper is mainly base on the experimental data ofrnlarge-span flat roofs and saddle-shaped roofs. Experimental research in this paper has shown that the Gaussianrndistribution can not describe the wind pressure field correctly in some cases. In regions under separated flows,rnthe pressure probability density functions are skewed such that the probabilities for large negative fluctuationsrnare much higher than those of Gaussian processes. It has been proved that the sharp spikes commonly observedrnin separation region are mainly responsible for the non-Gaussian features. Experimental investigations in windrntunnels show that the non-Gaussian pressure fluctuations is concentrated on wind-sensitive areas such asrnbuilding edges or roof corners under the influence of cylindrical vortices or strong conical vortices. It isrnimportant to find a useful tool to characterize the non-Gaussian properties of the wind pressure field onrnlarge-span roofs. The marginal distributions and statistical moments of order higher than second will be used tornoutline the non-Gaussian nature of the pressure field. The pressure field on large-span roofs is classified intornzones of Gaussian and non-Gaussian pressure fluctuations by means of skewness and kurtosis coefficients. Thisrnwill be useful in modeling and generating pressure fluctuations.