借助刚性模型风洞动态同步测压试验,对大跨度平屋盖表面脉动风压的非高斯统计特性进行了系统研究。首先,根据测点风压时程及其概率密度分布,对具有非高斯分布特性的屋盖风压局部区域做出判断;然后,通过风压的时空间相关性,结合中心极限定理讨论局部呈现非高斯特性的原因;最后,基于测点风压的第三、四阶矩统计量对风压的非高斯特性进行描述,给出划分高斯非高斯区域的标准,并在此基础上对平屋盖进行了分区,通过区域划分揭示了不同区域的脉动风压形成机理,也体现出一些大跨屋盖结构不同于低矮房屋的流场特性。通过匕述工作,增进了对大跨度屋盖表面风压分布特性的认识,为进一步探讨屋盖结构的抗风设计方法奠定了理论基础。
The non-Gaussian features of fluctuating wind pressures on long span roofs are systematically studied by using multi-channel measurement wind tunnel tests. Wind pressure sample time series and histograms are employed to identify the local regions in which the wind pressure fluctuations exhibit clear non-Gaussian nature. The cause for non-Gaussian features in separated regions is discussed by combining the analysis of spatial correlation of wind pressures and the central limit theorem. The third and fourth order statistical moments of fluctuating wind pressures are employed to obtain a description and measurement of the non-Gaussian feature, and to locate regions with non- Gaussian features in long span fiat roofs. Different wind fluctuating mechanisms, exhibiting different flow characteristics between long-span roofs and low-rise buildings, may be revealed from the division of roof regions.