摘要
在大跨屋盖表面局部区域,特别是迎风边缘区域和屋盖拐角区,风荷载会表现出明显的非高斯特性,如果仍采用高斯模型来描述,往往会产生较大误差。基于五种典型大跨度屋盖结构的风洞试验,对屋盖表面局部风压的高斯和非高斯特性进行了研究。首先通过对第三阶、第四阶矩统计量归纳分析,给出划分高斯区和非高斯区的标准并对大跨度屋盖进行分区;同时,运用基于k-s检验的曲线拟合方法也得到风压非高斯分区,利用分区结果,得到保证率为99.38%的峰值因子取值。将两种方法相对比,发现得出的分区结果相似:非高斯区域往往集中在来流前缘、后部尾流区及高点角区附近。此外,分析结果表明,对于大跨屋盖结构,应适当提高我国荷载规范中的峰值因子并按结构分区取值。
In the partial regions of a long span roof surface,especially,front and corner area,wind load always present distinct non-Gaussian characteristics.Larger error will be produced if Gaussian model is still adopted.On the basis of wind tunnel tests,a study was carried out on partition of Gaussian and non-Gaussian regions of wind pressure on the roof surface.Firstly,the third and fourth order statistical moments of fluctuating wind pressures were employed to obtain a description and measurement of the non-Gaussian feature.Furthermore,non-Gaussian regions on long span roofs were determined.In addition,the results of the divided non-Gaussian wind pressure regions were also gained by using curve fitting method based on k-s test.Afterwards,the peak factor of each measured point was given with a guarantee rate of 99.38 percent.Comparing the two methods above,it was found that the partition results almost coincide with each other.Non-Gaussian regions tended to be concentrated in the front,wake area and corner area near the high points.The analytic results showed that the value of peak factor regulated in Chinese load codes should be improved properly and its value should be taken according to partition of regions.
出处
《振动与冲击》
EI
CSCD
北大核心
2010年第7期9-15,共7页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(50678036)
关键词
大跨屋盖结构
风洞试验
脉动风压
非高斯特性
峰值因子
long-span roof structure
wind tunnel test
fluctuating wind pressure
non-Gaussian characteristics
peak factor
