摘要
为研究风场特性及矩形断面长宽比等因素对矩形高层建筑脉动风荷载功率谱特性的影响,以矩形断面(宽厚比B/D=2∶1,1∶2)为例,采用刚性模型测压风洞试验的方法,测得了边界层中矩形模型的脉动风荷载时程.参考日本建筑设计建议(AIJ)给出的横风向脉动风荷载谱模型,对试验结果进行拟合,给出了一个简化的矩形高层建筑横风向脉动风荷载功率谱函数表达式.试验结果表明,顺风向脉动风荷载主要由纵向紊流引起,其功率谱密度函数特征与来流紊流基本一致;横风向脉动风荷载的形成机理较为复杂,矩形断面侧边存在复杂的分离流动及再附现象,但其无量纲功率谱密度沿高度基本一致;斯托哈尔数沿高度方向变化较小,当宽厚比分别为2∶1和1∶2时,斯托哈尔数分别约为0.128和0.069 7.
In order to study the effects of wind field characteristics and side ratio of rectangular section on the spectral characteristics of fluctuating wind loads for rectangular high-rise buildings, the pressure fluctuations on a stationary rigid model with cross configurations of 1 ： 2 and 2：1 were measured by wind tunnel test for synchronous pressure measurement in simulated atmospheric boundary layer. Referring to the spectral model given by the Architectural Institute of Japan （AIJ）, a simplified spectral expression of fluctuating across-wind loading of rectangular high-rise building was proposed by fitting the measured results. The experimental results show that the fluctuating along-wind load is mainly caused by longitudinal turbulence, and the spectrum of fluctuating along-wind load is consistent with those of incident turbulence. The formation mechanism of fluctuating across-wind loads is more complex, and there is vortex shedding, separation or reattachment on the sides of the rectangular prism. The dimensionless power spectral density and the Strouhal numbers are almost constant along the height. The values of Strouhal number are 0. 128 and 0. 069 7 respectively for the side ratios of 2：1 and 1： 2.
出处
《西南交通大学学报》
EI
CSCD
北大核心
2017年第1期83-90,共8页
Journal of Southwest Jiaotong University
基金
国家自然科学基金资助项目(51278433
51478402)
关键词
矩形高层建筑
风洞试验
脉动风荷载
功率谱特性
数学模型
high-rise building
wind tunnel test
fluctuating wind loads
spectral characteristic
mathematical model
