| 方形结构风荷载Jensen数效应研究 |
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| 引用本文： | 白 桦,叶 茂,杨世全,刘健新. 方形结构风荷载Jensen数效应研究[J]. 建筑科学与工程学报, 2023, 0(2): 105-115. DOI: 10.19815/j.jace.2021.09045 |
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| 作者姓名： | 白 桦 叶 茂 杨世全 刘健新 |
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| 作者单位： | (长安大学 公路学院,陕西 西安 710064) |
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| 摘 要： | 为了解试验模拟的地表粗糙度偏差对方形结构风荷载的影响,在风洞中模拟不同缩尺比的A、B两类粗糙度指数风场,研究Jensen数分别为1 200、6 000时结构风荷载的Jensen数效应。结果表明:Jensen数变化对平均风荷载影响很小,对脉动风荷载影响较大; Jensen数由6 000减小到1 200时,顺风向、横风向、扭矩脉动风荷载增大幅度约为200%～250%; Jensen数减小会使风荷载功率谱低频段能量呈小幅增大趋势,高频段能量呈小幅减小趋势; 当来流与方形结构的直线边存在一定夹角时,Jensen数变化对各类型风荷载相关性影响变小; Jensen数增大会使各层间顺风向、横风向与扭矩风荷载相关性减小; Jensen数由1 200增大为6 000时,对扭矩风荷载相关性影响最大,降幅为63%,横风向风荷载相关性最大降幅为40%,顺风向风荷载相关性最大降幅为15%; 增大Jensen数会使顺风向风荷载相干函数与Davenport指数衰减形式吻合的频率范围增大,高频部分的竖向相干函数减小; 横风向风荷载与扭矩风荷载竖向相干函数更符合Davenport指数衰减形式。
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| 关 键 词： | 方形结构 风洞试验 Jensen数 风荷载 相关性 |
Study on Jensen number effect of wind load on square structure |
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| BAI Hua,YE Mao,YANG Shiquan,LIU Jianxin. Study on Jensen number effect of wind load on square structure[J]. Journal of Architecture and Civil Engineering, 2023, 0(2): 105-115. DOI: 10.19815/j.jace.2021.09045 |
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| Authors: | BAI Hua YE Mao YANG Shiquan LIU Jianxin |
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| Affiliation: | (School of Highway, Chang'an University, Xi'an 710064, Shaanxi, China) |
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| Abstract: | In order to understand the effect of the deviation of surface roughness on square structure wind load, two kinds of roughness index wind fields of A and B with different scale ratios were simulated in wind tunnel, and the Jensen number effect on the structural wind load when the Jensen number was 1 200 and 6 000 respectively was studied. The results show that the variation of the Jensen number has little influence on the mean wind load, while it has a greater influence on the fluctuating wind load. When the Jensen number is reduced from 6 000 to 1 200, the increase range of along-wind, cross-wind and torsional wind load is 200%-250%. With the decrease of the Jensen number, the energy of the wind load power spectrum increases slightly in low frequency, and decreases slightly in high frequency. The influence of the change of the Jensen number on the various types of wind load is relatively small, when there is an intersection angle between the flow direction and the straight edge of the square structure. The increase of Jensen number will reduce the correlation between along-wind direction, cross-wind direction and torsional wind load. The increase of the Jensen number from 1 200 to 6 000 imposes great effects on torsional wind load, which has a decrease of 63%, while the maximum decrease in across-wind load correlation is 40% and the maximum decrease in along-wind load is 15%. With the increase of the Jensen number, the frequency range of the along-wind load coherence function with the Davenport exponential attenuation increases, while vertical coherence function decreases in high frequency part.The vertical coherence function of cross-wind load and torsional wind load is more consistent with the Davenport exponential attenuation form. |
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| Keywords: | square structure wind tunnel test Jensen number wind load correlation |
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