格构式塔架顺风向脉动风荷载空间相关性研究

Study on Spatial Correlation of Along-wind Fluctuating Wind Load of Lattice Tower

为了研究格构式塔架顺风向脉动风荷载的空间相关性,选取2段典型的格构式塔架节段模型,采用2个高频测力天平同步测力风洞试验技术,得到了不同水平距离和竖向距离情况下的模型基底剪力和弯矩的风荷载时程.在此基础上,通过数据处理分析,得到了各工况下塔架的顺风向风荷载相干函数.试验结果显示:格构式塔架顺风向风荷载相干函数与频率,水平距离和竖向距离等参数有关;结构顺风向风荷载相干函数与顺风向风速以及高层建筑等结构的风荷载相干函数存在一定差别.最后,采用最小二乘法,拟合得到了格构式塔架顺风向风荷载相干函数经验公式,试验结果与经验公式吻合较好,可为格构式塔架风荷载及风致响应计算提供有用的参考.

In order to study the spatial correlation of the along-wind fluctuating wind load of lattice tower, two segmental models of a typical lattice tower were selected, and two high frequency force balance technologies were employed. The time histories of the base shear and bending moment for the segmental models considering different horizontal and vertical distances between them were synchronously obtained in the wind tunnel test. Based on the extensive analysis of the obtained data, the coherence function formulas of the along-wind fluctuating wind load on the lattice tower model were obtained. The results show that the coherence functions of the along-wind fluctuating wind load on the lattice tower are related to the frequency, horizontal distance, and vertical distance. There is a certain deviation between the deduced coherence functions obtained by this experiment and the existing coherence functions of longitudinal wind speed or wind load of high-rise buildings. Finally, the least square method was used to fit an empirical formula of the coherence functions of the along-wind fluctuating wind load on the lattice tower. The experimental results are in good agreement with the empirical formula, which can provide a useful reference for the calculation of the wind load and wind-induced response of lattice towers.