大跨越钢管混凝土输电塔顺风向分区风荷载谱识别方法

Along-wind load spectra identification method for a long-span concrete-filled steel-tube transmission tower

为了从风洞试验测量的位移响应中较好地识别出钢管混凝土输电塔的风荷载,对荷载识别过程进行了模拟。首先选择了3种类型的风荷载谱并将它们分区施加于输电塔的多质点模型上,利用随机振动理论计算出结构的位移功率谱;然后,推导出了从几个测点的位移功率谱识别分区风荷载谱的方法,并定义了评价识别效果的误差指标;最后,分析了测量精度、测点数量及位置、模态数及风荷载系数等对荷载识别精度的影响,得到一些对实际风洞试验具有重要指导价值的结论。

In order to better identify several wind load spectra of a long-span concrete-filled steel-tube transmission tower from displacements measured with wind tunnel tests, wind load identificaton processes were simulated with computer. Firstly, selecting three kinds of wind load spectra and exerting them on a model of transmission tower, the structure displacement power spectra were computed with random vibration method. Then, a method was introduced to identify several dynamic wind load spectra from the displacement power spectra of several measured points and error index was defined to evaluate identifieaton effectiveness. Finally, effects of some factors, such as, measurement accuracy, number and position of measured points, modes taken and wind load coefficient, et al on accuracy of wind load identification were analyzed and some important conclusions were drawn so as to guide actual wind tunnel tests.