基于特征系统实现算法的输电塔气动阻尼风洞试验研究

发布时间：2018-07-05 16:59

本文选题：输电塔 + 气动阻尼　；参考：《振动与冲击》2014年21期

【摘要】：为研究输电塔结构环境激励下的气动性能,采用特征系统实现算法(ERA)对风洞试验结果进行模态参数识别,提出表征各阶模态脉冲响应振幅的模态参与因子(MPF)作为识别系统模态的参数,利用各阶模态参与因子和相应的特征值推导了模态能量贡献(MEC)的估算公式,利用模态参与因子和模态能量贡献自动提取系统模态以减小识别中的主观影响。比较了试验结果与准定常理论的异同,讨论了气动阻尼与平均风速和风向的关系。结果表明输电塔结构气动阻尼多为正阻尼,顺风向随风速的增大而增大,横风向基本保持定值且未出现负阻尼,气动阻尼与平均风速分量之间存在非线性关系,因而在准定常理论基础上通过引入高阶项对试验结果进行了拟合。
[Abstract]:In order to study the aerodynamic performance of transmission tower under ambient excitation, the characteristic system realization algorithm (ERA) is used to identify the modal parameters of wind tunnel test results. The modal participation factor (MPF), which represents the amplitude of the pulse response of each mode, is proposed as the parameter for identifying the mode of the system. The estimation formula of the modal energy contribution (MEC) is derived by using the participating factor of each mode and the corresponding eigenvalue. The modal participation factor and modal energy contribution are used to automatically extract the modal of the system to reduce the subjective influence in the identification. The similarities and differences between the experimental results and the quasi-steady theory are compared, and the relationship between aerodynamic damping and mean wind speed and wind direction is discussed. The results show that the aerodynamic damping of transmission tower structure is mostly positive damping, the downstream wind direction increases with the increase of wind speed, and the crosswind direction is basically constant and no negative damping, and there is a nonlinear relationship between the aerodynamic damping and the average wind speed component. Therefore, the experimental results are fitted by introducing higher order terms on the basis of quasi-steady theory.
【作者单位】：同济大学建筑工程系;
【分类号】：TU312.1

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