数据驱动随机子空间算法的桥梁运营模态分析.pdfVIP

学兔兔 桥梁建设 2011年第6期 文章编号：1003—4722(2011)06—0016—06 数据驱动随机子空间算法的桥梁运营模态分析 单德山，徐 敏 (西南交通大学土木工程学院桥梁工程系，四川成都610031) 摘 要：以某自锚式悬索桥模型试验为研究背景，采用数据驱动随机子空间识别算法和改进 稳定图方法对桥梁结构运营模态分析进行研究。为解决数据驱动随机子空间识别中的系统定阶和 虚假模态问题，采用奇异熵增量进行系统定阶，并对稳定图进行改进，实现了虚假模态的识别与剔 除，最终达到了精确识别桥梁结构模态参数的目的。采用模型试验在不同数据采集方案下的测试 数据，识别该模型桥相应测试条件下的模态参数，将识别结果分别与ANSYS理论计算值、DAsY— Lab模态参数识别结果进行比较，验证了所提方法及自编程序的正确性，该方法可应用于桥梁结构 的运营模态分析中。 关键词：悬索桥；环境振动；随机子空间识别；数据驱动；模态参数 中图分类号：U441．3 文献标志码：A Operational Modal Analysis of Bridge Structure Based on Data— Driven Stochastic Subspace Identification Algorithm sHAN De-shan，XU Min (Department of Bridge Engineering，School of Civil Engineering， Southwest Jiaotong University，Chengdu 610031，China) Abstract：The model test of a self—anchored suspension bridge iS taken as the research back— ground，the data～driven stochastic subspace identification(Data—Driven SSI)algorithm and the improved stabilization diagram method are employed to study the operational modal analysis of bridge structure．For solving the problem of the system order determination and false modal pa— rameters in the Data—Driven SSI，the singular entropy increment is introduced to determine the system order and to improve the stability diagram，the false modal parameters are therefore iden— tified and eliminated and eventually the goal of accurately identifying the modal parameters of the bridge structure is attained．By using the testing data of the model test under different