Operational Modal Parameter Identification from Power Spectrum Density Transmissibility
Operational Modal Parameter Identification from Power Spectrum Density Transmissibility
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DOI：
10.1111/j.1467-8667.2011.00735.x
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发表时间：
2012-03
期刊：
影响因子：
--
通讯作者：
W. Yan;W. Ren
中科院分区：
文献类型：
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作者：
W. Yan;W. Ren
翻译后摘要：在操作条件下的环境或自然激励的操作模态分析最近引起了极大的关注。本文提出用功率谱密度传递率（PSDT）提取结构的工作模态参数。证明了PSDT与系统极点处的外加激励和传递输出无关。因此，模态频率和振型可以通过组合PSDT与不同的传输输出，而不是不同的负载条件下，只需要一个负载条件的输出。通过一个五层剪力建筑在不同楼层受到一组不相关的力来验证PSDTs的性质，并说明所提出的方法的准确性。此外，一个钢管混凝土中承式拱桥在运营条件下的现场测试被用作一个真实的案例研究。从目前开发的方法获得的识别结果进行了比较，从峰值拾取方法，随机子空间识别，和有限元分析提取的。结果表明，该方法识别的工作模态参数与其他独立方法识别的工作模态参数吻合较好。真实的应用于全尺寸桥梁的现场操作振动测量表明，所提出的PSDT能够识别结构的操作模态参数（固有频率和振型）。
Abstract: Operational modal analysis subjected to ambient or natural excitation under operational conditions has recently drawn great attention. In this article, the power spectrum density transmissibility (PSDT) is proposed to extract the operational modal parameters of a structure. It is proven that the PSDT is independent of the applied excitations and transferring outputs at the system poles. As a result, the modal frequencies and mode shapes can be extracted by combing the PSDTs with different transferring outputs instead of different load conditions where the outputs from only one load condition are needed. A five‐story shear building subjected to a set of uncorrelated forces at different floors is adopted to verify the property of PSDTs and illustrate the accuracy of the proposed method. Furthermore, a concrete‐filled steel tubular half‐through arch bridge tested in the field under operational conditions is used as a real case study. The identification results obtained from currently developed method have been compared with those extracted from peak‐picking method, stochastic subspace identification, and finite element analysis. It is demonstrated that the operational modal parameters identified by the current technique agree well with other independent methods. The real application to the field operational vibration measurements of a full‐sized bridge has shown that the proposed PSDTs are capable of identifying the operational modal parameters (natural frequencies and mode shapes) of a structure.