A new direct method for updating structural models based on measured modal data
A new direct method for updating structural models based on measured modal data
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DOI：
10.1016/j.engstruct.2008.07.011
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发表时间：
2009
影响因子：
5.5
通讯作者：
Yeong-Bin Yang;Chen Yung-Hsiang
中科院分区：
文献类型：
--
作者：
Yeong-Bin Yang;Chen Yung-Hsiang
提出了一种直接方法来更新结构模型的质量和刚度矩阵，以便它可以准确地再现结构测量的频率。首先，我们假设仅测量了结构的第一本征模式。利用特征向量的正交条件导出更新矩阵，并用模态矩阵代替关注的特征向量，解决方程数不足的问题。然后将这样的过程推广到处理测量结构的前几个本征模式的情况。对于所有研究的例子，结果表明，当前更新模型预测的固有频率与测量的一致。更新后的模型具有物理意义，因为系统矩阵的带宽得以保留。该方法的优点是计算简单、高效、准确。它可以很容易地应用于包含大量自由度的结构。
A direct method is proposed for updating the mass and stiffness matrices of a structural model such that it can accurately reproduce the frequencies measured for the structure. To start, we assume that only the first eigen mode was measured for the structure. The updated matrices are derived by utilizing the orthogonality conditions for the eigenvectors, and by replacing the eigenvector of concern with the modal matrix, to resolve the problem of insufficient number of equations. Such a procedure is then generalized to deal with the case where the first few eigenmodes are measured for the structure. For all the examples studied, it was demonstrated that the natural frequencies predicted by the present updated model agree well with the measured ones. The updated model is physically meaningful as the bandwith of the system matrices is preserved. The merit of the present method is its simplicity, efficiency, and accuracy in computation. It can be easily applied to structures that contain a large number of degrees of freedom.