Analysis Of Errors And Approximations In The Use Of Modal Co-Ordinates
Analysis Of Errors And Approximations In The Use Of Modal Co-Ordinates
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DOI：
10.1006/jsvi.1994.1424
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发表时间：
1994-10
影响因子：
4.7
通讯作者：
Aldo Sestieri;Samir R. Ibrahim
中科院分区：
文献类型：
--
作者：
Aldo Sestieri;Samir R. Ibrahim
摘要 几种更新程序和其他模态分析应用中的基本操作涉及将从实验测试中确定的复杂模态转换为理论模型的典型真实模态。在这种变换中，通常采用几种近似值。本文讨论了其中两个近似值：第一个是指将复模态向实模子空间进行级数展开，通常用于复模态的归一化。第二个用于高级模态分析应用，通过实模态矩阵将物理阻尼坐标与模态坐标联系起来。通过分析发展和从离散模型获得的数值结果给出了对这些假设的局限性的解释。
Abstract A basic operation in several updating procedures and other modal analysis applications concerns the transformation of the complex modes, identified from experimental tests, into the real ones typical of theoretical models. In this transformation several approximations are normally adopted. This paper presents a discussion of two of these approximations: the first refers to a series expansion of the complex modes into the subspace of real modes, commonly used for normalization of complex modes. The second, used in advanced modal analysis applications, relates the physical damped co-ordinates to the modal ones through the real modal matrix. An explanation of the limitations of these assumptions is given through analytical developments and numerical results obtained from a discrete model.