Autocorrelation Analysis in Time and Frequency Domains for Passive Structural Diagnostics
Autocorrelation Analysis in Time and Frequency Domains for Passive Structural Diagnostics
复制标题
用于被动结构诊断的时域和频域自相关分析
DOI：
10.1155/2013/204878
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发表时间：
2013
影响因子：
--
通讯作者：
Mikio Tohyama
中科院分区：
文献类型：
--
作者：
Satoru Goto;Yoshinori Takahashi;Mikio Tohyama
本文讨论了利用时域和频域自相关函数估计结构模态频率的方法。通过流行的结构健康监测方法进行定期检查，例如“锤击试验”，听力对于区分结构状况之间的差异非常有用。听觉检测音高和音调，并且已知听觉过程与从自相关函数计算的波周期性有关。因此，在锤击试验的基础上，可以用自相关法估计模态频率，这与听觉相似。针对非平稳噪声环境下的结构恒值健康监测问题，提出了利用自相关估计模态频率的方法。首先，受听觉基音检测的启发，利用时域的自相关性估计基频模态频率。第二，更高的模态频率成分也分析了使用自相关在频域与音调的歧视。根据在未知非平稳噪声条件下进行的缩尺模型试验的结果，利用自相关函数的周期直方图推导出基本模态频率的周期。此外，还讨论了非平稳噪声下高阶模态频率的估计问题。
In this paper, modal frequency estimation by using autocorrelation functions in both the time and frequency domains for structural diagnostics is discussed. With popular structural health monitoring methods for periodic inspections such as with the “hammering test,” hearing is very useful for distinguishing differences between structural conditions. Hearing detects pitch and tone, and it is known that the auditory process is related to wave periodicity calculated from autocorrelation functions. Consequently, on the basis of the hammering test, modal frequencies can be estimated by autocorrelation, the same as hearing. In this paper, modal frequencies were estimated by using autocorrelation for constant structural health monitoring under a nonstationary noise condition. First, fundamental modal frequencies were estimated by using the autocorrelation of the time domain which was inspired by pitch detection of hearing. Second, higher modal frequency compositions were also analyzed by using autocorrelation in the frequency domain as with tones discrimination. From the results by conducting scale‐model experiments under unknown nonstationary noise conditions, periods of fundamental modal frequency were derived by using periods histogram of autocorrelation functions. In addition, higher modal frequency estimation under nonstationary noises was also discussed.