Cable local vibration has little effect on the modal frequency, but more on the modal energy distribution.

索的局部振动虽然对结构主要振型的频率影响不大，但对振型能量分布有比较明显的影响。

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Generalized into local frequency from integral frequency, the method of joint time-frequency distribution effectively analyzes the signal based on the variation of frequency with time.

联合时频分布方法把整体频谱推广到局部频率，根据频率随着时间的变化情况，对信号进行有效的分析。

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After signal local wave decomposition, the information entropy according to time-frequency distribution was established, and it was used as characteristic parameter for fault recognition.

对信号进行局域波分解后，建立基于时频分布的信息熵，以此作为故障识别的参数。

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