Summary: | 碩士 === 國立成功大學 === 系統及船舶機電工程學系碩博士班 === 93 === Abstract
This article study wavelet transforms to detect the defect of structure. All Structures have there physical characteristics. Property will change, and formed in-continuity point. With wavelet transformation, we can detect this in-continuity mode of structure. Further more, we can point out its location. Then, with singular index, we will know the level of damage and identify the two defects.
We use one damaged cantilever beam for example, with finite element method analysis to precede vibration mode, then use wavelet transformation to detect the damage. As for the experimental analysis, first, we measure the damaged cross beam, get their vibration signal, with wavelet packet node norm to transform the vibration signal. So we can get the parameters of vibration mode. After that we can use wavelet transformation analysis get the damage position of experienented beam.
For the cantilever beam, we can use the similar method. All different king of damage for the sophisticated beam, this analysis method can identify their position and type of defect, with small error and uncertainty. It also can identify the cross beam position of damage and of crossing. The software(ANSYS)analysis result confirm the experiment data. And the method have its application or other structures.
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