Structural Damage Identification Method Based On Wavelet Packet Energy Rate Of Change

The bridge structure damage recognition and health monitoring technology has become one of hot topics in the field of civil engineering research. This paper uses the value simulation method, together with wavelet packet energy rate index and the second generation of wavelet energy rate index, to identify the damage position of simple supported beam. Then study the influence of noise to this two structure damage recognition methods of simple supported beam, and the result of value simulation shows this two structure damage recognition methods still can identify the damage position of simple supported beam after implementing noise reduction on structure dynamic response signals. The main conclusions of this paper are:1. The wavelet packet energy rate index is quite sensitive to structure damage. The result of value simulation shows, at the structure damage position, the difference of the wavelet packet energy rate index and believable upper limit is far higher than other measured positions. Then we can determine the structure damage position, but considering the influence of 5% noise, this method cannot be used to do damage recognition of structure.2. Proposes the method to do damage recognition of structure based on the second generation of wavelet energy rate index. The result of value simulation shows, the second generation of wavelet energy distribution is quite sensitive to structure damage, and at the structure damage position, the difference of the wavelet energy rate index and believable upper limit is far higher than other measured positions. That proves he second generation of wavelet energy rate index can be used to determine the structure damage position.3. Signals measured in actual project will include noise. Therefore, in order to apply the structure damage recognition method proposed by this article in actual project, we must consider the influence of noise to the recognition method. The noise has great influence to do damage recognition with wavelet packet energy rate index and the second generation of wavelet energy rate index. So before doing damage recognition in actual project, we should do noise reduction to dynamic signal obtained on-site using wavelet noise reduction method first, and then do damage recognition with wavelet packet energy rate index and the second generation of wavelet energy rate index. After doing noise reduction to dynamic signal with noise, we can do better on determining the structure damage position with wavelet packet energy rate index and the second generation of wavelet energy rate index.