Study On The Failure Omen Information Of Hydrous Rock Based On Wavelet Packet Analysis

The deformation and crack propagation of materials under stress is an important mechanism for structural failure, the energy will be released instantaneously when stress concentration occurred on the local area of materials. So, it’s actually of researching the failure information of rock with moisture contents from the terms of energy. Nevertheless, the singles had been acquired were difficult to be analyzed comprehensively and systematically and effectively due to its’non-stationary by the traditional signal processing methods in the process of the energy was received by the form of acoustic emission signal. Consequently by which way to interpret the energy changes that were arisen at the time of rock failure better has become a hot topic for both Chinese and foreign professionals and scholars to study.In the first of all, the author got a large number of acoustic emission data through the uniaxial compression experiment of rock with different saturation, afterwards researches the change regulation of sandstone AE event numbers along with the changes of saturation. Next, the acoustic emission signal is processed by the wavelet packet then the noise reduction effectively by using the wavelet transform and the wavelet packet transform at the same time researches the energy band’s distribution characteristics of rock with moisture contents and achieves the major band during the failure of that through the analysis of the wavelet packet energy band. Once more, the writer obtains the information that at what time the rock with moisture contents failure as a result of counting the value of the lipschitz α by wavelet packet decomposition and reconstruction based on the principle of time sequence and using the oddity of signal. At last the acoustic emission signal is decomposed and reconstructed by wavelet packet so as to get the wavelet packet node coefficient and then using it as feature vector to calculate the eigenvalue of the wavelet packet node coefficient to predict the omen information of rock with moisture contents by which changes suddenly according to a matrix can be expressed by all its feature vector and the corresponding characteristic value of each vector, on behalf of the matrix in the vector of the contribution rate of the theory and based on when the signal is changed, the signal frequency component will produce different inhibition or enhancement, compared to the signal and rupture, rupture of certain frequency band signal before a short time within the energy surges and some parts will drop thoughts.Although it is very different in the signal energy of rock between in the laboratory and in practical engineering, it is similar in the principle and some other aspects. There is important practical significance to the development trends and patterns of impaired forecasting rock and to predict the omen information of rock with moisture contents.