Spectrum Characteristics of Acoustic Emission Signals for Sandstone Instability
In order to predict the rock rupture and instability, acoustic emission signals of natural sandstones and hydrous sandstones are analyzed through the Fast Fourier Transform and the Welch method. It is found that the acoustic emission signals of the hydrous sandstones have narrower range of frequen...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Eastern Macedonia and Thrace Institute of Technology
2014-09-01
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| Series: | Journal of Engineering Science and Technology Review |
| Subjects: | |
| Online Access: | http://www.jestr.org/downloads/Volume7Issue4/fulltext147414.pdf |
| Summary: | In order to predict the rock rupture and instability, acoustic emission signals of natural sandstones and hydrous
sandstones are analyzed through the Fast Fourier Transform and the Welch method. It is found that the acoustic emission
signals of the hydrous sandstones have narrower range of frequency spectrum and lower average dominant frequencies
than the natural sandstones. The dominant frequencies of the acoustic emission signals of the hydrous sandstones reduce
more dramatically. In addition, two types of Welch power spectrum of the acoustic emission signals in terms of the shape
are presented in this paper, which are named Type A and Type B. The Type B Welch power spectrum emerges when the
acoustic emission occurs frequently, in which a disaster tends to appear. Time baselines are selected when relative
stronger cracks and crack coalescence happens. We find that the greater signals energy at the time baseline, the higher
probability of occurrence of Type B spectrum appears before the time baseline. Also, the probabilities of Type B before
the corresponding the baseline time of rock last rupture in hydrous sandstones are higher than that of natural sandstones. |
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| ISSN: | 1791-2377 1791-2377 |