Acoustic emission and stages of the crack-formation process in rock

Acoustic Emissions at High and Low Frequencies During Compression Tests in Brittle Materials

“…During nucleation and growth of microcracks, high‐frequency acoustic emissions (AE) are observable. As soon as microcracks coalesce to form cracks of large length, the frequencies drop off and ELE clearly appear in addition to AE [13, 14].…”

“…It is established by numerous investigations that the AE activity varies during damage process. The AEs released in various stages of this process are distinguished by its own energy and furthermore are concentrated in various sections of the frequency range; at the start of the damage process (microcrack initiation), AE is emitted at high frequencies, and later (microcrack coalescence into cracks of large length), the AE frequencies drop off to few kHz or less [13, 14].…”

Damage characterization of red sandstones using uniaxial compression experiments

“…According to the test results presented here, the high-frequency AE events mainly occur aer the damage strength point and the low-frequency AE events also increase simultaneously. Based on the research conclusions presented in previous papers, 27,28 this paper draws…”

Improvement of technical and methodical means of local control burst- hazard of rock mass

“…Using the latter, depending on the technical means used, it is possible to carry out both local and regional monitoring of the state of the rock mass. It is based on the experimentally observed and theoretically studied phenomenon of acoustic emission (AE), which accompanies the process of mechanical loading and destruction of rocks [2].…”