Dominant Frequency Characteristics of Acoustic Emissions in White Marble During Direct Tensile Tests

Li, L. R.; Deng, Jiang; Zheng, Lin; Liu, J. F.

doi:10.1007/s00603-016-1162-2

Cited by 114 publications

(38 citation statements)

References 25 publications

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“…This observation indicates that micro-shear failure plays a dominant role for dried rock's failure under compression. This observation coincides with past findings for rock micro failure modes (Jaeger et al [32]; Li et al [29]).…”

Section: Microscopic Failure Mechanismsupporting

confidence: 93%

“…Figure 4 clearly demonstrates that there are two concentrations of dominant frequency bands in both dried and saturated rocks. Following the findings of Li et al [29] and Li [31], the feature of double dominant frequency bands is intrinsic for rocks is further confirmed by this observation, regardless of the water content in the rock specimen. As shown in Table 2, the range of dried specimens' percentage of high frequency AE is from 53.41% to 77.03% compared with 17.43% to 42.91% for the low frequency AE.…”

Section: Frequency Characteristicssupporting

confidence: 88%

“…Many researchers studied micro-failure mechanism of rock by employing AE technology [17,18,[21][22][23][24][25][26][27][28]. AE signal contains a series of parameters such as ib-value [18,21], AF(average frequency) and RA(Rise Time/Amplitude) [18,[21][22][23][24], energy and RMS (Root Mean Square) [17], dominant frequency [29] and so on. In addition, among them, the domain frequency AF and RA have been proved to be associated with the mode of microscopic failure [22][23][24][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

An Experimental Investigation of Moisture-Induced Softening Mechanism of Marble Based on Quantitative Analysis of Acoustic Emission Waveforms

2019

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The decrease of strength after saturation of rocks is known as moisture-induced softening. To date, there are numerous studies on the mechanism of moisture-induced softening of different rocks. However, due to a lack of effective observational methods, the microcosmic mechanism of moisture-induced softening still needs to be understood. We collected and processed acoustic emission (AE) signals during the uniaxial compression test of marble specimens. The results of spectral and statistical analysis show that two dominant frequency bands of AE waveforms exist regardless of the specimen's water content. Additionally, for the AE signals from the saturated specimens, the ranges of the low and high frequency bands are wider than dried rock samples. Besides, since the tensile and shear failures in the rock release low and high dominant frequency AE signals, respectively, the test results of this paper show that micro-shear and micro-tensile failures dominate the final failure of dried and saturated rocks, respectively.

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Section: Microscopic Failure Mechanismsupporting

confidence: 93%

Section: Frequency Characteristicssupporting

confidence: 88%

Section: Introductionmentioning

confidence: 99%

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An Experimental Investigation of Moisture-Induced Softening Mechanism of Marble Based on Quantitative Analysis of Acoustic Emission Waveforms

2019

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“…Surrounding the phenomenon of dual dominant frequency bands in the process of rock fracture, the AE signals of high frequency and low frequency are considered to be generated by shear and tension fracture, respectively [11]. Based on the above-mentioned basic viewpoints, some researchers have discussed the evolution process of shear and tension cracks in white marble under direct tensile test [11], uniaxial compression [12], direct tensile test and Brazilian test [13]. The dominant frequency identification method is referential, but the complexity of the rock fracture mechanism should still be considered.…”

Section: Introductionmentioning

confidence: 99%

Micro-Crack Mechanism in the Fracture Evolution of Saturated Granite and Enlightenment to the Precursors of Instability

Dong

Zhang

2020

Sensors

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To explore the potential precursors of rock instability, it is necessary to clarify the mechanism of micro-crack from fracturing to failure, which involves the evolution of fracture size, orientation, source model, and their relationships to the loading. The waveforms of acoustic emission (AE) recorded by the sensor network attached rock sample during laboratory tests provide a data basis for solving these problems, since these observations are directly related to the characteristics of the fracturing sources. Firstly, we investigated the source mechanism, looking at the rise angle and the average frequency (RA-AF) trends during five loading stages in a uniaxial compression test. Results show that the proportion of shear events significantly increases when approaching instability. Secondly, we calculated the moment tensor for each event, considering the uncertainties of P-wave polarity, azimuth, and the takeoff angles of the rays. Moment tensor solutions suggest that there are obviously more crack events than shear events in all loading stages. Moment tensor evolutions confirmed that the decreasing of isotropic component and the increment of double-couple can be used as precursors of rock fracturing development. Considering the limitations of these two methods, it is suggested that we should be concerned more about the proportions of individual failure components and their evolutions over time, instead of absolutely classifying the events into a certain source type.

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“…The AE phenomenon is defined as elastic mechanical waves associated with a rapid release of localized stress energy propagated within the material. AE monitoring is a useful tool for studying rock fracturing [10,11]. In order to understand the physical process generating seismicity within volcanic edifices, some studies have been based on monitoring an array of transducers around a rock sample, permitting the full-waveform capture, location, and analysis of microseismic events [12,13].…”

Section: Introductionmentioning

confidence: 99%

The Mechanical and Fracturing of Rockburst in Tunnel and Its Acoustic Emission Characteristics

Liu

Zhan

Zhang

et al. 2018

Shock and Vibration

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The phenomenon of acoustic emission (AE) is associated with rock failure and rock fracturing. In order to investigate the influence of tectonic stress on rockburst in tunnel, a biaxial loading experiment system was used in this study. The excavation operation is undertaken at the center of samples to monitor the tunnel forming process in situ, and the different horizontal stresses can be studied by using the AE monitoring technique. The dynamical fracturing process of the tunnel model was summarized, and the timing parameters of AE signals in rockburst stages were obtained. The curves of AE energy and cumulative AE energy with time show a "step-like" rising trend before the occurrence of rockburst. The evolution of macro-and mesocracks is captured, and the mechanical conditions for a "V-shaped" rockburst pit are derived. As the horizontal stress increases, the effect of excavation unloading becomes more pronounced, and the damage caused by the rockburst intensifies. In the early stage of rockburst evolution, the fracturing type follows a model of tensile-shear mix model. A positive relationship between the ratio of shear fracturing type and the horizontal stress can be noted when the rock is about to burst, and the high intensity and the high energy released of from the rock-fracturing event have become evident. Thus, the results indicate that one should focus on monitoring both sides of the surrounding rock of the tunnel so as to extract the characteristics of the process of tunnel in tunnel. The applications of biaxial loading system and during an excavation operation provide a useful tool to simulate the rock burst in tunnel at an engineering site.

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Dominant Frequency Characteristics of Acoustic Emissions in White Marble During Direct Tensile Tests

Cited by 114 publications

References 25 publications

An Experimental Investigation of Moisture-Induced Softening Mechanism of Marble Based on Quantitative Analysis of Acoustic Emission Waveforms

An Experimental Investigation of Moisture-Induced Softening Mechanism of Marble Based on Quantitative Analysis of Acoustic Emission Waveforms

Micro-Crack Mechanism in the Fracture Evolution of Saturated Granite and Enlightenment to the Precursors of Instability

The Mechanical and Fracturing of Rockburst in Tunnel and Its Acoustic Emission Characteristics

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