Influence of Joint Angle on the Acoustic Emission Evolution Characteristics and Energy Dissipation Rule of Rock Mass

2020 ◽  
Author(s):  
Zhaofeng Chen ◽  
Linrong Xu ◽  
Yonghui Shang
Keyword(s):  
Acoustic Emission ◽  
Rock Mass ◽  
Energy Dissipation ◽  
Joint Angle ◽  
Evolution Characteristics

scholarly journals The results of monitoring of hydroimpulsive disintegration of outburst-prone coal seams using ZUA-98 system

2020 ◽  
Vol 168 ◽  
pp. 00068
Author(s):  
Vasyl Zberovskyi ◽  
Kostiantyn Sofiiskyi ◽  
Rishard Stasevych ◽  
Artem Pazynych ◽  
Jan Pinka ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Rock Mass ◽  
Coal Seam ◽  
High Frequency ◽  
Strain State ◽  
Monitoring And Evaluation ◽  
Dynamic State ◽  
Coal Seams ◽  
Gas Dynamic ◽  
Mine Workings

The paper represents the results of monitoring and evaluation of the efficiency of hydroimpulsive disintegration of outburst-prone coal seams in the stopes of development mine workings using a system of sound detecting facilities. Methods of acoustic emission control have been considered as well as the monitoring tasks to evaluate rock mass conditions before the procedure and after it inclusive of the results of sound accompaniment of hydraulic disintegration of the coal seam. It has been determined that the higher concentration of stresses within the rock mass is, the more efficient action of high frequency self-oscillations of cavitation transmitter is on both the fissuring and changes in gas-dynamic state of the coal seam. It has been recommended to apply a mode of impulsive fluid pumping under the conditions where coal seam is in the stress-strain state.

scholarly journals Energy dissipation via acoustic emission in ductile crack initiation

2016 ◽  
Vol 199 (1) ◽  
pp. 89-104 ◽  
Author(s):  
J. A. Cuadra ◽  
K. P. Baxevanakis ◽  
M. Mazzotti ◽  
I. Bartoli ◽  
A. Kontsos
Keyword(s):  
Acoustic Emission ◽  
Energy Dissipation ◽  
Crack Initiation ◽  
Ductile Crack

The study of a fatigue crack propagation in titanium Grade 2 using analysis of energy dissipation and acoustic emission data

2019 ◽  
Vol 210 ◽  
pp. 312-319 ◽  
Author(s):  
A.N. Vshivkov ◽  
A. Yu. Iziumova ◽  
I.A. Panteleev ◽  
A.V. Ilinykh ◽  
V.E. Wildemann ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Energy Dissipation ◽  
Crack Propagation ◽  
Fatigue Crack Propagation ◽  
Emission Data ◽  
Titanium Grade

scholarly journals Failure warning of hydrous sandstone based on electroencephalogram technique

2018 ◽  
Vol 38 ◽  
pp. 02015
Author(s):  
Kai Tao ◽  
Wei Zheng
Keyword(s):  
Computed Tomography ◽  
Acoustic Emission ◽  
Rock Mass ◽  
Real Time ◽  
Assessment Methods ◽  
Structural Failure ◽  
Failure Assessment ◽  
Electroencephalogram Eeg

Sandstone is a type of rock mass that widely exists in nature. Moisture is an important factor that leads to sandstone structural failure. The major failure assessment methods of hydrous sandstone at present cannot satisfy real-time and portability requirements, especially lacks of warning function. In this study, acoustic emission (AE) and computed tomography (CT) techniques are combined for real-time failure assessment of hydrous sandstone. Eight visual colors for warning are screened according to different failure states, and an electroencephalogram (EEG) experiment is conducted to demonstrate their diverse excitations of the human brain’s concentration.

scholarly journals Investigation for Influences of Seepage on Mechanical Properties of Rocks Using Acoustic Emission Technique

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Saisai Wu ◽  
Xiaohan Zhang ◽  
Junping Li ◽  
Zhao Wang
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Rock Mass ◽  
Shear Failure ◽  
Great Influence ◽  
Average Energy ◽  
Acoustic Emission Technique ◽  
Failure Patterns ◽  
Initial Rupture ◽  
Emission System

The behavior of rock mass is governed by the properties of both the rock material and discontinuities in the rock mass. Surrounding environments including the existence of water also have a great influence on the behavior and mechanical properties of rocks. In this study, a novel-designed compression and seepage testing system, associated with an acoustic emission system, was designed and constructed. The changes in the specimens resulting from the uniaxial compression were monitored by an acoustic emission technique. The characteristics of the acoustic emission parameters at different stages including compaction and crack initiation, crack propagation, and catastrophic failure were analyzed. The existence of seepage had direct influences on the mechanical properties and failure patterns of the specimens. The specimens tested in pure compression conditions demonstrated strong burst proneness and ruptured into separate pieces, while for the specimens with seepage, no burst proneness was observed and the specimens tended to fail along a macroscopic shear failure plane. The highest average energy of the acoustic signal occurred at the stage of initial rupture of rock specimens, rather than at the stage of widespread rupture. The studies explored the possibilities of using the acoustic emission technique to investigate the problems associated with the seepage in geotechnical and rock engineering and provided meaningful results for further research in this field.

scholarly journals The Effect of Confining Pressure and Water Content on Energy Evolution Characteristics of Sandstone under Stepwise Loading and Unloading

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Shuren Wang ◽  
Paul Hagan ◽  
Yanhai Zhao ◽  
Xu Chang ◽  
Ki-Il Song ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Water Content ◽  
Elastic Energy ◽  
Strain Energy ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Energy Evolution ◽  
Evolution Characteristics ◽  
Loading And Unloading ◽  
Stepwise Loading

To investigate the mechanical properties and energy evolution characteristics of sandstone depending on the water contents and confining pressure, the uniaxial and triaxial tests were conducted. The test results show that the strain energy was stored in the sandstone samples at the prepeak stage, and that is suddenly released when the failure occurred, and energy dissipation is sharply increased at the postpeak stage. The damage and energy dissipation characteristics of the samples are observed clearly under the stepwise loading and unloading process. The critical strain energy and energy dissipation show a clear exponential relationship. The critical elastic energy decreases linearly as the water content increases. As the confining pressure increases, the critical elastic energy of the samples transforms from linear to exponential. The concept of energy enhancement factor is proposed to characterize the strengthening effect induced by the confining pressure on the energy storage capacity of the rock samples. The energy evolution of the sandstone samples is more sensitive to the confining pressure than that of the water content.

Rock mass acoustic emission detection using DFB fiber lasers

2012 ◽  
Author(s):  
Wenzhu Huang ◽  
Huaixiang Ma ◽  
Wentao Zhang ◽  
Fang Li ◽  
Yanliang Du
Keyword(s):  
Acoustic Emission ◽  
Rock Mass ◽  
Fiber Lasers ◽  
Emission Detection

scholarly journals Energy Dissipation and Damage Evolution Characteristics of Salt Rock under Uniaxial Cyclic Loading and Unloading Tension

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Anqi Zhu ◽  
Jianfeng Liu ◽  
Zhide Wu ◽  
Lu Wang ◽  
Hejuan Liu ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Damage Evolution ◽  
Damage Variable ◽  
Plastic Deformation Zone ◽  
Salt Rock ◽  
Cyclic Loading And Unloading ◽  
Cyclic Tension ◽  
Evolution Characteristics ◽  
Fracture Crack ◽  
Strength And Deformation

Salt rock has been regarded as the optimal surrounding rock for underground gas storage (UGS), and it is occasionally subjected to cyclic tension because of the gas injection and production of salt cavern, which leads to the change in mechanical properties of salt rock. In this paper, a laboratory study is conducted to investigate the energy dissipation and damage evolution characteristics of salt rock under uniaxial cyclic tension monitored by acoustic emission (AE) machine. Compared to monotonic tension, both tensile strength and deformation capacity of salt rock are enhanced under cyclic tension. The fracture crack is approximately a single linear crack with large elliptical plastic deformation zone, which is consistent with the spatial distribution of AE events. In yield stage, the proportion of dissipative energy increases first but decreases subsequently. The relationship between AE energy-based damage variable and displacement is established. It is concluded that the damage variable is a piecewise power correlation with displacement while the growth rate of damage variable increases in the pre-peak stage but decreases in post-peak stage.

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