scholarly journals An experimental study on the damage and acoustic emission character of raw coalunder uniaxial compression condition

2021 ◽  
Vol 25 (6 Part B) ◽  
pp. 4537-4543
Author(s):  
Peng Gong ◽  
Zhan-Guo Ma ◽  
Xiao-Yan Ni ◽  
Yang Li ◽  
Yong-Heng Chen
Keyword(s):  
Experimental Study ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Damage Model ◽  
Damage Variable ◽  
Primary Crack ◽  
Crack Generation ◽  
Compression Condition

In the paper, the acoustic emission character is analyzed using a new damage variable which is defined based on ring-down count or energy count of acoustic emission and the damage model of raw coal under uniaxial compression is thus established. The results show that acoustic emission information can reflect inter?nal damage of raw coal and is closely related with primary crack compression and evolutionary course of new crack generation, growth, and connectivity.

Acoustic emission characteristics and damage model of cement mortar under uniaxial compression

2019 ◽  
Vol 213 ◽  
pp. 377-385 ◽  
Author(s):  
Qingheng Gu ◽  
Qing Ma ◽  
Yunliang Tan ◽  
Zhichuang Jia ◽  
Zenghui Zhao ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Cement Mortar ◽  
Damage Model ◽  
Emission Characteristics

Research on Landscape Limestone Damage and Deformation under Uniaxial Compression Based on Acoustic Emission

2013 ◽  
Vol 423-426 ◽  
pp. 914-919 ◽  
Author(s):  
Yong Qin Xiao ◽  
Yi Ping Wan ◽  
Bao Xian Liu
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Damage Evolution ◽  
Detection System ◽  
Damage Model ◽  
Mechanical Damage ◽  
Test System ◽  
Emission Feature ◽  
Internal Damage ◽  
Emission Parameter

In order to establish the relation between acoustic emission parameter and rock mechanical damage mechanism, as well as to better figure out landscape limestone damage and deformation influenced by uniaxial compression, MTS815 rock mechanical electro-hydraulic servo test system and 8CHSPCI-2 acoustic emission and detection system are applied to implement a test and research on damage evolution of limestone under uniaxial compression and the corresponding acoustic emission feature. On this basis, the acoustic emission feature of limestone under uniaxial compression is analyzed. Moreover, based on the damage variable of normalized accumulated emission ringing count, the uniaxial compression limestone damage model based on acoustic emission feature is established, and the damage evolution curve and equation of limestone is figured out as well. Shown by the research, acoustic emission information reflects the internal damage of limestone, and is closely related with densification of inner original fracture, as well as emerging, developing, and merging of new fractures. The acoustic emission feature of limestone perfectly describes its deformation and damage evolution.

Study on Energy Accumulation and Damage Evolution of the Coal and Rock Using Acoustic Emission Test

2011 ◽  
Vol 105-107 ◽  
pp. 1597-1602 ◽  
Author(s):  
You Gang Wang ◽  
Xiang Feng Liu
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Damage Evolution ◽  
Damage Mechanics ◽  
Solid Material ◽  
Damage Variable ◽  
Geometrical Parameters ◽  
Compression Process ◽  
Energy Accumulation ◽  
Ae Energy

Rocks and other rocklike solid materials have inherent defects inside. The defects of rock will be evolved under loading. The evolution process and extent of defects can be described by the damage variable. But which physical or geometrical parameters can be used to define the damage, there has no consistent conclusion domestic and aboard. Moreover, limited by the method of experimental, it is difficult to obtain the parameters to depict the damage variable directly. In order to obtained the evolution law of the interior defects in the solid material, the non-conduct geophysical prospecting measure as AE (Acoustic Emission) will be the leading measure to prospect the interior defects and it’s evolution under outside loading. In the present paper, the AE method was used to obtain the AE parameters during the uniaxial compression process of coal and rock. Therefore, uniaxial compression and AE tests on coal and mudstone were conducted, and the curves among the AE energy accumulation, stress and strain were obtained after analyzing the results of tests data. Based on the principle of damage mechanics and thermodynamics, the damage evolution of coal and rock was deduced through analyzing the experimental results, the curves of damage and AE accumulation were obtained also. By analyzing and fitting the curves of damage and AE energy accumulation, the relation between the AE energy accumulation and stress-strain was obtained and verified through the experimental data.

scholarly journals Experimental Study on Acoustic Emission Characteristics of Dry and Saturated Basalt Columnar Joints under Uniaxial Compression and Tensile Damage

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Liu Gang ◽  
Xiao Fu-kun ◽  
Cheng Qian-long ◽  
Qin Tao
Keyword(s):  
Experimental Study ◽  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Failure Modes ◽  
Compression Tests ◽  
Steady Growth ◽  
Columnar Joints ◽  
Ae Location ◽  
Location Map ◽  
Tensile Damage

An experimental study was carried out to investigate the acoustic emission (AE) characteristics of dry and saturated basalt columnar joints under uniaxial compression and tensile damage by using the TAW-2000 rock experiment system and SH-IIAE system for the whole loading. The results show that the softening coefficient of uniaxial compressive strength and the tensile strength was 0.78 and 0.68, respectively, and water increases the sample complexity and has a strong effect on its strength. The dry sample under uniaxial compression at the beginning of loading produced a large number of AE signals, and the AE signal showed steady growth as the load increased, but the sample destruction occurred during the blank period, which can be used as a precursor of instability. From the amplitude-time-energy diagram, it can be found that as amplitude increases with hit, energy decreases, which shows an obvious triangle relation. From the uniaxial compression damage AE location map, we can find that AE events exist disorderly and show scattered distribution in each area. From the failure modes and sections of tension and uniaxial compression tests, it is found that there are many layers and fissures in rock samples, which are consistent with AE location.

scholarly journals Determination of Damage Constitutive Behavior for Rock Salt Under Uniaxial Compression Condition with Acoustic Emission

2015 ◽  
Vol 9 (1) ◽  
pp. 75-81 ◽  
Author(s):  
Chen Jie ◽  
Zhang Junwei ◽  
Ren Song ◽  
Li Lin ◽  
Yin Liming
Keyword(s):  
Acoustic Emission ◽  
Uniaxial Compression ◽  
Rock Salt ◽  
Shear Failure ◽  
Strain Curve ◽  
Failure Surface ◽  
Uniaxial Compression Test ◽  
Damage Development ◽  
Whole Process ◽  
Compression Condition

The mechanical characteristics of rock salt have an important influence on the safety of the salt cavity. The acoustic emission (AE) technique was used to analyze the generation of microcracks in rock salt under uniaxial compression condition. By monitoring acoustic emission in whole process of stress - strain curve under uniaxial compression test, the damage characteristic of rock salt is obtained. The AE rate-strain curve is able to reflect the damage development process with better consistency evident with the cracks generating. The failure form of rock salt is mainly the shear failure under condition of low loading strain rate. After shear failure, a lot of small crushed particles spread on the surface of the failure surface. A damage constitutive model of rock salt is determined on the basis of acoustic emission characteristics, which could reflect the strength and deformation characteristics before the peak strength.

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