The influence of stiffness of the true triaxial testing machine on the rupturing and acoustic emission of rocks and its correlation with seismic activities

1992 ◽  
Vol 5 (2) ◽  
pp. 367-379 ◽  
Author(s):  
Zhaoyong Xu ◽  
Shirong Mei ◽  
Cantao Zhuang ◽  
Peilin Li
Keyword(s):  
Acoustic Emission ◽  
Testing Machine ◽  
Triaxial Testing ◽  
True Triaxial ◽  
Triaxial Testing Machine

scholarly journals The Static Breaking Technique for Sustainable and Eco-Environmental Coal Mining

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Hao Bing-yuan ◽  
Huang Hui ◽  
Feng Zi-jun ◽  
Wang Kai
Keyword(s):  
Growth Rate ◽  
Acoustic Emission ◽  
Testing Machine ◽  
Vertical Direction ◽  
Rock Breaking ◽  
Extended Model ◽  
True Triaxial ◽  
Hard Roof ◽  
Expansion Time ◽  
Applied Forces

The initiating explosive devices are prohibited in rock breaking near the goaf of the highly gassy mine. It is effective and applicable to cracking the hard roof with static cracking agent. By testing the static cracking of cubic limestone (size:200×200×200 mm) with true triaxial rock mechanics testing machine under the effect of bidirectional stress and by monitoring the evolution process of the cracks generated during the acoustic emission experiment of static cracking, we conclude the following: the experiment results of the acoustic emission show that the cracks start from the lower part of the hole wall until they spread all over the sample. The crack growth rate follows a trend of “from rapidness to slowness.” The expansion time is different for the two bunches of cracks. The growth rates can be divided into the rapid increasing period and the rapid declining period, of which the growth rate in declining period is less than that in the increasing period. Also, the growth rate along the vertical direction is greater than that of the horizontal direction. Then the extended model for the static cracking is built according to the theories of elastic mechanics and fracture mechanics. Thus the relation formula between the applied forces of cracks and crack expansion radius is obtained. By comparison with the test results, the model proves to be applicable. In accordance with the actual geological situation of Yangquan No. 3 Mine, the basic parameters of manpower manipulated caving breaking with static crushing are settled, which reaps bumper industrial effects.

scholarly journals Acoustic Emission and K-S Metric Entropy as Methods for Determining Mechanical Properties of Composite Materials

Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 145
Author(s):  
Lesław Kyzioł ◽  
Katarzyna Panasiuk ◽  
Grzegorz Hajdukiewicz ◽  
Krzysztof Dudzik
Keyword(s):  
Mechanical Properties ◽  
Acoustic Emission ◽  
Composite Material ◽  
Composite Materials ◽  
Testing Machine ◽  
Measurement Data ◽  
Entropy Method ◽  
Displacement Sensor ◽  
Metric Entropy ◽  
Plastic Phase

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.

Crack tensor-based evaluation of inada granite behavior due to damage under true-triaxial testing condition

2018 ◽  
Vol 106 ◽  
pp. 30-40 ◽  
Author(s):  
Kamran Panaghi ◽  
Aliakbar Golshani ◽  
Minoru Sato ◽  
Takato Takemura ◽  
Manabu Takahashi
Keyword(s):  
Triaxial Testing ◽  
True Triaxial ◽  
Testing Condition

A True Triaxial Testing Cell

2009 ◽  
pp. 819-819-15 ◽  
Author(s):  
V Silvestri ◽  
RN Yong ◽  
AMO Mohamed
Keyword(s):  
Triaxial Testing ◽  
True Triaxial

A New Design of Triaxial Test Chamber with Temperature and Pressure for Deep Rock

2011 ◽  
Vol 422 ◽  
pp. 734-738
Author(s):  
Yong Yan Wang ◽  
Nan Qin ◽  
Jian Guang Li ◽  
Ying Li
Keyword(s):  
Testing Machine ◽  
Test Chamber ◽  
Test System ◽  
Axial Displacement ◽  
Cylinder Wall ◽  
Element Analysis ◽  
Deep Rock ◽  
Triaxial Testing Machine ◽  
Temperature And Pressure ◽  
Embedded Type

According to the research of existing triaxial testing machine of deep rock, a new test chamber with temperature-hold and pressure-tight is developed.The features of test box are as follows: a new kind of axial displacement test system with outer embedded type is designed for measuring the axial displacement of samples correctly; the circuit of oiling system is used to keep temperature and pressure; it’s convenient to take down the test box from the machine and the other functions of testing machine are not affected. So the availability factor of instrument can be improved. Finally, the thickness of cylinder wall is calculated, and according to the modeling and finite element analysis based on ANSYS, the results show that the cylinder can meet the working requirement.

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