Investigation of acoustic emission accompanying stick-slip movement of rock samples at different stiffnesses of spring–block system

2011 ◽  
Vol 44 (7-8) ◽  
pp. 811-819 ◽  
Author(s):  
Teimuraz Matcharashvili ◽  
Tamaz Chelidze ◽  
Natalia Zhukova ◽  
Ekaterine Mepharidze
Keyword(s):  
Acoustic Emission ◽  
Stick Slip ◽  
Rock Samples ◽  
Block System

Influence of the Structure of a Gouge-Filled Fault on the Parameters of Acoustic Emission

2019 ◽  
Vol 105 (5) ◽  
pp. 759-765 ◽  
Author(s):  
Alexey A. Ostapchuk ◽  
Kseniya G. Morozova ◽  
Dmitry V. Pavlov
Keyword(s):  
Acoustic Emission ◽  
Laboratory Experiments ◽  
Shear Crack ◽  
Kinematic Parameters ◽  
Stick Slip ◽  
Omori Law ◽  
Shear Loads ◽  
Initial Stage ◽  
Slip Event ◽  
Model Setup

Presented are the results of laboratory experiments on investigating manifestations of acoustic emission (AE) of a gouge-filled fault during stick-slip. The laboratory experiments were held at the slider-model setup, when a granite block slides along a rough granite base under normal and shear loads. In the course of experiments we altered the structure of the two-component filler of the fault and focused on variations of the AE parameters. The kinematic parameters of fault slip events in all the realizations remained approximately the same. The eff ect of gouge structure on the statistics of AE has been revealed. An alteration of proportion of quartz sand / glass beads in the filler of the fault was accompanied by an alteration of the b-value of frequency-energy distribution from 0.53 to 0.85, and the p-value of Omori law from 1.00 to 2.06. Also, it has been demonstrated that the nucleation of a slip event is accompanied by an alteration of the mechanism of AE generation – at the initial stage the 'tensile crack' signals prevailed, while at the final stage – the 'shear crack' signals did. The alteration of AE genesis manifested vividly in a corresponding alteration of the emitted waveforms for all the realizations.

Seal Lubrication of an Automotive Water Pump

Tribology ◽  
2006 ◽  
Author(s):  
Massimo Antonini ◽  
Rodolfo Faglia ◽  
Carlo Remino ◽  
Marco Pedersoli
Keyword(s):  
Acoustic Emission ◽  
Theoretical Model ◽  
Working Conditions ◽  
Automotive Industry ◽  
Dynamic Instability ◽  
Mechanical Seal ◽  
Water Pump ◽  
Stick Slip ◽  
Grave Problem ◽  
Water Pumps

A noisy mechanical seal is a grave problem, especially in water pumps designed for the automotive industry. The noisiness is often caused by dynamic instability (stick-slip behavior), which occurs when the seal lubrication changes from hydrodynamic to mixed. Starting from this hypothesis, the paper shows a theoretical model that describes the interaction between the seal disks. Therefore this model correlates the acoustic emission to the working conditions of the water pump.

Features of acoustic emission at various influences on rock samples

2008 ◽  
Vol 123 (5) ◽  
pp. 3290-3290 ◽  
Author(s):  
Alexander S. Voznesenskiy ◽  
Sergey V. Viljamov
Keyword(s):  
Acoustic Emission ◽  
Rock Samples

On the stimulation of acoustic emission in rock samples by electromagnetic fields

2011 ◽  
Vol 47 (10) ◽  
pp. 926-936 ◽  
Author(s):  
B. V. Borovskii ◽  
L. M. Bogomolov ◽  
A. S. Zakupin ◽  
V. A. Mubassarova
Keyword(s):  
Acoustic Emission ◽  
Electromagnetic Fields ◽  
Rock Samples ◽  
Stimulation Of

NONLINEAR CHARACTERISTICS OF ACOUSTIC EMISSION DURING THE HEATING PROCESS OF COAL AND ROCK

Fractals ◽  
2018 ◽  
Vol 26 (04) ◽  
pp. 1850046 ◽  
Author(s):  
ZHIBO ZHANG ◽  
ENYUAN WANG ◽  
ENLAI ZHAO ◽  
SHUAI YANG
Keyword(s):  
Acoustic Emission ◽  
Hurst Exponent ◽  
Multifractal Spectrum ◽  
Heating Process ◽  
Nonlinear Characteristics ◽  
Rock Samples ◽  
Spectrum Width ◽  
Multifractal Theory ◽  
Ae Signal ◽  
Temperature Levels

In this paper, acoustic emission (AE) signal of coal and rock samples during the heating process are measured. The results show that AE energy of coal samples is higher than that of rock samples. Based on the multifractal theory, the multifractal characteristics of AE signal are researched. The multifractal spectrum width ([Formula: see text]) of coal samples is wider than that of rock samples, which means AE signal of coal samples is more complex than AE signal of rock samples during the heating process. Multifractal parameter ([Formula: see text]) is more than zero, illustrating that small AE signal is dominate. The time-varying multifractal characteristics are analyzed, and the change trend of multifractal spectrum width ([Formula: see text]) of coal and rock samples is consistent. At the stage of 40–50[Formula: see text]C, multifractal spectrum width ([Formula: see text]) gets the maximum value, whereas multifractal spectrum width ([Formula: see text]) gets the minimum value at the stage of 80–100[Formula: see text]C. For coal samples, multifractal parameter ([Formula: see text] is more than zero except at the stage of 40–50[Formula: see text]C. However, multifractal parameter ([Formula: see text] of rock samples is always more than zero during the entire heating process. By [Formula: see text] analytical method, Hurst exponent of AE signal is calculated. The results show that Hurst exponent of coal and rock samples are more than 0.5, which indicate that AE signal presents persistence, and there is a positive correction between AE signal and temperature. In different temperature levels, Hurst exponent curve presents an increase trend after the initial decrease.

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