Observations of premonitory acoustic emission and slip nucleation during a stick slip experiment in smooth faulted Westerly granite

2005 ◽  
Vol 32 (10) ◽  
Author(s):  
Ben D. Thompson
Keyword(s):  
Acoustic Emission ◽  
Stick Slip

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.

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

scholarly journals Off-fault damage and acoustic emission distributions during the evolution of structurally complex faults over series of stick-slip events

2014 ◽  
Vol 197 (3) ◽  
pp. 1705-1718 ◽  
Author(s):  
T. H. W. Goebel ◽  
T. W. Becker ◽  
C. G. Sammis ◽  
G. Dresen ◽  
D. Schorlemmer
Keyword(s):  
Acoustic Emission ◽  
Stick Slip

scholarly journals Analysis of energy characteristics of acoustic emission signals during uniaxial compression of geomaterial samples

2020 ◽  
Vol 196 ◽  
pp. 02004
Author(s):  
Vladimir Sychev ◽  
Leonid Bogomolov ◽  
Dmitriy Kulkov
Keyword(s):  
Acoustic Emission ◽  
Energy Distribution ◽  
Uniaxial Compression ◽  
Sampling Rate ◽  
Maximum Amplitude ◽  
Low Noise ◽  
Distribution Functions ◽  
Stick Slip ◽  
Ae Signal ◽  
Ae Signals

Acoustic emission (AE) signals were obtained during deformation by uniaxial compression of specimens of various geomaterials. Experiments on uniaxial compression were carried out on a low-noise lever setup with water leakage, where the maximum load on the sample does not exceed 250 kN. The received signals were digitized by an 8-channel USB 3000 ADC unit with a width of 14 bits and a maximum sampling rate of 3 MHz. The energy distribution functions of AE signals are considered. The maximum amplitude of the AE waveform was selected as the energy characteristic of the AE signal. The flow of AE events is considered from the viewpoint of nonequilibrium thermodynamics using the Tsallis statistics. To describe the energy distribution function of the AE signals, we used a modified model of a stick-slip earthquake source -”discontinuous sliding” of two plates over each other along a fault in the presence of friction and the principle of maximum entropy. The model is used to quantify long-range correlations arising in the flow of earthquakes. It is shown that the AE signal flow is a system with memory and longrange correlations. The analysis of the behavior of the Tsallis parameter was carried out throughout the experiment.

Study on Stick–Slip Friction of Reciprocating O-Ring Seals Using Acoustic Emission Techniques

2012 ◽  
Vol 55 (1) ◽  
pp. 43-51 ◽  
Author(s):  
Chuanjun Liao ◽  
Shuangfu Suo ◽  
Yuming Wang ◽  
Weifeng Huang ◽  
Ying Liu
Keyword(s):  
Acoustic Emission ◽  
Stick Slip

scholarly journals Effects of Particle Size on Fault Gouge Frictional Characteristics and Associated Acoustic Emission

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yang Liu ◽  
Cai-Ping Lu ◽  
Tong-bin Zhao ◽  
Heng Zhang
Keyword(s):  
Particle Size ◽  
Acoustic Emission ◽  
Surface Defects ◽  
Dynamic Instability ◽  
Shear Velocity ◽  
Fault Gouge ◽  
Stick Slip ◽  
Compaction Rate ◽  
Fault Strength ◽  
Stable Sliding

Our experimental work was designed to explore the particle size effect of simulated fault gouge on slip characteristics by the conventional double-direct shear friction configuration combined with acoustic emission (AE). The following conclusions were drawn: (1) smaller particles allow for an initially higher compaction rate at a higher speed and longer duration for force chain formation and destruction. The larger the particle size is, the higher the slipping displacement rate is; (2) the smaller the particle size is, the larger the friction coefficient is, and thus the higher the fault strength is. In addition, the larger the shear velocity is, the higher the fault strength is; (3) the smaller the particle size is, the higher the shear stress drop generated by the stick-slip is, and the stronger the dynamic slip intensity for a stick-slip period is; and (4) surface defects of forcing blocks possibly help to embed foregoing “stability” and “stable sliding” into the normal stick-slip stage. Especially, the “stable sliding” is possibly related to formation of stubborn force chains. These findings may shed some insights into further clarification of slipping characteristics and discrimination of precursory signs of fault dynamic instability with different-sized gouge particles.

Irregular stick-slip and the role of cohesion in an ice friction experiment

2021 ◽  
Author(s):  
Evangelos Korkolis ◽  
Florent Gimbert ◽  
Jérôme Weiss ◽  
François Renard
Keyword(s):  
Acoustic Emission ◽  
High Speed ◽  
Water Tank ◽  
Sliding Velocity ◽  
Sampling System ◽  
Stick Slip ◽  
Fault Strength ◽  
Asymmetric Shape ◽  
Frictional Interface ◽  
Fault Gouges

<p>Understanding the evolution of fault strength over multiple interseismic periods is crucial to quantifying seismic hazard. According to Coulomb’s failure criterion, restrengthening, or healing, may result from an increase in friction and/or in cohesion. Classic sliding experiments on rocks and fault gouges are not able to resolve the contribution of cohesion to the healing of frictional interfaces. Here, we present a zero nominal normal stress friction experiment capable of large displacements that exhibits similar complexity as the deforming lithosphere (intermittent, aperiodic deformation; Gutenberg-Richter-type scaling of event sizes). This Couette-type apparatus is designed to shear millimeter-thick layers of columnar ice, grown in-situ in a meter scale circular water tank. When the system is driven at low sliding velocities, the ice plate fractures and sliding occurs along a complex, non-prescribed frictional interface. Water beneath the ice can percolate through the sliding interface and freeze, increasing its strength. A torque gauge and an array of acoustic emission transducers are used to measure the shear strength of the frictional interface and to monitor acoustic activity. Previous work, using constant values of sliding velocity, showed that deformation occurs via a combination of slow and fast slip events, and that the “seismic” part consists of two populations of acoustic emission (AE) events: standalone and correlated, with different Gutenberg-Richter b-values. The asymmetric shape of the shear stress (torque) fluctuations was attributed to cohesion-dominated strength recovery. We are currently using a new, high speed sampling system to investigate the relationship between the stress fluctuations and the concurrent AE activity in constant as well as variable sliding velocity experiments. This work aims to evaluate the effect of time-dependent processes on systems that deform intermittently.</p>

INVESTIGATION OF MECHANICAL DAMPING CHARACTERISTIC IN SHORT FIBERGLASS REINFORCED POLYCARBONATE COMPOSITES

2013 ◽  
Vol 27 (15) ◽  
pp. 1350108 ◽  
Author(s):  
MYOUNG-RAE CHO ◽  
HYUNG-ICK KIM ◽  
JAE-SOON JANG ◽  
JONGHWAN SUHR ◽  
DEVIN R. PRATE ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Composite Materials ◽  
Polymer Composites ◽  
Tensile Testing ◽  
Damping Properties ◽  
Cyclic Testing ◽  
Acoustic Emission Technique ◽  
Stick Slip ◽  
Reinforced Polymer

The focus of this study is to experimentally investigate the effect of debonding stress, the interface between the fibers and the polymer matrix, on the damping properties of the short fiberglass reinforced polymer composites. In this study, short fiberglass reinforced polycarbonate composite materials were fabricated and characterized for their tensile properties by varying the fiberglass loading fraction. The debonding stress was evaluated by coupling the acoustic emission technique with the tensile testing. After the determination of the debonding stress was completed, dynamic cyclic testing was performed in order to investigate the effect of debonding on the damping properties of the polymer composites. It was experimentally observed in this study that the debonding can facilitate the stick-slip friction under cyclic loadings, which then gives rise to better damping performance in the fiberglass composites.

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