scholarly journals Influence of Frequency and Distance on Acoustic Emission Velocity Propagating in Various Dielectrics

2020 ◽  
Vol 10 (9) ◽  
pp. 3305
Author(s):  
Daria Wotzka
Keyword(s):  
Acoustic Emission ◽  
Nonlinear Regression ◽  
Modulation Frequency ◽  
Partial Discharges ◽  
Time Of Arrival ◽  
Dielectric Liquids ◽  
Signal Parameters ◽  
Two Factors ◽  
Ae Signal

The results obtained for the measurements of acoustic emission (AE) signal parameters emitted in three dielectric liquids are presented in this paper. In particular, the velocity of AE wave was calculated based on the time of arrival of the AE signal. A frequency modulated signal was generated by a piezoelectric transducer and measured at various distances by a hydrophone. The changes in velocity values at particular distances and for different frequencies were investigated. The analyses include the determination of the dependency of the velocity values from the distance between the communicating devices. A nonlinear regression model was calculated, and the differences between AE velocities propagating in the considered dielectrics were determined. Similarly, the influence of modulation frequency on the AE velocity was determined using nonlinear regression. Based on the calculation data, it can clearly be stated that the velocity of AE wave depends significantly on the frequency and distance at which it is registered. These two factors may have an important influence on the localization of partial discharges (PD) occurring in these types of dielectric liquids.

Surface Roughness Prediction Based on Acoustic Emission Signals in High-Precision Diamond Turning of Rapidly Solidified Optical Aluminum Grade (RSA443)

2020 ◽  
Vol 841 ◽  
pp. 363-368
Author(s):  
Zvikomborero Hweju ◽  
Khaled Abou-El-Hossein
Keyword(s):  
Surface Roughness ◽  
Acoustic Emission ◽  
Prediction Accuracy ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Surface Roughness Prediction ◽  
Peak Rate ◽  
Signal Parameters ◽  
Roughness Prediction ◽  
Ae Signal

Acoustic emission signal-based prediction of surface roughness has been utilized widely, yet little work has been done in this regard on RSA443. This paper seeks to study the correlation between acoustic emission (AE) signal parameters and surface roughness. Estimation of surface roughness using AE signal parameters and subsequent examination of the influence of AE signal parameters (root mean square, peak rate and prominent frequency) on the accuracy of the RSM model in surface roughness prediction are carried out. The experiment is designed using the Taguchi L9 orthogonal array to minimize the number of experiments. Emitted acoustic signals are captured using a Piezotron sensor. Three RSM models are formulated and compared in this study: a model that uses only critical machining parameters (cutting speed, depth of cut and feed rate), a model that uses only AE signal parameters (root mean square, peak rate and prominent frequency) and a model that uses both critical machining parameters and AE signal parameters. An assessment based on the models’ mean absolute percentage error (MAPE) is made to see if AE signal parameters have any contribution towards surface roughness prediction accuracy. The order of parameter significance in the most accurate model is investigated in this paper. The mean absolute percentage error results for the models indicate that the model in which AE signal parameters are utilized in conjunction with critical machining parameters has the highest prediction accuracy of 97.32%. The model that utilizes only critical machining parameters has a prediction accuracy of 96.35% while the one that utilizes only AE signal parameters has a prediction accuracy of 84.43%. It is observed that the order of parameter significance from the most to the least significant is as follows: feed rate, cutting speed, peak rate, AErms, depth of cut and prominent frequency.

INFLUENCE OF ACOUSTIC-ELECTRONIC CHANNEL ON ACOUSTIC EMISSION HIT PARAMETERS

2020 ◽  
pp. 14-22
Author(s):  
A. A. Sazonov ◽  
V. I. Shelobkov ◽  
V. I. Ivanov
Keyword(s):  
Acoustic Emission ◽  
Significant Influence ◽  
Signal Propagation ◽  
Propagation Channel ◽  
Object State ◽  
Signal Parameters ◽  
Ae Signal ◽  
Electronic Channel ◽  
Ae Signals ◽  
Electronic Channels

The paper deals with the influence of acoustic emission (AE) signal propagation channel on the parameters of these signals, which are used to judge the object state. It is shown that the acoustic channel, which includes the testing object and the acoustic emission transducer, has a significant influence on the parameters of AE signals. This must be taken into account, both in the interpretation of signals and in the calibration of acoustic emission transducers. Specific examples of degradation of AE signal parameters during the passage of acoustic-electronic channels are shown.

scholarly journals Influence of additional dielectric coatings on the electrode surfaces on selected parameters of acoustic emission signals in high-voltage gas insulation systems

2021 ◽  
Author(s):  
Arkadiusz Dobrzycki ◽  
Władysław Opydo ◽  
Sebastian Zakrzewski
Keyword(s):  
Acoustic Emission ◽  
High Voltage ◽  
Single Pulse ◽  
Partial Discharges ◽  
Chamber Pressure ◽  
Electrode Surfaces ◽  
Dielectric Coatings ◽  
Signal Parameters ◽  
Insulation Systems ◽  
High Voltage Insulation

AbstractThe paper is devoted to the study of impact of additional dielectric coatings placed on the surface of the electrodes on the operation of a high-voltage insulation system with air as insulating medium. The study mainly focused on measurement of partial discharges (PDs) with the use of acoustic emission method. Tests were conducted in various levels of chamber pressure. Applicable parameters of recorded signals were analyzed with the use of applications developed in the environment of MATLAB software. The results of analyses clearly show that presence of additional coatings has impact on signal parameters and thus indirectly on PDs. The use of coatings reduces the duration of a single pulse (event) and increases its amplitude. Furthermore, the influence of degradation of the coating caused by individual discharges on the values of the analyzed parameters was analyzed. The study has shown, however, that this effect is negligible.

scholarly journals Determination of the distortions introduced by the compression algorithm in the results of the measurement of the local impact control device “Prognoz-L”.

2018 ◽  
Vol 56 ◽  
pp. 02016
Author(s):  
Dmitry Migunov ◽  
Alexey Grunin
Keyword(s):  
Acoustic Emission ◽  
Control Device ◽  
Compression Algorithm ◽  
Statistical Characteristics ◽  
Pressure Monitoring ◽  
Rockburst Hazard ◽  
Automatic Mode ◽  
Signal Parameters ◽  
Local Impact

The article discusses the application of the u-law algorithm from the G.711 standard, which performs lossy compression. A theoretical error introduced by this algorithm into discrete samples of digitized acoustic emission signals is determined. The effect of compression on signal parameters was also determined. During the analysis, the data from the local "Prognoz-L" device were used. "Prognoz-L" performs rockburst hazard assessment. The data were processed in an automatic mode to isolate pulsed signals containing acoustic emission. The processing of the obtained sample of pulse signals made it possible to determine the basic statistical characteristics of the errors introduced by the compression algorithm into the values of the signal parameters. The possibility of using this algorithm for preliminary processing of acoustic emission signals is established with the aim of keeping rock pressure monitoring in low-power acoustic-emission devices.

A Review on the Relationships Between Acoustic Emission, Friction and Wear in Mechanical Systems

2019 ◽  
Vol 72 (2) ◽  
Author(s):  
Peipei Feng ◽  
Pietro Borghesani ◽  
Wade A. Smith ◽  
Robert B. Randall ◽  
Zhongxiao Peng
Keyword(s):  
Acoustic Emission ◽  
Condition Monitoring ◽  
Friction And Wear ◽  
Theoretical Models ◽  
Experimental Investigations ◽  
Two Factors ◽  
Specific Contact ◽  
Comprehensive Picture ◽  
Ae Signal ◽  
The Impact

Abstract Acoustic emission (AE) techniques play a key role in machine condition monitoring and wear/fault diagnosis. Understanding the impact of friction and wear on the generation of AE signals is essential to building a reliable wear monitoring system. However, existing papers focus on only one or two factors in specific contact conditions. This paper aims at surveying studies related to both theoretical models and experimental investigations to produce a comprehensive picture of the relationship between tribological parameters (e.g., surface roughness, oil film thickness, and friction coefficient), operating parameters (e.g., sliding velocity and load), and AE signal characteristics (e.g., amplitude/energy, frequency, and event count). This result will provide guidance for the development of AE-based condition monitoring approaches and in particular for the establishment of AE-based wear assessment techniques.

A strategy to locate partial discharges in power transformers using acoustic emission

2007 ◽  
Vol 1 (05) ◽  
pp. 596-600 ◽  
Author(s):  
Giscard Franceire Cintra Veloso ◽  
◽  
Luiz Eduardo Borges da Silva ◽  
Germano Lambert-Torres
Keyword(s):  
Acoustic Emission ◽  
Partial Discharges ◽  
Power Transformers

The influence of ultrasound signal parameters on sonoluminescence light intensity

2013 ◽  
Vol 62 (4) ◽  
pp. 605-612
Author(s):  
Marek Szmechta ◽  
Tomasz Boczar ◽  
Dariusz Zmarzły
Keyword(s):  
Acoustic Emission ◽  
Acoustic Waves ◽  
Power Transformer ◽  
Electrical Power ◽  
Partial Discharges ◽  
Research Project ◽  
Insulation Systems ◽  
Secondary Phenomenon ◽  
New Research ◽  
The Relationship

Abstract Topics of this article concern the study of the fundamental nature of the sonoluminescence phenomenon occurring in liquids. At the Institute of Electrical Power Engineering at Opole University of Technology the interest in that phenomenon known as secondary phenomenon of cavitation caused by ultrasound became the genesis of a research project concerning acoustic cavitation in mineral insulation oils in which a number of additional experiments performed in the laboratory aimed to determine the influence of a number of acoustic parameters on the process of the studied phenomenona. The main purpose of scientific research subject undertaken was to determine the relationship between the generation of partial discharges in high-voltage power transformer insulation systems, the issue of gas bubbles in transformer oils and the generated acoustic emission signals. It should be noted that currently in the standard approach, the phenomenon of generation of acoustic waves accompanying the occurrence of partial discharges is generally treated as a secondary phenomenon, but it can also be a source of many other related phenomena. Based on our review of the literature data on those referred subjects taken, it must be noted, that this problem has not been clearly resolved, and the description of the relationship between these phenomena is still an open question. This study doesn’t prove all in line with the objective of the study, but can be an inspiration for new research project in the future in this topic. Solution of this problem could be a step forward in the diagnostics of insulation systems for electrical power devices based on non-invasive acoustic emission method.

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