scholarly journals Experimental Investigation on Effective Distances of Acoustic Emission in Concrete Structures

2020 ◽  
Vol 10 (17) ◽  
pp. 6051 ◽  
Author(s):  
Tae-Min Oh ◽  
Min-Koan Kim ◽  
Jong-Won Lee ◽  
Hyunwoo Kim ◽  
Min-Jun Kim
Keyword(s):  
Acoustic Emission ◽  
Impact Energy ◽  
Concrete Structures ◽  
Propagation Distance ◽  
Monitoring Systems ◽  
Effective Distance ◽  
Destructive Testing ◽  
Length Width ◽  
Ae Signal ◽  
The Impact

As one of the non-destructive testing (NDT) methods, acoustic emission (AE) can be widely applied to the field of engineering and applied science owing to its advantageous characteristics. In particular, the AE method is effectively applied to monitor concrete structures in civil engineering. For this technology to be employed in a monitoring system, it is necessary to investigate the propagation characteristics of the AE in structures. Hence, this study investigates the characteristics of AE in concrete structures to evaluate the field applicability of AE monitoring systems. To achieve this goal, experiments employing an AE system are conducted for concrete structures 20 × 0.2 × 1.2 m in length, width, and height, respectively, to explore the AE parameters according to the impact energy. Among all AE parameters, absolute energy is determined to be most sensitive factor with respect to the impact energy. In addition, the attenuation effect of the AE wave is quantitatively evaluated according to the wave propagation distance. Moreover, the concept of effective distance is newly suggested based on the experimental results. The effective distance is shown to increase as the impact energy increases, although the increased effective distance is limited because the damaged AE signal is of high frequency. This study helps improve the field applicability of AE monitoring systems by suggesting suitable AE sensor spacing, which contributes to promote the practice of technology.

RELATIONSHIP BETWEEN AE SIGNAL STRENGTH AND ABSOLUTE ENERGY IN DETERMINING DAMAGE CLASSIFICATION OF CONCRETE STRUCTURES

2016 ◽  
Vol 78 (5) ◽  
Author(s):  
Shahiron Shahidan ◽  
Siti Radziah Abdullah ◽  
Isham Ismail
Keyword(s):  
Acoustic Emission ◽  
Monitoring System ◽  
Concrete Structures ◽  
Signal Strength ◽  
Load Test ◽  
Bending Test ◽  
Damage Classification ◽  
Four Point Bending ◽  
Ae Signal ◽  
Absolute Energy

The most efficient tools in real monitoring system is acoustic emission (AE). This technique can be used to identify the damage classifications in RC structure. This research paper will mainly focus on the utilization of signal strength and Absolute energy (AE signal) in determining on the damage quantification for RC beam subjected to cyclic load test. The beam specimens size (150 X 250 X 1900) mm were prepared in the laboratory and tested with the four point bending test using cyclic loading together with acoustic emission monitoring system. The results showed that the analysis of AE data parameters is capable of determining the damage classification in concrete structures and the data corresponded to the visual observations during the increased loading cycle.

Acoustic Emission (AE) Propagation Attenuation Theory and Rule in Non-Perfect Elastic Coal and Rock

2013 ◽  
Vol 477-478 ◽  
pp. 620-623
Author(s):  
Guo Wei Dong
Keyword(s):  
Numerical Simulation ◽  
Acoustic Emission ◽  
Quality Factor ◽  
Field Test ◽  
Propagation Distance ◽  
Signal Propagation ◽  
Emission Signal ◽  
Ae Signal ◽  
Propagation Rule ◽  
Quality Factor Q

Propagation rule of acoustic emission (AE) signal in coal and rock is an important basis when AE technique forecasts coal and rock dynamical disasters. Based on correlative theory of quality factor Q, Acoustic emission signal propagation attenuation formula in non-perfect elastic coal and rock are analyzed, Based on the theoretic formula, Effects of different quality factor and propagation distance on AE propagation attenuation are theoretically analyzed ;Based on theoretic analysis results, AE signal propagation numerical simulation and field test programs are designed, AE signal propagation rules in elastoplastic coal and rock are obtained. Field test and numerical simulation experimentation results validate rationality of theoretic forumla. Study production can guide AE technique that forecasts mine and rock dynamical disasters.

scholarly journals A Time-Frequency Based Approach for Acoustic Emission Assessment of Sliding Wear

Lubricants ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 52
Author(s):  
Igor Rastegaev ◽  
Dmitry Merson ◽  
Inna Rastegaeva ◽  
Alexei Vinogradov
Keyword(s):  
Acoustic Emission ◽  
Sliding Friction ◽  
Monitoring And Control ◽  
Destructive Testing ◽  
Noise Sources ◽  
Processing Technologies ◽  
Time Frequency ◽  
On Line ◽  
Ae Signal ◽  
And Control

The acoustic emission method is one of few contemporary non-destructive testing techniques enabling continuous on-line health monitoring and control of tribological systems. However, the existence of multiple “pseudo”-acoustic emission (AE) and noise sources during friction, and their random occurrence poses serious challenges for researchers and practitioners when extracting “useful” information from the upcoming AE signal. These challenges and numerous uncertainties in signal classification prevent the unequivocal interpretation of results and hinder wider uptake of the AE technique despite its apparent advantages. Currently, the signal recording and processing technologies are booming, and new applications are born on this support. Specific tribology applications, therefore, call for developing new and tuning existing approaches to the online AE monitoring and analysis. In the present work, we critically analyze, compare and summarize the results of the application of several filtering techniques and AE signal classifiers in model tribological sliding friction systems allowing for the simulation of predominant wear mechanisms. Several effective schemes of AE data processing were identified through extensive comparative studies. Guidelines were provided for practical application, including the online monitoring and control of the systems with friction, characterizing the severity and timing of damage, on-line evaluation of wear as sliding contact tests and instrumented acceleration of tribological testing and cost reduction.

scholarly journals Visualization of the Coated Electrode Welding

2016 ◽  
Vol 64 (1) ◽  
pp. 43-51
Author(s):  
Michal Černý ◽  
Petr Dostál ◽  
Michal Šustr
Keyword(s):  
Acoustic Emission ◽  
Chemical Composition ◽  
Welding Process ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Mechanical Verification ◽  
Joint Formation ◽  
Coated Electrode ◽  
The Impact ◽  
Non Destructive

This work is dedicated to the evaluation of the welding process in terms of assessing the impact of weldability based on the recording of the non-destructive testing of the acoustic emission (AE). Measurements are performed utilising both materials with guaranteed weldability and materials with reduced weldability. In addition to welding, the thesis also discusses the material (metallographic and fractographic) and mechanical verification of joint formation and the variations in behaviour of metals of differing chemical composition. It also includes an analysis of AE records in relation to the condition of the material during the developing of fusion and resistance joints.

scholarly journals Failure mechanism and acoustic emission signal characteristics of coatings under the condition of impact indentation

2019 ◽  
Vol 38 (2019) ◽  
pp. 601-611
Author(s):  
Dong Tian-Shun ◽  
Wang Ran ◽  
Li Guo-Lu ◽  
Liu Ming
Keyword(s):  
Acoustic Emission ◽  
Surface Morphology ◽  
Failure Mechanism ◽  
Bonding Strength ◽  
Cross Sectional ◽  
Emission Signal ◽  
Signal Characteristics ◽  
Interface Cracking ◽  
Ae Signal ◽  
The Impact

AbstractIn this work, the substrate, NiCr coating, Al2O3 coating with NiCr undercoating and Al2O3 coating were tested by an impact indentation device equipped with an acoustic emission (AE) detection equipment. The surface morphology, dimension, cross-sectional image, 3D topography of indention and bonding strength of coatings were analyzed. The failure mechanism and AE signal characteristics of the coatings under impact were studied. The results demonstrate that the failure mode of NiCr coating was dominated by interface cracking, and that of Al2O3 coating is fracture and accompanied by a small amount of interface cracking, while Al2O3 coating with NiCr undercoating possesses common characteristics of the first two. The energy counting and wave voltage of AE signal were more sensitive to the bonding strength of coating in the impact process, which can be used to characterize the bonding strength of coating.

Acoustic Emission Attenuation and Source Location of Resin Matrix for Wind Turbine Blade Composites

2014 ◽  
Vol 912-914 ◽  
pp. 36-39 ◽  
Author(s):  
Yan Rong Pang ◽  
Zhi Hui Lv ◽  
Xiao Min Liang ◽  
Han Chang Chai ◽  
Ruo Chen Liu ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Source Location ◽  
Wind Turbine Blade ◽  
Resin Matrix ◽  
Destructive Testing ◽  
Testing Technology ◽  
Ae Signal ◽  
The One

In recent years, acoustic emission (AE) testing technology is the one of the most important non-destructive testing (NDT) methods. The characteristics can be described by AE signals, including the location, nature and severity. In order to obtain the basic data for monitoring the wind turbine blade composite structure, the experiment adopted Φ0.5 mm lead pencil as artificial acoustic emission source and measured AE parameters, attenuation and source location of resin matrix for wind turbine blade. This paper introduced linear location and two-dimensional positioning technology of time arrival location method about the burst AE signal. The result shows that the location of AE source basically reflects the location of stimulation AE source, the location of AE source for resin matrix can agree well with the simulated location of AE source, the more close to the middle area, the more accurate location.

scholarly journals Study on the frequency of acoustic emission signal during crystal growth of salicylic acid

2021 ◽  
Vol 10 (1) ◽  
pp. 596-604
Author(s):  
Xingjun Wang ◽  
Quanmin Xie ◽  
Ying Huang
Keyword(s):  
Particle Size ◽  
Acoustic Emission ◽  
Salicylic Acid ◽  
Vibration Frequency ◽  
Diffusion Theory ◽  
Elastic Vibration ◽  
Growth Unit ◽  
Time Frequency ◽  
Ae Signal ◽  
The Impact

Abstract Based on the results of the previous experiment, this article studied the acoustic emission (AE) signals released during the crystallization of salicylic acid to establish the relationship between the AE signal and the particle size. A tremendous amount of acoustic data was analyzed using time–frequency domain analysis methods in order to extract the valuable contents. Based on the diffusion theory, the vibratory model between the AE signal and the crystal particle size was established. This article mainly studies the process of small particles diffusing to the growth point by impact, adding to the lattice, and the crystal releases energy. The impact of the growth unit on particle aggregate is equivalent to a linear elastic vibration system with one end fixed and the other end free. The vibration frequency is 200–355 kHz when the particle size is between 600 and 1,100 µm. The calculated vibration frequency is in good agreement with the measured frequency.

scholarly journals Acoustic Emission-Based Condition Monitoring and Remaining Useful Life Prediction of Hydraulic Cylinder Rod Seals

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6012
Author(s):  
Jørgen F. Pedersen ◽  
Rune Schlanbusch ◽  
Thomas J. J. Meyer ◽  
Leo W. Caspers ◽  
Vignesh V. Shanbhag
Keyword(s):  
Acoustic Emission ◽  
Condition Monitoring ◽  
Hydraulic Cylinder ◽  
Remaining Useful Life ◽  
Test Rig ◽  
Operational Conditions ◽  
Hydraulic Cylinders ◽  
Ae Signal ◽  
Useful Life ◽  
The Impact

The foremost reason for unscheduled maintenance of hydraulic cylinders in industry is caused by wear of the hydraulic seals. Therefore, condition monitoring and subsequent estimation of remaining useful life (RUL) methods are highly sought after by the maintenance professionals. This study aimed at investigating the use of acoustic emission (AE) sensors to identify the early stages of external leakage initiation in hydraulic cylinders through run to failure studies (RTF) in a test rig. In this study, the impact of sensor location and rod speeds on the AE signal were investigated using both time- and frequency-based features. Furthermore, a frequency domain analysis was conducted to investigate the power spectral density (PSD) of the AE signal. An accelerated leakage initiation process was performed by creating longitudinal scratches on the piston rod. In addition, the effect on the AE signal from pausing the test rig for a prolonged duration during the RTF tests was investigated. From the extracted features of the AE signal, the root mean square (RMS) feature was observed to be a potent condition indicator (CI) to understand the leakage initiation. In this study, the AE signal showed a large drop in the RMS value caused by the pause in the RTF test operations. However, the RMS value at leakage initiation is seen to be a promising CI because it appears to be linearly scalable to operational conditions such as pressure and speed, with good accuracy, for predicting the leakage threshold.

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