Characterisation of Partial Melting and Solidification of Granite E93/7 by the Acoustic Emission Technique

2008 ◽  
Vol 1107 ◽  
Author(s):  
Lyubka M. Spasova ◽  
Fergus G.F. Gibb ◽  
Michael I. Ojovan
Keyword(s):  
Acoustic Emission ◽  
Phase Transformations ◽  
Partial Melting ◽  
Frequency Spectrum ◽  
Stress Waves ◽  
Radioactive Wastes ◽  
Deep Borehole ◽  
Acoustic Emission Technique ◽  
Ae Signals ◽  
Melting And Solidification

AbstractThe acoustic emission (AE) technique was used to detect and characterise the processes associated with generation of stress waves during melting and solidification of granite E93/7 at a pressure of 0.15 GPa. The AE signals recorded as a result of partial melting of the granite at a temperature of 780°C and subsequent solidification during cooling were distinguished from the equipment noise and their parameters used to characterise the AE sources associated with the phase transformations during melting and solidification of the granite. The mechanisms generating AE during granite melting were differentiated by AE signals with their highest peaks in the frequency spectrum at 170 and 268 kHz. The transformation of the liquid into glass during solidification of the partially melted granite generated AE waves in an essentially broad range of frequencies between 100 and 300 kHz. This preliminary work demonstrates the potential of the AE technique for use in applications related to deep borehole disposal of radioactive wastes.

Determining the feasibility of identifying creep rupture of stainless steel cladding tubes on-line using acoustic emission technique

2015 ◽  
Vol 6 (3) ◽  
pp. 410-418
Author(s):  
N Mahendra Prabhu ◽  
K.A. Gopal ◽  
S. Murugan ◽  
T.K. Haneef ◽  
C. K. Mukhopadhyay ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Creep Rupture ◽  
Acoustic Emission Technique ◽  
Content Type ◽  
Fuel Pin ◽  
On Line ◽  
Clad Tube ◽  
Non Destructive ◽  
Ae Signals

Purpose – The purpose of this paper is to determine the feasibility of identifying the creep rupture of reactor cladding tubes using acoustic emission technique (AET). Design/methodology/approach – The creep rupture tests were carried out by pressuring stainless steel capsules upto 6 MPa at room temperature and then heating continuously in a furnace upto rupture. The acoustic emission (AE) signals generated during the creep rupture tests were recorded using a 150 kHz resonant sensor and analysed using AE Win software. Findings – When rupture occurs in the pressurized capsule tube representing the cladding tube, AE sensor attached to a waveguide captures the mechanical disturbance from the capsule and these data can be advantageously used to identify the creep rupture event of the cladding tube. Practical implications – The creep rupture data of fuel clad tube is very important in design and for smooth operation of nuclear reactors without fuel pin failure in reactors. Originality/value – AE is an advanced non-destructive evaluation technique. This technique has been successfully applied for on-line monitoring of creep rupture of the reactor cladding tube which otherwise could be detected by thermocouple readings only.

Design and Experiment of Electromagnetically Induced Acoustic Emission for Metal Crack Detection

2011 ◽  
Vol 291-294 ◽  
pp. 1278-1283
Author(s):  
Chuang Zhang ◽  
Su Zhen Liu ◽  
Qing Xin Yang ◽  
Liang Jin ◽  
Yu Huai Kan
Keyword(s):  
Acoustic Emission ◽  
Theoretical Analysis ◽  
Crack Detection ◽  
Pulse Current ◽  
Engineering Application ◽  
Stress Waves ◽  
Current Generator ◽  
Acoustic Emission Technique ◽  
Expected Effect ◽  
Large Pulse

A new electromagnetically induced acoustic emission technique (EMAE) is presented in this paper. It does nondestructive detection with the effect of dynamic electromagnetic loading to generate a stress field stimulating stress waves from the defects. Theoretical analysis and experiment of the EMAE is carried out. The large pulse current generator which is used in electromagnetically induced acoustic emission (EMAE) is designed based on the energy storage of the capacitor. Applying to the EMAE experiment, it can achieve the expected effect and locate the defect in the aluminium plate. This work laid a good foundation for the engineering application of EMAE.

scholarly journals Nondestructive Detection of Valves Using Acoustic Emission Technique

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jin Yan ◽  
Yang Heng-hu ◽  
Yang Hong ◽  
Zhang Feng ◽  
Liu Zhen ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Condition Monitoring ◽  
Detection System ◽  
Theoretical Models ◽  
Acoustic Emission Technique ◽  
Nondestructive Detection ◽  
Basic Composition ◽  
Measuring Devices ◽  
Cavitation Detection ◽  
Ae Signals

The applications of acoustic emission (AE) technique in detection of valves are presented in this review, and the theoretical models and experimental results of nondestructive detection of valves using AE are provided. The generation of AE signals and the basic composition of AE detection system are briefly explained. The applications of AE technique in valves are focused on condition monitoring, failure, cavitation detection, and the development of portable measuring devices. All results prove that the AE technique works well in the detection of valves.

scholarly journals Flexural Characteristics Evaluation for Reinforced Concrete Affected by Steel Corrosion Based on an Acoustic Emission Technique

2019 ◽  
Vol 9 (8) ◽  
pp. 1640 ◽  
Author(s):  
Zhang ◽  
Tan ◽  
Wang ◽  
Cheng ◽  
Yang ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Failure Modes ◽  
Steel Corrosion ◽  
Test Method ◽  
Rc Beam ◽  
Acoustic Emission Technique ◽  
Statistical Parameters ◽  
Dense Distribution ◽  
Ae Signals

The purpose of this research is to utilize a more advanced test method for investigating the effect of steel corrosion on the flexural characteristics of a reinforced concrete (RC) beam on a microscopic cracking level. Firstly, over-reinforced RC beam specimens were prepared and corroded using an electrical accelerated steel corrosion setup in different ratios. Subsequently, bending and acoustic emission (AE) tests were performed on all the specimens to obtain their ultimate flexural loads, failure modes and AE signals. Furthermore, rise time/peak amplitude (R/A), ringing counts/duration (AF) and improved b (Ib) values, as the statistical parameters of AE signals, were calculated for indicating the transformation of RC specimens’ crack modes and failure modes under the effect of steel corrosion. Finally, the locations of AE events were obtained by localization technology and compared with the locations of concrete cracks (cracks map). The results revealed that the ultimate flexural load decreases with steel corrosion. The crack tends to transform from shear- to tensile-type along with the increase of the steel corrosion ratio. The trend of the Ib-value curve can reflect the formation and development of cracks; and the larger the duration of violent fluctuations in the Ib-value curve is, the larger the ultimate flexural load of the RC beam is. The region where the crack is located can be judged by the position where the relatively dense distribution of the AE events is.

Using Acoustic Emission Technique to Detect Termite Activities in Wood: Laboratory Experiment

2019 ◽  
Vol 69 (1) ◽  
pp. 17-25
Author(s):  
Ahmed El-Hadad ◽  
Graham Ian Brodie
Keyword(s):  
Acoustic Emission ◽  
Laboratory Experiment ◽  
Background Noise ◽  
Acoustic Emissions ◽  
Sound Recording ◽  
Acoustic Emission Technique ◽  
Good Outcome ◽  
Wooden Block ◽  
Ae Signals ◽  
Software Corporation

Abstract This experiment studied and analyzed termite activities in wooden blocks. The purpose of the study was to develop and test a strategy for isolating termite acoustic emissions (AE) from background noise. This task is not trivial, and therefore the achievement of a clean signal that can be directly associated with termite activities is a good outcome. It is an important step toward achieving an accurate, nondestructive system to detect termite activities in wood. The wooden blocks were immersed in jars that were filled with termites to expose the blocks to termite infestation. The termites' AE, due to their activity in the wood, was recorded using microphones that were fitted in the center of each wooden block. The Cool Edit Pro 2.1 (Syntrillium Software Corporation) sound recording application was used to filter the recorded AE signals. The filtered AE signals were then analyzed using the Matlab application. The wooden blocks experiment showed that termite activities in the wood could be detected using AE recording. Termite activities are clear and detectable in the 4.5- to 5-kHz range of frequencies. Results could also assist in defining the termites' AE signature, to some extent, by analyzing the generated sound due to termite activities in the wood. A clean termite-related AE was successfully extracted from the general AE in the wooden blocks using Matlab R2015a tools.

Optimizing the Acoustic-Emission Technique for Examining the Strength of Welded Joints

Vestnik MEI ◽  
2017 ◽  
pp. 96-101
Author(s):  
Viktor V. Nosov ◽  
◽  
Alsu R. Yamilova ◽  
Nikolay A. Zelenskiy ◽  
Ilya V. Matviyan ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Welded Joints ◽  
Acoustic Emission Technique

scholarly journals Analysis of Acoustic Emission (AE) Signals for Quality Monitoring of Laser Lap Microwelding

2021 ◽  
Vol 11 (15) ◽  
pp. 7045
Author(s):  
Ming-Chyuan Lu ◽  
Shean-Juinn Chiou ◽  
Bo-Si Kuo ◽  
Ming-Zong Chen
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Frequency Domain ◽  
Monitoring System ◽  
Welding Quality ◽  
Steel Sheets ◽  
Signal Features ◽  
Ae Signal ◽  
Laser Microwelding ◽  
Ae Signals

In this study, the correlation between welding quality and features of acoustic emission (AE) signals collected during laser microwelding of stainless-steel sheets was analyzed. The performance of selected AE features for detecting low joint bonding strength was tested using a developed monitoring system. To obtain the AE signal for analysis and develop the monitoring system, lap welding experiments were conducted on a laser microwelding platform with an attached AE sensor. A gap between the two layers of stainless-steel sheets was simulated using clamp force, a pressing bar, and a thin piece of paper. After the collection of raw signals from the AE sensor, the correlations of welding quality with the time and frequency domain features of the AE signals were analyzed by segmenting the signals into ten 1 ms intervals. After selection of appropriate AE signal features based on a scatter index, a hidden Markov model (HMM) classifier was employed to evaluate the performance of the selected features. Three AE signal features, namely the root mean square (RMS) of the AE signal, gradient of the first 1 ms of AE signals, and 300 kHz frequency feature, were closely related to the quality variation caused by the gap between the two layers of stainless-steel sheets. Classification accuracy of 100% was obtained using the HMM classifier with the gradient of the signal from the first 1 ms interval and with the combination of the 300 kHz frequency domain signal and the RMS of the signal from the first 1 ms interval.

scholarly journals Acoustic Emission Testing and Ib-Value Analysis of Ultraviolet Light-Irradiated Fiber Composites

2021 ◽  
Vol 11 (14) ◽  
pp. 6550
Author(s):  
Doyun Jung ◽  
Wonjin Na
Keyword(s):  
Acoustic Emission ◽  
Irradiation Time ◽  
Tensile Load ◽  
Failure Behavior ◽  
Value Analysis ◽  
Emission Testing ◽  
Final Failure ◽  
Acoustic Emission Testing ◽  
Woven Glass Fiber ◽  
Ae Signals

The failure behavior of composites under ultraviolet (UV) irradiation was investigated by acoustic emission (AE) testing and Ib-value analysis. AE signals were acquired from woven glass fiber/epoxy specimens tested under tensile load. Cracks initiated earlier in UV-irradiated specimens, with a higher crack growth rate in comparison to the pristine specimen. In the UV-degraded specimen, a serrated fracture surface appeared due to surface hardening and damaged interfaces. All specimens displayed a linearly decreasing trend in Ib-values with an increasing irradiation time, reaching the same value at final failure even when the starting values were different.

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