scholarly journals Proportional monitoring of the acoustic emission in crypto-conditions

2011 ◽  
Vol 59 (5) ◽  
pp. 31-38 ◽  
Author(s):  
Petr Dostál ◽  
Michal Černý ◽  
Jaroslav Lev ◽  
David Varner
Keyword(s):  
Acoustic Emission ◽  
Aluminum Alloys ◽  
Real Time ◽  
Fatigue Cracks ◽  
Current Status ◽  
Fatigue Properties ◽  
Material Degradation ◽  
Emission Method ◽  
Important Benefit ◽  
Ae Signals

The work is aimed at studying corrosion and fatigue properties of aluminum alloys by means of acoustic emission (AE). During material degradation are acoustic events scanned and evaluated. The main objective of the article is a description of behavior of aluminum alloys degraded in specific conditions and critical degradation stages determination. The first part of the article describes controlled degradation of the material in the crypto–conditions. The acoustic emission method is used for process analyzing. This part contains the AE signals assessment and comparing aluminium alloy to steel. Then the specimens are loaded on high-cyclic loading apparatus for fatigue life monitoring. Also, the synergy of fatigue and corrosion processes is taken into account.The aim is the description of fatigue properties for aluminum alloys that have already been corrosion-degraded. Attention is also focused on the structure of fatigue cracks. The main part of the article is aimed at corrosion degradation of aluminium alloys researched in real time by means of AE. The most important benefit of AE detection/recording is that it provides information about the process in real time. Using this measurement system is possible to observe the current status of the machines/devices and to prevent serious accidents.

scholarly journals Separation of AE signals for detecting solidification cracking of Al–7 mass%Si alloy by using acoustic emission method

2010 ◽  
Vol 60 (10) ◽  
pp. 492-498 ◽  
Author(s):  
Itaru Endo ◽  
Hiroyuki Chiba ◽  
Toru Ueki ◽  
Takanari Toriyama ◽  
Makoto Yoshida
Keyword(s):  
Acoustic Emission ◽  
Solidification Cracking ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Ae Signals

scholarly journals Comparative analysis of the strength of restoration polymers of light polymerization for dental restoration using the acoustic emission method: part one

2021 ◽  
Vol 107 (3) ◽  
pp. 26-32
Author(s):  
V. Kukhta ◽  
◽  
V. Makeev ◽  
O. Kyrmanov ◽  
V. Skalsky ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Comparative Analysis ◽  
High Energy ◽  
Dental Restoration ◽  
Acoustic Emission Method ◽  
Local Loading ◽  
Emission Method ◽  
Composite Failure ◽  
Initial Stage ◽  
Ae Signals

Purpose. Comparative analysis of the strength of hybrid restoration composites of light polymerization during their local loading using the phenomenon of acoustic emission. The following restoration composites were studied: Latelux, Tetric N-Ceram, Charisma Classic. Results. It was determined that the nature of the destruction of all composites is the same: elastic-plastic at the initial stage of the load with a transition to brittle as its further growth. Three types of composite failure are observed: correct, incorrect and mixed. The first predominated during fracture under the action of local loading of the Latelux composite, for Tetric N-Ceram and Charisma Classic materials a mixed type of fracture is characteristic. Conclusions. Analysis of the parameters of the AE signals showed that the signals had the highest amplitude and energy when the Tetric N-Ceram composite was destroyed, and the lowest – Latelux. All dental composites are dominated by high-energy ductile-brittle and brittle fracture, which indicates the spread of micro- and macrocracks of various sizes in materials. Key words: polymer composites, strength, acoustic emission method.

Fatigue Modeling of Friction-Stir-Welded (FSW) Butt-Joints for Aerospace Applications

2019 ◽  
Author(s):  
Muhammad A. Wahab ◽  
Vinay Raghuram
Keyword(s):  
Fatigue Life ◽  
Aluminum Alloys ◽  
Fracture Mechanics ◽  
Crack Propagation ◽  
Fatigue Cracks ◽  
Strength Criterion ◽  
Fatigue Properties ◽  
Interface Element ◽  
Friction Stir ◽  
Stress Ratios

Abstract Among the recent research Friction-Stir-Welding (FSW) has been adopted worldwide as one of the dominant processes for welding lightweight aerospace Aluminum alloys. Al-2195 which is one of the new generation Aluminum alloys has been used in the external tank of the space shuttles. Aerospace fabricators are continuously pursuing FSW-technologies in its efforts to advance fabrication of the external tanks of the space shuttles. The future launch vehicles with reusable mandates require the structures to have excellent fatigue properties and improved fatigue lives. The butt-welded specimens of Al-2195 and Al-2219 are fatigue tested according to ASTM-E647. The effects of stress ratios, use of corrosion preventive compound (CPC), and the applications of periodic overloading on fatigue lives are investigated in this study. Scanning-electron-microscopy (SEM) is used to examine the criticality of the failure surfaces and the different modes of crack propagation that could have been initiated into the materials. It is found that fatigue life increases with the increase in stress ratio, and results show an increase in fatigue life ranging over 30% with the use of CPC, and the fatigue life increases even further with periodic overloading; whereas crack-closure phenomenon predominates the fatigue fracture. Fracture mechanics analysis and crack similitude was modified for fatigue cracks by Paris. Numerical studies using FEA has produced a model for fatigue life prediction scheme for these structures, where a novel strategy of the interface element technique with critical bonding strength criterion for formation of new fracture surfaces has been used to model fatigue crack propagation lives. The linear elastic fracture mechanics stress intensity factor is calculated using FEA and the fatigue life predictions made using this method are within 10–20% of the experimental fatigue life data obtained. This method overcomes the limitation of the traditional node-release scheme and closely matches the physics of the crack propagation.

Monitoring of the High-Technology Nailing of CFRTP Material under Ultrasonic Vibration by Acoustic Emission Method

2020 ◽  
Vol 1009 ◽  
pp. 25-30
Author(s):  
Yoshiaki Akematsu ◽  
Hiromitsu Gotho ◽  
Takayuki Tani ◽  
Hideaki Murayama ◽  
Tsuyoshi Matsuo ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Ultrasonic Vibration ◽  
Energy Parameter ◽  
High Technology ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Thermoplastic Material ◽  
Signal Characteristics ◽  
Ae Signal ◽  
Ae Signals

In this study, the potential to monitor the high-technology nailing of carbon fiber reinforced thermoplastic material (CFRTP) under ultrasonic vibration was investigated by acoustic emission (AE) method. AE signals were detected by a piezoelectric AE sensor during high-technology nailing under ultrasonic vibration. This paper describes some experimental results on AE signal characteristics and observation of the high-technology nailing. In order to investigate the effects of machining condition, we focused on RMS voltage, which is dependent on the energy parameter of the AE signal. It was found that the AE method is a useful method of monitoring high-technology nailing.

Empirical Approach to Defect Detection Probability by Acoustic Emission Testing

2021 ◽  
Vol 11 (20) ◽  
pp. 9429
Author(s):  
Vera Barat ◽  
Artem Marchenkov ◽  
Valery Ivanov ◽  
Vladimir Bardakov ◽  
Sergey Elizarov ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Defect Detection ◽  
Probabilistic Models ◽  
Fatigue Cracks ◽  
A Priori ◽  
Empirical Approach ◽  
Empirical Generalization ◽  
Microstructure Parameters ◽  
A Priori Estimation ◽  
Ae Signals

Estimation of probability of defect detection (POD) is one of the most important problems in acoustic emission (AE) testing. It is caused by the influence of the material microstructure parameters on the diagnostic data, variability of noises, the ambiguous assessment of the materials emissivity, and other factors, which hamper modeling the AE data, as well as the a priori determination of the diagnostic parameters necessary for calculating POD. In this study, we propose an empirical approach based on the generalization of the experimental AE data acquired under mechanical testing of samples to a priori estimation of the AE signals emitted by the defect. We have studied the samples of common industrial steels 09G2S (similar to steel ANSI A 516-55) and 45 (similar to steel 1045) with fatigue cracks grown in laboratory conditions during cyclic testing. Empirical generalization of data using probabilistic models enables estimating the conditional probability of record emissivity and amplitudes of AE signals. This approach allows to eliminate the existing methodological gap and to build a comprehensive method for assessing the probability of fatigue cracks detection by the AE testing.

Acoustic Emission Method for Real-Time Detection of Steel Fatigue Crack in Eyebar

2012 ◽  
Vol 2313 (1) ◽  
pp. 72-79 ◽  
Author(s):  
Michael B. Johnson ◽  
Didem Ozevin ◽  
Glenn A. Washer ◽  
Kanji Ono ◽  
Richard S. Gostautas ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Real Time ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Real Time Detection

Detection and Monitoring of Fatigue Cracks in Metallic Structures Using Acoustic Emission: Routes to Quantification of Probability of Detection

2014 ◽  
Vol 891-892 ◽  
pp. 1268-1274 ◽  
Author(s):  
Daniel Gagar ◽  
Peter Foote ◽  
Phil E. Irving
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Cracks ◽  
Failure Process ◽  
Probability Of Detection ◽  
Metallic Structures ◽  
Final Failure ◽  
Ae Signal ◽  
Non Destructive ◽  
Ae Signals

The performance and reliability of Structural Health Monitoring (SHM) techniques remain largely unquantified. This is in contrast to the probability of detection (POD) and sensitivity of manual non destructive inspection methods which are well characterised. In this study factors influencing the rates of emission of Acoustic Emission (AE) signals from propagating fatigue cracks were investigated. Fatigue crack growth experiments were performed in 2014 T6 aluminium sheet to observe the effects of changes in crack length, loading spectrum and sample geometry on rates of emission and the probability of detecting and locating the fatigue crack. Significant variation was found in the rates of AE signal generation during crack progression from initiation to final failure. AE signals at any point in the failure process were found to result from different failure mechanisms operating at particular stages in the failure process.

scholarly journals Assessment of the technical condition of prefabricated elements using the acoustic emission method

2019 ◽  
Vol 28 (3) ◽  
pp. 356-365 ◽  
Author(s):  
Aleksandra Krampikowska ◽  
Anna Adamczak-Bugno
Keyword(s):  
Acoustic Emission ◽  
Prestressed Concrete ◽  
Technical Condition ◽  
Acoustic Emission Method ◽  
Material Degradation ◽  
Emission Method ◽  
Destructive Processes ◽  
Two Stages ◽  
The Impact ◽  
Concrete Elements

The article presents the results of tests using the acoustic emission method during the formation process of T-27 prestressed concrete beams. The studies included two stages. The first – testing the compressive strength of the cubic samples taken from the trial batch used for the production of beams together with the acquisition of acoustic emission signals. The second – measurements by acoustic emission, on the actual construction element during accelerated maturation of concrete caused by heating. The undertaking of the above subject results from the fact that this issue is of great importance when assessing the durability of reinforced concrete and pre-compressed elements in the aspect of the analysis of these structures in terms of durability. The impact of material degradation on the durability of the structure is difficult to appraise due to the lack of reliable results needed to estimate the durability of the selected statistical approach. However, the use of the acoustic emission method based on the identification of destructive processes creates the possibility of locating, identifying and monitoring the emerging and developing destructive processes affecting the durability of concrete elements.

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