Guided Wave Acoustic Emission from Fatigue Crack Growth in Aluminium Plate

2006 ◽  
Vol 13-14 ◽  
pp. 23-28 ◽  
Author(s):  
C.K. Lee ◽  
Jonathan J. Scholey ◽  
Paul D. Wilcox ◽  
M.R. Wisnom ◽  
Michael I. Friswell ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Elastic Waves ◽  
Fatigue Cracks ◽  
Guided Wave ◽  
Experimental Results ◽  
Multiple Reflections ◽  
Alloy Plate

Acoustic emission (AE) testing is an increasingly popular technique used for nondestructive evaluation (NDE). It has been used to detect and locate defects such as fatigue cracks in real structures. The monitoring of fatigue cracks in plate-like structures is critical for aerospace industries. Much research has been conducted to characterize and provide quantitative understanding of the source of emission on small specimens. It is difficult to extend these results to real structures as most of the experiments are restricted by the geometric effects from the specimens. The aim of this work is to provide a characterization of elastic waves emanating from fatigue cracks in plate-like structures. Fatigue crack growth is initiated in large 6082 T6 aluminium alloy plate specimens subjected to fatigue loading in the laboratory. A large specimen is utilized to eliminate multiple reflections from edges. The signals were recorded using both resonant and nonresonant transducers attached to the surface of the alloy specimens. The distances between the damage feature and sensors are located far enough apart in order to obtain good separation of guided-wave modes. Large numbers of AE signals are detected with active fatigue crack propagation during the experiment. Analysis of experimental results from multiple crack growth events are used to characterize the elastic waves. Experimental results are compared with finite element predictions to examine the mechanism of AE generation at the crack tip.

Guided Wave Acoustic Emission from Fatigue Crack Growth in Aluminium Plate

2006 ◽  
pp. 23-28 ◽  
Author(s):  
C.K. Lee ◽  
Jonathan J. Scholey ◽  
Paul D. Wilcox ◽  
M.R. Wisnom ◽  
M. I. Friswell ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Guided Wave

Acoustic emission and guided wave monitoring of fatigue crack growth on a full pipe specimen

2011 ◽  
Author(s):  
R. M. Meyer ◽  
S. Cumblidge ◽  
P. Ramuhalli ◽  
B. Watson ◽  
S. R. Doctor ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Guided Wave

scholarly journals Determining the Characteristics of Acoustic Emission in the Fatigue Crack Growth of Aluminum Alloy 2025 for Online Structural Monitoring

2021 ◽  
Author(s):  
Javad Sharifi Ghaderi
Keyword(s):  
Acoustic Emission ◽  
Aluminum Alloy ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Cracks ◽  
Structural Monitoring ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Non Destructive

In the use of metals, due to industrial advances and the application of more dynamic loads, it is necessary to pay more attention to the fatigue issue. Non-destructive inspection methods are used to condition and health monitoring of structures at the time of production and even during the service life of parts. Among non-destructive methods, the acoustic emission method has become a standard and reliable method in recent years. In this project, the characteristics of acoustic emission in the fatigue crack growth of aluminum alloy 2025 for online structural monitoring have been investigated and determined. Acoustic emission tests have been performed in two parts: bending fatigue test with the aim of initiation of fatigue cracks in aluminum alloy 2025 specimens and following tensile tests with the aim of growth of fatigue cracks. The acoustic emission signals and parameters sent by the acoustic emission sensor during both tests were received and recorded by the acoustic emission software. According to the received acoustic emission information, various diagrams are plotted. Analyzing the results from online acoustic emission monitoring showed, the acoustic emission method can be considered as a suitable and reliable technique for detecting crack initiation and crack growth in aluminum alloy 2025.

scholarly journals Acoustic Emission Monitoring of Fatigue Crack Growth in Mooring Chains

2019 ◽  
Vol 9 (11) ◽  
pp. 2187 ◽  
Author(s):  
Ángela Angulo ◽  
Jialin Tang ◽  
Ali Khadimallah ◽  
Slim Soua ◽  
Cristinel Mares ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Large Scale ◽  
Fatigue Cracks ◽  
Fatigue Crack Initiation ◽  
Fatigue Loading ◽  
Damage Initiation ◽  
High Level

Offshore installations are subject to perpetual fatigue loading and are usually very hard to inspect. Close visual inspection from the turret is usually too hazardous for divers and is not possible with remotely operated vehicles (ROVs) because of the limited access. Conventional nondestructive techniques (NDTs) have been used in the past to carry out inspections of mooring chains, floating production storage and offloading systems (FPSOs), and other platforms. Although these have been successful at detecting and assessing fatigue cracks, the hazardous nature of the operations calls for remote techniques that could be applied continuously to identify damage initiation and progress. The aim of the present work is to study the capabilities of acoustic emission (AE) as a monitoring tool to detect fatigue crack initiation and propagation in mooring chains. A 72-day large-scale experiment was designed for this purpose. A detailed analysis of the different AE signal time domain features was not conclusive, possibly due to the high level of noise. However, the frequency content of the AE signals offers a promising indication of fatigue crack growth.

Study of fatigue crack growth in RAFM steel using acoustic emission technique

2016 ◽  
Vol 126 ◽  
pp. 107-116 ◽  
Author(s):  
M. Nani Babu ◽  
C.K. Mukhopadhyay ◽  
G. Sasikala ◽  
Shaju K. Albert ◽  
A.K. Bhaduri ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Acoustic Emission Technique ◽  
Rafm Steel

Estimation of the Shape Evolution and the Growth History of an Embedded Crack by Fatigue Loading

2011 ◽  
Author(s):  
Koji Gotoh ◽  
Keisuke Harada ◽  
Yosuke Anai
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Cracks ◽  
Estimation Method ◽  
Estimation Procedure ◽  
Fatigue Loading ◽  
Shape Evolution ◽  
Crack Growth Behaviour ◽  
Embedded Crack

Fatigue life estimation for planar cracks, e.g. part-through surface cracks or embedded cracks is very important because most of fatigue cracks found in welded built-up structures show planar crack morphologies. Fatigue crack growth behaviour of an embedded crack in welded joints is investigated in this study. The estimation procedure of crack shape evolution for an embedded crack is introduced and validation of the estimation procedure of fatigue crack growth based on the numerical simulation of fatigue crack growth with EDS concept for an embedded crack is performed. The validity of the proposed shape evolution estimation method and the fatigue crack growth simulation based on the fracture mechanics approach with EDS concept are confirmed.

A Method for the Analysis of the Growth of Short Fatigue Cracks

1995 ◽  
Vol 117 (4) ◽  
pp. 408-411 ◽  
Author(s):  
A. J. McEvily ◽  
Y.-S. Shin
Keyword(s):  
Experimental Data ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Cracks ◽  
Material Constant ◽  
Plastic Zone Size ◽  
Surface Cracks ◽  
Zone Size ◽  
Short Cracks

A method for the analysis of the fatigue crack growth rate for short cracks has been developed and is applied to the case of fatigue crack growth of short surface cracks in a 1045 carbon steel. The method entails three modifications to standard LEFM procedures. These modifications include the use of a material constant to bridge between smooth and cracked specimen behavior, consideration of the plastic zone size to crack length ratio, and incorporation of the development of crack closure. Comparisons are made between calculations based upon this approach and experimental data.

Evaluation of Fatigue Crack Growth Characteristics on Stainless Steel SS 316 LN Using Acoustic Emission Technique

2020 ◽  
Author(s):  
Raghu V. Prakash ◽  
Manuel Thomas
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Fatigue Crack ◽  
Elevated Temperature ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Acoustic Waves ◽  
Crack Advance ◽  
Cumulative Energy ◽  
Good Correspondence

Abstract Results of online acoustic emission (AE) monitoring during fatigue crack growth rate (FCGR) experiments on a stainless steel SS 316 LN are presented in this paper. Two specimen geometries — viz., standard compact tension (C(T)) specimens as well as side-grooved C(T) specimens were considered for experiments at ambient temperature and at 600°C (873K). There is a good correspondence between crack length increment and the increase in AE cumulative count and cumulative energy during the experiments. The side grove introduced on the thickness direction of the test specimen constrains the plastic zone ahead of the crack tip, thereby enforcing plane strain conditions at the crack. Reduced AE activity at initial stages of crack growth was observed for side grooved samples. The transition to Stage-II crack growth was observed using acoustic emission (AE) technique which otherwise was not visible from the fatigue crack growth plot. The work further attempts to correlate the AE parameters obtained during elevated temperature (873K) fatigue crack growth in stainless steel. For the purpose of acquiring AE signals outside the heated zone, a waveguide was used to transmit the acoustic waves from the specimen at high temperature. A correlation between crack advance and AE parameters was obtained from the elevated temperature tests.

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