Identifying transition of fatigue cracks from tensile to shear mode based on acoustic emission signals

2019 ◽  
Author(s):  
Kassahun Asamene ◽  
Duy Q. Tran ◽  
Mannur J. Sundaresan
Keyword(s):  
Acoustic Emission ◽  
Fatigue Cracks ◽  
Shear Mode

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.

scholarly journals Acoustic emission for monitoring aircraft structures

2009 ◽  
Vol 223 (5) ◽  
pp. 525-532 ◽  
Author(s):  
K M Holford ◽  
R Pullin ◽  
S L Evans ◽  
M J Eaton ◽  
J Hensman ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Magnetic Particle ◽  
Fatigue Cracks ◽  
Principal Component ◽  
Fatigue Loading ◽  
Probability Density Functions ◽  
Aircraft Industry ◽  
Safety And Reliability ◽  
Critical Components

Structural health monitoring (SHM) is of paramount importance in the aircraft industry: not only to ensure the safety and reliability of aircraft in flight and to ensure timely maintenance of critical components, but also increasingly to monitor structures under test for airworthiness certification of new designs. This article highlights some of the recent advances in the acoustic emission (AE) technique as applied to SHM, and the new approaches that are crucial for the successful use of AE data for diagnostic purposes. These include modal analysis, enhanced location techniques, and novel signal processing approaches. A case study is presented on a landing gear component undergoing fatigue loading in which a linear location analysis using conventional techniques identified the position of fracture and final rupture of the specimen. A principal component analysis approach was used to separate noise signals from signals arising from fatigue cracks, which identified and located further fatigue crack positions, subsequently confirmed by magnetic particle inspection. Kernel probability density functions are used to aid visualization of the damage location.

Acoustic-emission inspection of the kinetics of fatigue cracks in turbomachinery disks

1992 ◽  
Vol 25 (6) ◽  
pp. 303
Author(s):  
M.D. Banov ◽  
A.A. Shanyavaskii ◽  
A.I. Urbakh ◽  
D.A. Troenkin ◽  
E.A. Konyaev ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Fatigue Cracks ◽  
Kinetics Of

Special features of acoustic emission from fatigue cracks in welded joints in oil pipes

1992 ◽  
Vol 25 (6) ◽  
pp. 295
Author(s):  
A.G. Golovinskii ◽  
A.V. Kiselev ◽  
A.M. Kotkis ◽  
N.F. Khokhlov ◽  
A.M. Shiryaev
Keyword(s):  
Acoustic Emission ◽  
Welded Joints ◽  
Fatigue Cracks
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