Inspection of fatigue crack growth in a cast steel by the acoustic emission method

1987 ◽  
Vol 19 (1) ◽  
pp. 45-49
Author(s):  
E. Yu. Nefed'ev ◽  
V. A. Volkov ◽  
A. I. Lyashkov ◽  
V. N. Savel'ev
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Cast Steel ◽  
Acoustic Emission Method ◽  
Emission Method

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.

Acoustic Emission as a Tool of Fatigue Assessment

2006 ◽  
Vol 306-308 ◽  
pp. 271-278 ◽  
Author(s):  
Kyung Seop Han ◽  
Kwang Hwan Oh
Keyword(s):  
Acoustic Emission ◽  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Fatigue Damage ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Fatigue Assessment ◽  
Emission Parameter ◽  
Acoustic Emission Parameter ◽  
Creep Fatigue

A series of laboratory investigations concerned about fatigue assessment with acoustic emission method was presented. Fatigue aspects including cumulative fatigue damage, fatigue crack growth and creep-fatigue interaction were considered. As a basic approach, residual strength and acoustic emission characteristics of fatigue damaged materials were considered from the nominal stress-life (S-N) viewpoint. Acquired signal indicated that counts emission quantity can be a good measure of cumulated fatigue damage. In the fatigue crack growth approach, interrelationship between acoustic emission parameter and stress intensity factor was examined with different stress level and crack length. Experimental results were somewhat scattered since sensitive characteristics of acoustic emission method. However, their empirical relation indicated that counts rate correlated with fracture mechanics parameter. Finally, acoustic emission application was extended to the creep-fatigue interaction at elevated temperature. Emission response under each damage mode was compared and characterized. Based on these characteristics, creep-fatigue interaction was evaluated by use of acoustic emission parameter. Overall investigations concluded acoustic emission is very effective tool of fatigue assessment.

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.

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

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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