  | AET - Full Paper Not Received |  |
SPECTRAL ANALYSIS OF ACOUSTIC EMISSION SIGNALS PICKED UP DURING DIFFERENT PHASES OF CRACK GROWTH
Sudha Raman, Muthukrishnan and C. R. L. Murthy
Aerospace Engineering Department, Structures Division
Indian Institute of Science, Bangalore 560 012, India
Keywords: NDT, Spectral Analysis Acoustic Emission, Crack growth, Background noise, Transient signal
ABSTRACT Several attempts have been made in the past to detect incipient cracks in aircraft's structural parts during the flight itself. Acoustic emission (AE) has been found to be very suitable method. The technique however suffers from the drawback viz. that it cannot distinguish between a crack induced signal and those from background noise as the transient signal pattern look alike for both. Effort was therefore made by us to conduct experiments to simulate various background noises including crack. The present work deals with the analysis of results from a typical crack signal. The analysis is in spectral domain and covers various stages of crack growth during the fatigue cycle. Tests were conducted on a Duralumin specimen with a cyclic load varying from 250/25 kg to 50 kg. AE signals were collected and digitised. Frequency components belonging to various typical events were isolated.
| | AET - Full Paper Not Received | |
Publication Source: Trends in NDE Science & Technology; Proceedings of the 14th World Conference on Non-Destructive Testing, New Delhi, 8-13 December 1996.full paper not received
Publisher: Ashgate Publishing Company
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