Detection of Fatigue Crack Growth in Aircraft Landing Gear, 4 Point Bend Test Specimens

Abstract:

This investigation considers the identification of fatigue crack growth in aerospace grade steel using Acoustic Emission (AE) techniques. Four specimens with small radius crack initiation sites were investigated under four-point bending (SENB4). A linear array of 4 resonant AE sensors was utilised to locate the crack growth. Detection and location of fatigue crack growth in aerospace grade steel SENB4 specimens using appropriate AE techniques was successful. Time of arrival (TOA) linear location has provided an invaluable tool for separating AE signals arising from fatigue crack growth from the notch from those emanating from the loading points. Analysis of the AE feature data from the notch has allowed initial categorisation of AE from fatigue crack growth. AE data from this research was found to correspond with that reported in previous studies [1] examining Compact Tension (CT) specimens.

• Periodical: Key Engineering Materials (Volumes 293-294)
• Pages: 193-200
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.293-294.193
• Online since: September 2005
• Authors: M.G. Baxter, Rhys Pullin, Karen M. Holford, S.L. Evans
• Keywords: Acoustic Emission (AE), Fatigue Testing, Landing Gear

References

[1] M.G. Baxter, R. Pullin, and K.M. Holford: Detection of fatigue crack growth in aircraft landing gear. 26th European Conference on Acoustic Emission Testing, Volume 1 (2004) pp.331-341.

[2] British Standards: Methods for Determination of the Rate of Fatigue Crack Growth in Metallic Materials, BS 6835-1: 1998 (1998).

[3] N.N. Hsu, and F.R. Brecknbridge: Characterization and Calibration of Acoustic Emission Sensors. Materials Evaluation 39 (1979) pp.60-68.

[4] RUMUL: http: /www. rumul. ch, accessed Feburary 2004 (2003).

[5] R.K. Miller, and P. McIntire: Acoustic Emission Testing. NDT Handbook Vol 5 (American Society for Non-destructive Testing 1987).