Detection of Fatigue Crack Growth in Aircraft Landing Gear, 4 Point Bend Test Specimens
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  examining Compact Tension (CT) specimens.
W.M. Ostachowicz, J.M. Dulieu-Barton, K.M. Holford, M. Krawczuk and A. Zak
M.G. Baxter et al., "Detection of Fatigue Crack Growth in Aircraft Landing Gear, 4 Point Bend Test Specimens ", Key Engineering Materials, Vols. 293-294, pp. 193-200, 2005