Noncontact measurement of ultrasonic attenuation during rotating fatigue test of steel

Journal Article · Tue Apr 01 04:00:00 EST 1997 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.365489· OSTI ID:496408

Ogi, H; Hirao, M; Minoura, K ^[1]

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1. Faculty of Engineering Science, Osaka University, Machikaneyama 1-3, Toyonaka, Osaka 560 (Japan)

Acoustic resonance technique has been applied to monitor the fatigue damage process of steel pipes exposed to rotating bending fatigue. The technique incorporates a superheterodyne spectrometer and an electromagnetic acoustic transducer (EMAT). The EMAT was newly developed for this purpose, and uses the magnetostrictive mechanism of ferromagnetic metals and excites and detects axial shear waves traveling around the sample pipe with axial polarization. Noncontact ultrasonic spectroscopy permits the accurate determination of the resonant frequency and the attenuation coefficient throughout the fatigue life. The attenuation coefficient shows a sharp peak around 80{percent}{endash}90{percent} of the life. The evolution is interpreted as reflecting dislocation multiplication, depinning, and formation of cell structures, which is supported by transmission electron microscopy observations. {copyright} {ital 1997 American Institute of Physics.}

• OSTI ID: 496408
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 81; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ATTENUATION
BENDING
DISLOCATION PINNING
DISLOCATIONS
FATIGUE
FERROMAGNETIC MATERIALS
MAGNETOSTRICTION
NONDESTRUCTIVE TESTING
RESONANCE
SHEAR PROPERTIES
STEELS
TRANSMISSION ELECTRON MICROSCOPY
ULTRASONIC TESTING