Generation and Detection of Higher Harmonics in Rayleigh Waves Using Laser Ultrasound
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0355 (United States)
- G.W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0405 (United States)
This research studies higher harmonics of Rayleigh surface waves propagating in nickel base superalloys. Rayleigh waves are used because they carry most of the energy and travel along the surface of a specimen where fatigue damage is typically initiated. The energy concentration near the free surface leads to stronger nonlinear effects compared to bulk waves. An ultrasonic piezoelectric transducer together with a plastic wedge is used for the experimental generation of the Rayleigh wave. The detection system consists of a laser heterodyne interferometer. Measurements are performed to detect the fundamental wave as well as the second harmonic. The amplitude ratio is related to the nonlinearity parameter {beta} which is typically used to describe changes in microstructure and investigate fatigue damage.
- OSTI ID:
- 20798251
- Journal Information:
- AIP Conference Proceedings, Vol. 820, Issue 1; Conference: Conference on review of progress in quantitative nondestructive evaluation, Brunswick, ME (United States), 31 Jul - 5 Aug 2005; Other Information: DOI: 10.1063/1.2184538; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
- Country of Publication:
- United States
- Language:
- English
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