Affiliations: State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing, Jiangsu, China
Correspondence:
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Corresponding author: Zhenghua Qian, State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, Jiangsu, China. Tel.: +86 25 84892696; E-mail:qianzh@nuaa.edu.cn
Abstract: The paper proposes an inverse reconstruction method for
surface flaws in a 2-D half-space using guided Rayleigh waves. When a guided
Rayleigh wave is sent toward the flaw area, the reflected wave signals are
observed and recorded at the far field. From wave scattering theory, the
displacement field of reflected wave is expressed by an integral over the
unknown flaw surface concerning the total wave field. By introduction of
Born approximation and far-field expressions of Green's function, it is
found that the reflection coefficient in wavenumber domain is related to the
unknown shape of the cavity by a spatial Fourier transform relation. Thus,
the location and shape of unknown cavity can be established. Numerical
examples are illustrated in the paper. The research can act as a basis for
quantitative ultrasonic guided wave non-destructive inspection.
Keywords: Rayleigh wave, flaw reconstruction, scattering theory, inverse problem
