Rayleigh wave scattering from surface features: up-steps and troughs

Abstract The development of a method of sizing surface defects based on Rayleigh waves has been hampered by the lack of a theory to describe the scattering problem. In an earlier paper 1 we described a new mixed finite element/finite difference model, which provides accurate and stable numerical solutions for faceted scattering geometries. This paper presents details of the interaction of Rayleigh waves with angled up-steps which, combined with our earlier discussion of angled down-steps, provides new insights into the scattering of pulsed surface waves from faceted troughs. Numerical visualizations, seismograms and spectral Rayleigh wave scattering coefficients provide a detailed description of the scattering process. The implications of the results for a non-destructive testing method for surface feature characterization are discussed.

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