Ultrasonic Caustics and the Inverse Scattering Problem in NDE

dc.contributor.author Doyle, P
dc.date 2018-02-16T16:39:38.000
dc.date.accessioned 2020-06-30T06:27:49Z
dc.date.available 2020-06-30T06:27:49Z
dc.date.issued 1980
dc.description.abstract <p>This paper explores theoretically the possibility of using caustics, formed in the ultrasonic field diffracted by defects, as an approach to the inverse scattering problem, The case of crack-like defects is considered in detail, using the geometrical theory of diffraction. The involute of the far field caustic reproduces the projection of the crack edge in the incident beam direction, for a plane incident wavefront. This purely geometrical inversion is carried out uniquely for the astroid and its involute, the elliptical edge. For a general edge shape, the complete inversion requires one further length measurement, which may be carried out in some cases by further experiments with caustics, Usefullimitations on the possible shapes of caustics are explained on the basis of catastrophe theory, Calculations show that the inherent intensity-level change (~2-3 dB) and width ( <strong>~</strong> wavelength) over which it occurs for a typical ultrasonic caustic are adequate for observation. Some discussion is given of experimental requirements, as well as of caustics formed in the near field of a crack and of those formed by voids and inclusions. The topology of the far field caustic cannot in general distinguish between volumetric and crack-like defects. Studying caustics may prove to be a useful adjunct to ultrasonic imaging systems for the inspection of fatigue cracks.</p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/qnde/1979/allpapers/32/
dc.identifier.articleid 4674
dc.identifier.contextkey 7290187
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath qnde/1979/allpapers/32
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/58350
dc.language.iso en
dc.relation.ispartofseries Review of Progress in Quantitative Nondestructive Evaluation
dc.source.bitstream archive/lib.dr.iastate.edu/qnde/1979/allpapers/32/1979_YellowJacket_073_Doyle_UltrasonicCaustics.pdf|||Fri Jan 14 23:33:51 UTC 2022
dc.subject.disciplines Acoustics, Dynamics, and Controls
dc.subject.disciplines Engineering Mechanics
dc.subject.disciplines Mechanics of Materials
dc.title Ultrasonic Caustics and the Inverse Scattering Problem in NDE
dc.type event
dc.type.genre event
dspace.entity.type Publication
relation.isSeriesOfPublication 289a28b5-887e-4ddb-8c51-a88d07ebc3f3
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