#### Location

La Jolla, CA

#### Start Date

1979 12:00 AM

#### Description

Various analytical methods based on the real reciprocity relation are applied to the problem of Rayleigh wave scattering by a surface crack. In one formulation, the reflection coefficient observed at the transducer terminals is expressed in terms of an integral over the crack surface of the product of the perturbed and unperturbed fields. This integral is then converted to a volume integral and the Born Approximation is applied. In the other formulation a "Kirchoff" type approach is used such that the effect of the crack is expressed as an equivalent body force distribution. That force distribution is then approximated and normal mode techniques are used to find the scattered field amplitude. The two methods are compared with each other and with the results obtained from geometrical diffraction theory. An experimental procedure is also proposed for the inverse problem.

#### Book Title

Proceedings of the ARPA/AFML Review of Progress in Quantitative NDE

#### Chapter

14. Surface Measurements

#### Pages

498-504

#### Language

en

#### File Format

application/pdf

Characterization of Surface Wave Scattering by Surface Breaking Cracks

La Jolla, CA

Various analytical methods based on the real reciprocity relation are applied to the problem of Rayleigh wave scattering by a surface crack. In one formulation, the reflection coefficient observed at the transducer terminals is expressed in terms of an integral over the crack surface of the product of the perturbed and unperturbed fields. This integral is then converted to a volume integral and the Born Approximation is applied. In the other formulation a "Kirchoff" type approach is used such that the effect of the crack is expressed as an equivalent body force distribution. That force distribution is then approximated and normal mode techniques are used to find the scattered field amplitude. The two methods are compared with each other and with the results obtained from geometrical diffraction theory. An experimental procedure is also proposed for the inverse problem.