Search

The TOFD (Time of Flight Diffraction) Technique is commonly used to detect and to characterize embedded disoriented flaws using their edge diffraction echoes. We present a TOFD simulation module which includes GTD coefficients allowing to predict diffraction echoes from embedded planar flaws. Other dedicated development have been added in the CIVA software platform to simulate lateral surface waves, backwall echoes and shadowing effects from flaws. Experimental validations have been performed on various specimen containing rectangular and CAD contour planar flaws with different possible disorientations (tilt, vertical misorientation, skew) and show an overall good agreement between simulation and measure. [ABSTRACT FROM AUTHOR]

Interfacial cracks are ubiquitous in industrial components and modelling their interaction with ultrasonic fields is an outstanding problem. In this paper we address one of the relevant canonical mathematical problems — diffraction of a plane wave by a two-dimensional semi-infinite crack sandwiched in-between two different isotropic half-planes. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

It is of importance in ultrasonic NDE to know how crack roughness effects the quality of inspection. Rough crack face was modeled in the past as a mosaic of large triangles using the Kirchhoff approximation. On the other hand, until now rough crack edge was modeled only under assumption of small perturbation. In this paper, in the spirit of the triangular facet model we model rough crack edge as a polygonal line and then apply the Isakovich approach which was developed for scatter from rough surfaces and is also based on the Kirchhoff approximation. For simplicity, we deal with a planar crack. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]