Model-Based Ultrasonic Flaw Classification and Sizing

The problem of flaw characterization can be viewed as a multi-step process (Fig. 1) where decisions are made as to flaw type (a classification process) and geometry (a sizing process). Previously, we have described our work on the use of the expert system FLEX for determining if an unknown flaw is a volumetric flaw or a crack [1] and the use of equivalent flaw sizing algorithms whereby the flaw is sized in terms of a best fit ellipsoid (for volumetric flaws) or ellipse (for cracks) [2]. Here, we will describe some of our work on how classification information can be used to improve sizing estimates and on the use of new, more efficient sizing algorithms