Theoretical Predictions and Experimental Measurements of Echo Responses from Tilted Flat-Bottomed Holes

Abstract

<p>In some earlier work, semi-analytic methods were proposed to predict echo responses from point-like targets [1] and normally aligned flat-bottomed holes in solids (FBH) [2]. A new, more general formulation has recently been developed (hereafter, the “elastic model” [3]), capable of predicting responses from defects of arbitrary shape. In this paper, theoretical predictions using the new model are compared with experimentally measured echo responses from tilted FBH’s, where the hole bottom is tilted relative to the transducer axis. A related study [4] has already been presented in which experimental echo responses from tilted disks immersed in a fluid were compared with results predicted by an earlier model [5]. In that earlier model, mode conversion was not taken into account and only compression waves were considered (the “acoustic model”).</p>