Nonlinear Elasticity and Nondestructive Evaluation and Imaging

Abstract

Based on methods described in the previous chapters, we now turn to applications to nondestructive evaluation. In Section 13.1 we provide a general overview and perspective. Following this, Section 13.2 provides a historical overview of the development of the domain in metals, long before rocks and other materials were discovered to exhibit the same behaviors. In Section 13.3 a simple crack model based on work by a number of individuals, but primarily Igor Solodov, is described. Following this, we describe methods that are part of what we call nonlinear elastic wave spectroscopy (NEWS), Section 13.4. Contained in this group are modulation methods (Section 13.4.1), resonance methods (Section 13.4.5), signal ringdown methods (Section 13.4.6), and methods based on slow dynamics (Section 13.4.7). We then describe a number of measurements of progressive damage employing a number of NEWS methods in Section 13.5. Methods of localization and imaging follow in Section 13.6 based on harmonics (Section 13.6.1) and wave modulation (Section 13.6.2) and time reversal (Section 13.6.3). Before summarizing, two other methods of isolating the nonlinear response are described as well (Sections 13.7.1 and 13.7.2, respectively). OverviewOver the past decade or so in particular there have been many developments in the area of nondestructive evaluation. The area is relatively well developed; however, the quantitative relationship between elastic nonlinear response and mechanical (or other) damage is still an open area that requires significant attention. That said, discerning that damage is present and localizing it are well advanced. In what follows, we first provide a historical overview of nondestructive evaluation based on nonlinear elastic means. We then describe the relatively large number of diagnostic and imaging methods by example, linking the method to rigorous development in previous chapters. Following this we describe imaging methods.