NDE MODELS — AN ENGINEERING BASE FOR CHARACTERIZING DISCRETE ANOMALIES AND CONTINUOUSLY DISTRIBUTED MATERIAL PROPERTIES

Abstract Over the past several years, analytic and numerical models have been developed that describe various details of the measurement process for several NDE modalities (ultrasonics, eddy current, and radiography). These "measurement models". Probability of Detection (POD) models, and more recently. their coupling to Computer-Aided-Design (CAD) now provide an engneering base for the characterization of discrete anomalies. Examples of these advances will be reviewed, including their enabling role in the achievement of an inspectability in-design capability. Discussion will then turn to similar advances for the case of variations in continuously distributed material propertics rather than discrete flaws. Some examples of this case exist. such as the characterization of porosity and grain structure, and will be reviewed. It will be suggested that an extension of these modelling capabilities is an important element of the nondestructive characterization of materials and of such engineering paradigms as Int...