Mechanical Reciprocity Principles and Ultrasonic Measurement Models

Abstract

An electromechanical reciprocity relation derived by Auld [1] has become a powerful tool for modeling many ultrasonic NDE experiments. Auld’s relation has also served as the foundation for developing more explicit models of ultrasonic systems, such as the quasi-plane wave measurement model of Thompson and Gray [2], which has been used for a variety of quantitative calibration, classification, and flaw sizing applications. Here, we will develop a relationship similar to that of Auld’s but using simpler mechanical reciprocity relations. One side benefit of this mechanical reciprocity approach will be an explicit statement of the manner in which ultrasonic transducers are mechanically reciprocal to one another.