Generation, Annihilation and Flow of Structural Information in Ultrasonic Nondestructive Evaluation

TL;DR

This paper formalizes and quantifies the concept of information in ultrasonic nondestructive testing, deriving a balance equation and exploring how structural information is generated, flows, and is annihilated within tested objects.

Contribution

It introduces a novel physical framework for understanding and quantifying information in ultrasonic testing, linking it to practical applications and existing information theories.

Findings

Derived a balance equation for ultrasonic information analogous to Poynting's theorem.

Demonstrated pathways of information flow from defects to sensors.

Discussed implications for structural health monitoring and machine learning.

Abstract

Non-destructive testing using ultrasound is based on the interaction of sound waves with the object being tested and any defects it may contain. The aim is to extract as much information as possible about the object and its defects from the scattered wave field. In this paper, the concept of information in the context of ultrasonic testing is formalized and quantified physically for the first time. To this end, a balance equation for information is derived, analogous to Poynting's theorem for elastic energy. Various examples demonstrate how structural information is generated and annihilated within a component and along which pathways it travels from the defect to the sensor. Subsequently, the significance and potential of this new information concept for practical ultrasonic testing, structural health monitoring, numerical simulation, and machine learning are discussed. Finally, similarities and differences to mathematical Shannon information and statistical Fisher information are highlighted.