Guided Wave Studies for Enhanced Acoustic Emission Inspection

Fundamental elements of wave mechanics are covered with respect to Acoustic Emission (AE) analysis in Nondestructive Evaluation (NDE) and Structural Health monitoring (SHM). Emphasis is placed on aspects of Ultrasonic Guided Waves that travel in a structure due to elastic wave emissions from a defect source as defects continue to grow. The AE Method is based on the emission of elastic waves from a particular source as failure is initiated - crack, corrosion, leak, and so on. The AE signal received is a function of the source orientation and location as well as wave velocities in the structure, sensor types and positions, arrival time differences, thicknesses of the structure, and specimen structural variations. Such topics as Guided wave physical and theoretical considerations, Ultrasonic Guided wave accomplishments, and enhanced AE by considering various guided wave concepts are discussed. The topic of Acousto-Ultrasonics and its impact on guided wave understanding is also reviewed. This paper illustrates how principles in Ultrasonic Guided waves can be applied to Acoustic Emission. Besides basic issues, Acoustic Emission enhancement possibilities are based on recent studies of Ultrasonic Guided Waves and the use of Shear Horizontal guided waves in Acoustic Emission along with an omni-directional shear horizontal wave transducer. Editor's note: Joseph L. Rose, PhD, is the recipient of the 2021 ASNT Research Recognition for Sustained Excellence. Rose presented on Guided Wave Studies for Enhanced Acoustic Emission Inspection during the ASNT Research Symposium which was held 27-29 April 2021.

Automated summary

This paper discusses the fundamental elements of wave mechanics in relation to Acoustic Emission analysis in Nondestructive Evaluation and Structural Health monitoring, with emphasis on Ultrasonic Guided Waves generated by elastic wave emissions from defect sources in structures. The paper also explores physical and theoretical considerations of guided waves, achievements in Ultrasonic Guided Waves, and enhancements in Acoustic Emission by considering various guided wave concepts.