Session: 04-01: Emerging Techniques & Technology

Paper Number: 138298

138298 - Passive Measurement of Remaining Wall Thickness Using Acoustic Emission Excitation 

Abstract: 

Erosion-Corrosion is a combined mechanical-chemical process that occurs when particles suspended in a fluid flow abrades the inside surface of a pipeline. It is particularly problematic for the oil industry as the damage mechanism can occur rapidly and is difficult to predict. To mitigate this acoustic emission transducers are installed to detect the presence of particles impacting the inside surface of the pipeline; when the acoustic emission reaches an unacceptable level the fluid flow is reduced or stopped. While the acoustic emission transducers detect the presence of the particles that are a prerequisite for erosion-corrosion, they do not directly monitor corrosion. It would therefore be an attractive proposition to use the existing extensive network of acoustic emission transducers to also monitor wall thickness. The challenge is that acoustic emission monitoring systems are passive; they are not equipped with excitation  capability. It has been realised that valuable ultrasonic information can be derived from autocorrelating acoustical noise. Specifically, the autocorrelation function of a diffuse acoustic field is equal to the Green’s function of the body. Consequently, a band-pass filtered autocorrelation function of an acoustical noise measurement will be equal to an active measurement of the same bandwidth. The present study will show that measurements of wall thickness can be achieved by autocorrelating passive acoustic emission signals. Two measurement modalities will be presented: a) time-of-flight measurements and b) resonant ultrasound spectroscopy measurements to be utilized for thin wall thickness measurements.

Presenting Author: Joseph Corcoran University of Cincinnati

Presenting Author Biography: Joseph Corcoran joined the University of Cincinnati as Associate Professor in 2020. He received his MEng and PhD degrees in Mechanical Engineering from Imperial College, where he maintains an Honorary Lecturer position. His research interests lie in the development of Structural Health Monitoring (SHM) systems and ‘smart’ structural integrity assessments through the Digital Twin concept. His research covers electromagnetic and ultrasonic methods, analytical and experimental techniques and the development of both hardware and software solutions.

Authors:

Natalie Reed University of Cincinnati
Joseph Corcoran University of Cincinnati