Improving the Imaging Performance of Novel Ultrasonic Arrays

Abstract

Ultrasonic arrays have been a common feature of ultrasonic non-destructive evaluation in academia for many years. Their prevalence in industry has also recently increased. As ultrasonic arrays have become more common, so have the number of novel ultrasonic arrays. These novel arrays have come from industrial companies driving the production of arrays with higher numbers of elements and from the academic community applying concepts from ultrasonic arrays to less common methods of ultrasonic testing. In this work, the imaging performance of two very different novel ultrasonic arrays have been improved.

Firstly, the total focusing method has been adapted for use with row-column addressed arrays. The algorithm has been demonstrated experimentally to improve the detectability and sizing of simulated defects, with a less-than-half-wavelength conical bottom hole being successfully detected and the sizing accuracy being increased by an order of magnitude.

Secondly, diffuse field reconstruction techniques have been demonstrated to increase the data collection speed of laser ultrasonic arrays by two orders of magnitude. The techniques used have created an array of laser interferometers which appear as if they transmit and receive ultrasound, producing images with similar properties to conventional ultrasonic arrays.

Date of Award	26 Nov 2020
Original language	English
Awarding Institution	University of Bristol
Supervisor	David A Hallam (Supervisor), Robert A Smith (Supervisor) & Paul D Wilcox (Supervisor)