Optimal Matched Filter Design for Ultrasonic NDE of Coarse Grain Materials

Li, M. and Hayward, G. (2016) Optimal Matched Filter Design for Ultrasonic NDE of Coarse Grain Materials. In: 42nd Annual Review of Progress in Quantitative Nondestructive Evaluation: Incorporating the 6th European-American Workshop on Reliability of NDE, Minneapolis, MN, USA, 26–31 July 2015, 020011. (doi:10.1063/1.4940457)

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Abstract

Coarse grain materials are widely used in a variety of key industrial sectors like energy, oil and gas, and aerospace due to their attractive properties. However, when these materials are inspected using ultrasound, the flaw echoes are usually contaminated by high-level, correlated grain noise originating from the material microstructures, which is time-invariant and demonstrates similar spectral characteristics as flaw signals. As a result, the reliable inspection of such materials is highly challenging. In this paper, we present a method for reliable ultrasonic non-destructive evaluation (NDE) of coarse grain materials using matched filters, where the filter is designed to approximate and match the unknown defect echoes, and a particle swarm optimization (PSO) paradigm is employed to search for the optimal parameters in the filter response with an objective to maximise the output signal-to-noise ratio (SNR). Experiments with a 128-element 5MHz transducer array on mild steel and INCONEL Alloy 617 samples are conducted, and the results confirm that the SNR of the images is improved by about 10-20 dB if the optimized matched filter is applied to all the A-scan waveforms prior to image formation. Furthermore, the matched filter can be implemented in real-time with low extra computational cost.

Item Type:Conference Proceedings
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Li, Dr David
Authors: Li, M., and Hayward, G.
College/School:College of Science and Engineering
ISSN:0094-243X
Copyright Holders:Copyright © 2016 AIP Publishing LLC
Publisher Policy:Reproduced in accordance with the copyright policy of the publisher

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