The use of circumferential guided waves to monitor axial cracks in pipes
Author(s)
Cawley, Peter
Rodgers, Euan
Mariani, stefano
Type
Journal Article
Abstract
Guided wave testing is in routine use to detect corrosion, particularly in the oil and gas sector, but the detection of axial cracking is difficult using the axially propagating waves commonly used for corrosion detection. This paper presents a novel guided wave monitoring technique for the detection of axial cracking in piping. Circumferential SH0 waves, travelling around the circumference were used in a monitoring configuration to detect axial defects in a 6” schedule 80 steel pipe. Finite Element Analysis showed that both the defect reflection and the decline in the transmitted SH0 wave can be used for defect detection. Baseline subtraction was utilised to produce residual signals that can be better analysed for small defect reflections. The RMS of the residual signal after baseline subtraction was found to be the most satisfactory means of monitoring defect progression. An amplification effect was identified where the residual signal is compounded by continued interaction with the defect on each revolution of the incident wave. The finite element predictions were validated by an experiment in which an EDM notch was grown in four stages. Temperature compensation using Location Specific Temperature Compensation was applied to the experimental data, allowing residuals to be compared for a ~10oC temperature swing over a monitoring period of over 2 months. It was determined that a 10mm long (~23% of wavelength), 5mm deep (~45% of the wall thickness) defect at an axial offset from the line of the transducers of 1.5 wavelengths (65mm) would be readily detectable with a very high Probability of Detection and virtually no chance of a false call. Therefore, this novel guided wave monitoring system for axial crack detection is likely to be attractive for
applications in a range of industries for its sensitivity to axial cracking combined with large coverage from a single transducer location.
applications in a range of industries for its sensitivity to axial cracking combined with large coverage from a single transducer location.
Date Issued
2023-07-01
Date Acceptance
2022-09-13
Citation
Structural Health Monitoring: an international journal, 2023, 22 (4), pp.2609-2625
ISSN
1475-9217
Publisher
SAGE Publications
Start Page
2609
End Page
2625
Journal / Book Title
Structural Health Monitoring: an international journal
Volume
22
Issue
4
Copyright Statement
© The Author(s) 2022. This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage). Request permissions for this article.
License URL
Publication Status
Published
Date Publish Online
2022-11-09