Next Article in Journal
A Real Time and Lossless Encoding Scheme for Patch Electrocardiogram Monitors
Previous Article in Journal
Design and Application of a Standalone Hybrid Wind–Solar System for Automatic Observation Systems Used in the Polar Region
Previous Article in Special Issue
Enhancement of Ultrasonic Guided Wave Signals Using a Split-Spectrum Processing Method
Article Menu

Export Article

Open AccessArticle
Appl. Sci. 2018, 8(12), 2378; https://doi.org/10.3390/app8122378

Detection of Defects Using Spatial Variances of Guided-Wave Modes in Testing of Pipes

1
Department of Electronic and Computer Engineering, Brunel University London, Uxbridge UB8 3PH, UK
2
NSIRC, Granta Park, Cambridge CB21 6AL, UK
3
TWI, Granta Park, Cambridge CB21 6AL, UK
*
Author to whom correspondence should be addressed.
Received: 19 October 2018 / Revised: 13 November 2018 / Accepted: 19 November 2018 / Published: 24 November 2018
(This article belongs to the Special Issue Ultrasonic Guided Waves)
Full-Text   |   PDF [7694 KB, uploaded 24 November 2018]   |  

Abstract

In the past decade, guided-wave testing has attracted the attention of the non-destructive testing industry for pipeline inspections. This technology enables the long-range assessment of pipelines’ integrity, which significantly reduces the expenditure of testing in terms of cost and time. Guided-wave testing collars consist of several linearly placed arrays of transducers around the circumference of the pipe, which are called rings, and can generate unidirectional axisymmetric elastic waves. The current propagation routine of the device generates a single time-domain signal by doing a phase-delayed summation of each array element. The segments where the energy of the signal is above the local noise region are reported as anomalies by the inspectors. Nonetheless, the main goal of guided-wave inspection is the detection of axisymmetric waves generated by the features within the pipes. In this paper, instead of processing a single signal obtained from the general propagation routine, we propose to process signals that are directly obtained from all of the array elements. We designed an axisymmetric wave detection algorithm, which is validated by laboratory trials on real-pipe data with two defects on different locations with varying cross-sectional area (CSA) sizes of 2% and 3% for the first defect, and 4% and 5% for the second defect. The results enabled the detection of defects with low signal-to-noise ratios (SNR), which were almost buried in the noise level. These results are reported with regard to the three different developed methods with varying excitation frequencies of 30 kHz, 34 kHz, and 37 kHz. The tests demonstrated the advantage of using the information received from all of the elements rather than a single signal. View Full-Text
Keywords: signal processing; defect detection; spatial domain; array analysis; pipeline inspection; ultrasonic guided waves (UGWs) signal processing; defect detection; spatial domain; array analysis; pipeline inspection; ultrasonic guided waves (UGWs)
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Mahal, H.N.; Yang, K.; Nandi, A.K. Detection of Defects Using Spatial Variances of Guided-Wave Modes in Testing of Pipes. Appl. Sci. 2018, 8, 2378.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Appl. Sci. EISSN 2076-3417 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top