Robust Helical Path Separation for Thickness Mapping of Pipes by Guided Wave Tomography
File(s)
Accepted version
Author(s)
Huthwaite, P
Seher, M
Type
Journal Article
Abstract
Pipe wall loss caused by corrosion can be quantified
across an area by transmitting guided Lamb waves through
the region and measuring the resulting signals. Typically the
dispersive relationship for these waves, which means that
wave velocity is a known function of thickness, is exploited,
enabling the wall thickness to be determined from a velocity
reconstruction. The accuracy and quality of this reconstruction
is commonly limited by the angle of view available from the
transducer arrays. These arrays are often attached as a pair
of ring arrays on either side of the inspected region, and due
to the cylindrical nature of the pipe, waves are able to travel
in an infinite number of helical paths between any two transducers.
The first arrivals can be separated relatively easily by
time gating, but by using just these components the angle of
view is severely restricted. To improve the viewing angle, it is
necessary to separate the wavepackets. This paper provides an
outline of a separation approach: initially the waves are backpropagated
to their source to align the different signals, then a
filtering technique is applied to select the desired components.
The technique is applied to experimental data and demonstrated
to robustly separate the signals
across an area by transmitting guided Lamb waves through
the region and measuring the resulting signals. Typically the
dispersive relationship for these waves, which means that
wave velocity is a known function of thickness, is exploited,
enabling the wall thickness to be determined from a velocity
reconstruction. The accuracy and quality of this reconstruction
is commonly limited by the angle of view available from the
transducer arrays. These arrays are often attached as a pair
of ring arrays on either side of the inspected region, and due
to the cylindrical nature of the pipe, waves are able to travel
in an infinite number of helical paths between any two transducers.
The first arrivals can be separated relatively easily by
time gating, but by using just these components the angle of
view is severely restricted. To improve the viewing angle, it is
necessary to separate the wavepackets. This paper provides an
outline of a separation approach: initially the waves are backpropagated
to their source to align the different signals, then a
filtering technique is applied to select the desired components.
The technique is applied to experimental data and demonstrated
to robustly separate the signals
Date Issued
2015-05-01
Date Acceptance
2015-01-20
Citation
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control, 2015, 62 (5), pp.927-938
ISSN
1525-8955
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Start Page
927
End Page
938
Journal / Book Title
IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control
Volume
62
Issue
5
Copyright Statement
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Subjects
Science & Technology
Technology
Acoustics
Engineering, Electrical & Electronic
Engineering
TRAVEL-TIME TOMOGRAPHY
FLEXURAL INHOMOGENEITIES
DIFFRACTION TOMOGRAPHY
CORROSION
PLATES
Publication Status
Published