Acoustic formulation of elastic guided wave propagation and scattering in curved tubular structures

Brath, Alex J.; Simonetti, F.; Nagy, Péter B.; Instanes, Geir

doi:10.1109/tuffc.2014.2973

Cited by 20 publications

(17 citation statements)

References 29 publications

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“…A simplified forward model was built by unwrapping the pipes to a plate with the assumption that the wall thickness of the pipe was small relative to its diameter [39]. According to tomographic imaging principle and Fermat's theorem, the approach introduced in [40] established the heterogeneous anisotropic sound field model to transform the dual mapping of the elbow 3-D model to the 2-D model in physical structure as well acoustic characteristics.…”

Section: -D Forward Modelmentioning

confidence: 99%

Elbow Damage Identification Technique Based on Sparse Inversion Image Reconstruction

Wang

2020

Materials

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Continuous monitoring for defects in oil and gas pipelines is important for leakage prevention. This paper proposes a new kind of pipe elbow damage identification technique, which consists of three processes. First, piezoelectric sensors evenly arranged along the circumference of the pipeline in the turn generated ultrasonic guided wave signals in the elbow. Then, the wavefront flight time at each grid node in the known sound field were computed using the fast-marching algorithm. Finally, an elbow wall thickness map reconstruction technique based on the sparse inversion method was proposed to identify elbow defects. Compared with the traditional elbow defect identification technology, this technology can not only detect the existence of the defect but also accurately locate the defect position.

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Section: -D Forward Modelmentioning

confidence: 99%

Elbow Damage Identification Technique Based on Sparse Inversion Image Reconstruction

Wang

2020

Materials

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“…In the experimental setup considered here, which is illustrated in Figure 2, this is not the case, as the artificial defect is not surrounded by sensors, but rather two ring arrays, one on either side of the defect. By unwrapping the pipe into a flat plate, disregarding the pipe wall curvature [20]- [22], the defect then lies between two parallel linear arrays and it is clear that the full view configuration does not apply.…”

Section: Limited-view Configuration and Viscit Algorithmmentioning

confidence: 99%

Experimental Studies of the Inspection of Areas With Restricted Access Using A0 Lamb Wave Tomography

Seher

Huthwaite

Lowe

2016

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Corrosion damage in inaccessible regions presents a significant challenge to the petrochemical industry, and determining the remaining wall thickness is important to establish the remaining service life. Guided wave tomography is one solution to this and involves transmitting Lamb waves through the area of interest and subsequently using the received signals to reconstruct a thickness map of the remaining wall thickness. This avoids the need to access all points on the surface, making the technique well suited to inspection for areas with restricted access. The influence of these areas onto the ability to detect and size surface conditions, such as corrosion damage, using guided wave tomography is assessed. For that, a guided wave tomography system is employed, which is based on low frequency A0 Lamb waves that are excited and detected with two arrays of electromagnetic acoustic transducers (EMATs). Two different defect depths are considered with different contrasts relative to the nominal wall thickness, both of which are smoothly varying and welldefined. The influence of areas with restricted surface access, support locations, pipe clamps and STOPAQ(R) coatings, are experimentally tested, and their influence assessed through comparison to a baseline reconstruction without the respective restriction in place, demonstrating only a small influence on the detected value of the remaining wall thickness.

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“…Therefore, if a reconstruction of velocity is produced, this can subsequently be converted back to thickness; an evaluation of the accuracy of the assumptions made in this approach is given in [26]. While the Lamb waves are defined for flat plates, rather than curved pipe walls, in this paper the wall curvature will be considered negligible; this can be shown to be a valid assumption if the thickness is less than around 10% of the radius [27], [28], which is the case for the majority of pipes of interest.…”

Section: A Backgroundmentioning

confidence: 99%

Robust helical path separation for thickness mapping of pipes by guided wave tomography

Huthwaite

Seher

2015

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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The 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 which enables 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 either side of the inspected region, and due to the cylindrical nature of the pipe, waves are able to travel in an inifinite 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. Index Termstomography, guided wave, Lamb wave, signal separation, helical paths Manuscript received XXXXXXX X, XXXX.All authors are with the

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Acoustic formulation of elastic guided wave propagation and scattering in curved tubular structures

Cited by 20 publications

References 29 publications

Elbow Damage Identification Technique Based on Sparse Inversion Image Reconstruction

Elbow Damage Identification Technique Based on Sparse Inversion Image Reconstruction

Experimental Studies of the Inspection of Areas With Restricted Access Using A0 Lamb Wave Tomography

Robust helical path separation for thickness mapping of pipes by guided wave tomography

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