Guided Waves Tomography and Image Fusion for Damage Identification in Pipes

2011 ◽  
Vol 94-96 ◽  
pp. 1585-1589 ◽  
Author(s):  
Hai Yan Zhang ◽  
Jian Bo Yu ◽  
Xian Hua Chen
Keyword(s):  
Image Fusion ◽  
Guided Waves ◽  
Damage Identification ◽  
Tomographic Reconstruction ◽  
Element Model ◽  
Guided Wave ◽  
Reconstruction Technique ◽  
Arrival Times ◽  
Iterative Reconstruction Technique ◽  
Incomplete Datasets

The detection of localized defects such as cracks and corrosion in pipes using guided waves has been shown to be an effective nondestructive evaluation technique for structural health monitoring (SHM). Cross borehole tomography in seismology is introduced into the guided wave inspection of a pipe when the pipe is considered as an unwrapped plate. Guided waves propagating in pipe with a crack defect are simulated using the finite element model and the arrival times for the fastest modes are extracted and sent to the tomographic algorithm. The tomographic reconstruction is based on the simultaneous iterative reconstruction technique (SIRT). For some cylindrical shell geometries such as stacked storage tanks, access to the entire circumference of the structure could be impractical or even impossible, three different image fusion techniques are used to enhance the image equality reconstructed from the incomplete datasets. The results show that the defect is more pronounced after imaging fusion.

scholarly journals Comparison of Ultrasonic Non-Contact Air-Coupled Techniques for Characterization of Impact-Type Defects in Pultruded GFRP Composites

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1058
Author(s):  
Aadhik Asokkumar ◽  
Elena Jasiūnienė ◽  
Renaldas Raišutis ◽  
Rymantas Jonas Kažys
Keyword(s):  
Guided Waves ◽  
Lamb Waves ◽  
Tomographic Reconstruction ◽  
Guided Wave ◽  
Reconstruction Technique ◽  
Bulk Wave ◽  
Glass Fiber Reinforced Plastic ◽  
Ultrasonic Guided Wave ◽  
Single Side ◽  
Numerical Finite Element

This article compares different air-coupled ultrasonic testing methods to characterize impact-type defects in a pultruded quasi-isotropic glass fiber-reinforced plastic (GFRP) composite plate. Using the air-coupled transducers, comparisons among three methods were performed, namely, bulk-wave through transmission, single-side access using guided waves, and ultrasonic-guided wave tomography. The air coupled through transmission technique can determine the size and shape of impact-type defects with a higher resolution, but with the consequence of time consumption and, more importantly, the necessity of access to both sides of the sample. The guided wave technique on the other hand, allows a single-side inspection and is relatively fast. It can be used to determine the size of the defect using ultrasonic B-scan, but the exact shape of the defect will be compromised. Thus, in this article, to determine the shape of the defect, application of the parallel beam tomographic reconstruction technique using guided Lamb waves is demonstrated. Furthermore, a numerical finite element simulation was performed to study the effects of guided wave propagation in the composite sample and interaction with the internal defect. Lastly, the results from the experiments of different techniques were compared according to possibilities of defect sizing and determination of its shape.

Contribution of Lamb wave modes in the formation of higher order modes cluster (HOMC) guided waves

2021 ◽  
pp. 095440622110424
Author(s):  
Z Abbasi ◽  
F Honarvar
Keyword(s):  
Finite Element ◽  
Wave Packet ◽  
Lamb Wave ◽  
Guided Waves ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Cross Sectional ◽  
Higher Order Modes ◽  
Wave Modes

In recent years, Higher Order Modes Cluster (HOMC) guided waves have been considered for ultrasonic testing of plates and pipes. HOMC guided waves consist of higher order Lamb wave modes that travel together as a single nondispersive wave packet. The objective of this paper is to investigate the effect of frequency-thickness value on the contribution of Lamb wave modes in an HOMC guided wave. This is an important issue that has not been thoroughly investigated before. The contribution of each Lamb wave mode in an HOMC guided wave is studied by using a two-dimensional finite element model. The level of contribution of various Lamb wave modes to the wave cluster is verified by using a 2D FFT analysis. The results show that by increasing the frequency-thickness value, the order of contributing modes in the HOMC wave packet increases. The number of modes that comprise a cluster also increases up to a specific frequency-thickness value and then it starts to decrease. Plotting of the cross-sectional displacement patterns along the HOMC guided wave paths confirms the shifting of dominant modes from lower to higher order modes with increase of frequency-thickness value. Experimental measurements conducted on a mild steel plate are used to verify the finite element simulations. The experimental results are found to be in good agreement with simulations and confirm the changes observed in the level of contribution of Lamb wave modes in a wave cluster by changing the frequency-thickness value.

scholarly journals Development of Ultrasonic Guided Wave Transducer for Monitoring of High Temperature Pipelines

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5443 ◽  
Author(s):  
Anurag Dhutti ◽  
Saiful Asmin Tumin ◽  
Wamadeva Balachandran ◽  
Jamil Kanfoud ◽  
Tat-Hean Gan
Keyword(s):  
High Temperature ◽  
Guided Waves ◽  
Elevated Temperatures ◽  
Element Model ◽  
Wave Mode ◽  
Guided Wave ◽  
Electromechanical Impedance ◽  
Active Sensor ◽  
Ultrasonic Guided Wave ◽  
Modes Of Vibration

High-temperature (HT) ultrasonic transducers are of increasing interest for structural health monitoring (SHM) of structures operating in harsh environments. This article focuses on the development of an HT piezoelectric wafer active sensor (HT-PWAS) for SHM of HT pipelines using ultrasonic guided waves. The PWAS was fabricated using Y-cut gallium phosphate (GaPO4) to produce a torsional guided wave mode on pipes operating at temperatures up to 600 °C. A number of confidence-building tests on the PWAS were carried out. HT electromechanical impedance (EMI) spectroscopy was performed to characterise piezoelectric properties at elevated temperatures and over long periods of time (>1000 h). Laser Doppler vibrometry (LDV) was used to verify the modes of vibration. A finite element model of GaPO4 PWAS was developed to model the electromechanical behaviour of the PWAS and the effect of increasing temperatures, and it was validated using EMI and LDV experimental data. This study demonstrates the application of GaPO4 for guided-wave SHM of pipelines and presents a model that can be used to evaluate different transducer designs for HT applications.

Lamb wave-based experimental and numerical studies for detection and sizing of corrosion damage in metallic plates

2018 ◽  
Vol 233 (6) ◽  
pp. 2107-2120 ◽  
Author(s):  
Adel Sedaghati ◽  
Farhang Honarvar ◽  
Anthony N Sinclair
Keyword(s):  
Guided Waves ◽  
Lamb Waves ◽  
Corrosion Damage ◽  
Element Model ◽  
Thin Plates ◽  
Aluminum Plate ◽  
Arrival Times ◽  
Numerical Studies ◽  
Corrosion Defects

Lamb waves are ultrasonic-guided waves with applications in inspection and monitoring of plate-like structures. These waves can be used for detecting, locating, and sizing of defects. In this paper, a new method is proposed for in situ measurement of the location and size of circle-like corrosion defects in thin plates. A novel technique for omnidirectional generation of Lamb waves is also proposed. The probe is placed on at least three different points around the defect and the arrival times of reflected echoes are measured. An algorithm then estimates the location and size of the defect based on the arrival times of reflected echoes. A finite element model is also developed for modeling the process and studying various aspects of the method. The proposed method is then tested on an aluminum plate. The center location and radius of a 5-mm hole in a 0.5-mm thick aluminum plate is estimated with uncertainties of ±1 mm (1%) and ±0.25 mm (5%), respectively. Various aspects of the proposed method are discussed, and uncertainties in measurements are estimated. Effectiveness of the proposed method is also assessed by sizing actual corrosion defects. The proposed method is fast, flexible, and portable and shows better accuracy in comparison to similar existing methods.

scholarly journals Elbow Damage Identification Technique Based on Sparse Inversion Image Reconstruction

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1786
Author(s):  
Yu Wang ◽  
Xueyi Li
Keyword(s):  
Oil And Gas ◽  
Damage Identification ◽  
Sound Field ◽  
Guided Wave ◽  
Inversion Method ◽  
Reconstruction Technique ◽  
Fast Marching ◽  
Pipe Elbow ◽  
Identification Technique ◽  
Sparse Inversion

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.

Modeling guided waves to constrain the velocity structure of the oceanic crust in the subduction zone of eastern Alaska

2020 ◽  
Author(s):  
Xiaoyu Guan ◽  
Yuanze Zhou ◽  
Takashi Furumura
Keyword(s):  
Subduction Zone ◽  
Oceanic Crust ◽  
High Frequency ◽  
Subduction Zones ◽  
Guided Waves ◽  
Velocity Structure ◽  
Guided Wave ◽  
S Wave ◽  
Arrival Times ◽  
Velocity Models

<p>Fitting subduction zone guided waves with synthetics is an ideal choice for studying the velocity structure of the oceanic crust. After an earthquake occurs in subduction zones, seismic waves can be trapped in the low-velocity oceanic crust and propagated as guided waves. The arrival time and frequency characteristics of the guided waves can be used to image the velocity structure of the oceanic crust. The analysis and modeling based on guided wave observations provide a rare opportunity to understand the velocity structure of the oceanic crust and the variations in oceanic crustal materials during the subduction process.</p><p>High-frequency guided waves have been observed in the subduction zone of eastern Alaska. On several sections, observed seismograms recorded by seismic stations show low-frequency (<2Hz) onsets ahead of the main high-frequency (>2Hz) guided waves. Differences in the arrival times and dispersion characteristics of seismic phases are related to the velocity structure of the oceanic crust, and the characteristics of coda waves are related to the distribution of elongated scatters in the oceanic crust. Through fitting the observed broadband waveforms and synthetics modeled with the 2-D FDM (Finite Difference Method), we obtain the preferred oceanic crustal velocity models for several sections in the subduction zone of eastern Alaska. The preferred models can explain the seismic phase arrival times, dispersions, and coda characteristics in the observed waveforms. With the obtained P- and S- wave models of velocity structures on several sections, the material compositions they represent are deduced, and the variations of oceanic crustal materials during subducting can be understood. This provides new evidence for studying the details of the subduction process in the subduction zone of eastern Alaska.</p>

The diminishing residual matrices method for surface-consistent statics — A review

Geophysics ◽  
2017 ◽  
Vol 82 (4) ◽  
pp. V257-V274
Author(s):  
Necati Gülünay
Keyword(s):  
Synthetic Data ◽  
Reconstruction Technique ◽  
Data Set ◽  
Arrival Times ◽  
Long Wavelength ◽  
Iterative Reconstruction Technique ◽  
Land Survey ◽  
First Arrival ◽  
Waveform Distortions ◽  
The Individual

The diminishing residual matrices (DRM) method can be used to surface-consistently decompose individual trace statics into source and receiver components. The statics to be decomposed may either be first-arrival times after the application of linear moveout associated with a consistent refractor as used in refraction statics or residual statics obtained by crosscorrelating individual traces with corresponding model traces (known as pilot traces) at the same common-midpoint (CMP) location. The DRM method is an iterative process like the well-known Gauss-Seidel (GS) method, but it uses only source and receiver terms. The DRM method differs from the GS method in that half of the average common shot and receiver terms are subtracted simultaneously from the observations at each iteration. DRM makes the under-constrained statics problem a constrained one by implicitly adding a new constraint, the equality of the contribution of shots and receivers to the solution. The average of the shot statics and the average of the receiver statics are equal in the DRM solution. The solution has the smallest difference between shot and receiver statics profiles when the number of shots and the number of receivers in the data are equal. In this case, it is also the smallest norm solution. The DRM method can be derived from the well-known simultaneous iterative reconstruction technique. Simple numerical tests as well as results obtained with a synthetic data set containing only the field statics verify that the DRM solution is the same as the linear inverse theory solution. Both algorithms can solve for the long-wavelength component of the statics if the individual picks contain them. Yet DRM method is much faster. Application of the method to the normal moveout-corrected CMP gathers on a 3D land survey for residual statics calculation found that pick-decompose-apply-stack stages of the DRM method need to be iterated. These iterations are needed because of time and waveform distortions of the pilot traces due to the individual trace statics. The distortions lessen at every external DRM iteration.

Guided Wave Tomography Using Simultaneous Iterative Reconstruction Technique Improved by Genetic Algorithm

2011 ◽  
Vol 94-96 ◽  
pp. 1607-1610 ◽  
Author(s):  
Hai Yan Zhang ◽  
Jian Bo Yu ◽  
Xian Hua Chen
Keyword(s):  
Genetic Algorithm ◽  
Nondestructive Evaluation ◽  
Iterative Reconstruction ◽  
Guided Wave ◽  
Reconstruction Technique ◽  
Improve Image Quality ◽  
Iterative Reconstruction Technique ◽  
Wave Tomography ◽  
Simultaneous Iterative Reconstruction Technique

Guided wave tomography has shown great potential for quantitative nondestructive evaluation in structural health monitoring. An improved simultaneous iterative reconstruction technique (SIRT) combining genetic algorithm (GA) is presented in order to improve image quality of guided wave tomography. The simulated reconstructed images of flawed plate and pipe using usual SIRT and improved SIRT methods have been compared quantitatively and qualitatively.

Ultrasonic Circumferential Guided Wave for Pitting-Type Corrosion Imaging at Inaccessible Pipe-Support Locations

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. Shivaraj ◽  
Krishnan Balasubramaniam ◽  
C. V. Krishnamurthy ◽  
R. Wadhwan
Keyword(s):  
Guided Waves ◽  
Pipe Wall ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Structural Layout ◽  
Ultrasonic Guided Wave ◽  
Experimental Parameters ◽  
Data Acquisition Card ◽  
Pulse Echo

A higher order cylindrically guided ultrasonic wave was used for the detection and sizing of hidden pitting-type corrosion in the hidden crevice regions (between the pipe and the pipe supports) without lifting or disturbing the structural layout arrangement of the pipelines. The higher order circumferential guided waves were generated using a piezoelectric crystal based transducer, located at the accessible top region of the pipes, in a pulse-echo mode. By studying the experimental parameters such as dispersion, particle displacement, and wavelength of the ultrasonic guided wave modes, an appropriate higher order mode was selected for excitation using an appropriately designed acrylic angle wedge that conforms to the pipe’s outer curvature. A manual pipe crawler was designed with a provision for holding the wedge, and the essential hardware such as data acquisition card, encoder, etc., was integrated with the system so that the corrosion was mapped in real time during the scanning of the pipes. The system was validated on pipes ranging from 6in.to24in. outer diameters of wall thicknesses up to 12mm, by mapping defects as small as 1.5mm diameter and 25% penetration wall thickness. A 2D finite element model using ABAQUS® was used to understand the wave propagation in pipe wall and its interaction with pinhole-type defects.

scholarly journals Damage Detection in Flat Panels by Guided Waves Based Artificial Neural Network Trained through Finite Element Method

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7602
Author(s):  
Donato Perfetto ◽  
Alessandro De Luca ◽  
Marco Perfetto ◽  
Giuseppe Lamanna ◽  
Francesco Caputo
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Damage Identification ◽  
Analytical Data ◽  
Guided Wave ◽  
Fe Model ◽  
Promising Tool ◽  
Artificial Neural ◽  
Element Method

Artificial Neural Networks (ANNs) have rapidly emerged as a promising tool to solve damage identification and localization problem, according to a Structural Health Monitoring approach. Finite Element (FE) Analysis can be extremely helpful, especially for reducing the laborious experimental campaign costs for the ANN development and training phases. The aim of the present work is to propose a guided wave-based ANN, developed through the use of the Finite Element Method, to determine the position of damages. The paper first addresses the development and assessment of the modeling technique. The FE model accuracy was proven through the comparison of the predicted results with experimental and analytical data. Then, the ANN was developed and trained on an aluminum plate and subsequently verified in a composite plate, as well as under different damage configurations. According to the results herein proposed, the ANN allowed to detect and localize damages with a high level of accuracy in all cases of study.

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