Damage Identification of Cracked Pipes Based on Reflection Characteristics of Guided Waves

2011 ◽  
Vol 94-96 ◽  
pp. 623-626
Author(s):  
Xiong Wei Hu ◽  
Xin Feng ◽  
Jing Zhou
Keyword(s):  
Guided Waves ◽  
Damage Identification ◽  
Mode Conversion ◽  
Quantitative Relationship ◽  
Crack Size ◽  
Guided Wave ◽  
Radial Depth ◽  
Good Potential ◽  
Novel Method ◽  
Reflection Characteristics

A methodology of damage identification for the circumferentially cracked pipe is presented by using the quantitative relationship between crack size and reflection characteristics of guided waves. Firstly, the reflection characteristics and mode conversion behavior were theoretically studied by the 3-D finite element (FE) analysis. It is found that the reflection coefficients (RCs) of longitudinal L(0,2) and F(1,3) modes quantitatively is related to the circumferential length and radial depth of the crack. Then we present a novel method to quantitatively identify the crack. The feasibility of the proposed method was numerically investigated. The method only requires the longitudinal excitation mode of guided wave in the pipe, which shows the good potential for real application or in-situ damage monitoring. Introduction

scholarly journals Longitudinal Guided Wave Inspection of Small-Diameter Elbowed Steel Tubes with a Novel Squirrel-Cage Magnetostrictive Sensor

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yao Liu ◽  
Xiucheng Liu ◽  
Chehua Yang ◽  
Wenxin Guo ◽  
Bin Wu ◽  
...  
Keyword(s):  
Finite Element ◽  
Guided Waves ◽  
Mode Conversion ◽  
Small Diameter ◽  
Longitudinal Mode ◽  
Guided Wave ◽  
Wall Defect ◽  
Squirrel Cage ◽  
Simulation Results ◽  
Magnetostrictive Sensor

In the study, ultrasonic longitudinal mode guided waves were employed to detect defects in elbowed tubes (without welds) with a diameter of 10 mm. Finite element simulation results highlighted that the emitted L(0,1) mode guided waves experienced strong reflection and mode conversion at the elbow region to generate F(1,1) mode, followed by slow and weak F(2,1) mode. The guided wave reflected from the elbow with a through-wall defect was manifested as two overlapped wave packets, which were good indicators of a defective elbow. To conduct L(0,1) mode guided waves inspection on the small-diameter elbowed tubes, a novel tailored squirrel-cage magnetostrictive sensor was employed in the experiment. The new sensor employed the configuration of segmental iron-cobalt strips and small-size permanent magnet arrays. The entire sensor is composed of two identical C-shaped sensor elements and can be recycled and installed conveniently. Experimental results obtained from healthy and defective tubes were consistent with the conclusions obtained from finite element simulations. An artificial through-wall defect at the elbow and a notch defect at the straight part of the tube could be simultaneously detected by L(0,1) mode guided waves through comparing experimental signals with simulation results.

Circumference Damage Identification in a Pipe Using Mode Conversion of Longitudinal Guided Wave

2013 ◽  
Vol 395-396 ◽  
pp. 787-791
Author(s):  
Jing Wu ◽  
Wei Wei Zhang
Keyword(s):  
Damage Detection ◽  
Damage Identification ◽  
Mode Conversion ◽  
Guided Wave ◽  
Symmetric Mode ◽  
Axially Symmetric ◽  
Mode Transformation ◽  
Damage Location

This paper aims to develop a method to identify the damage location in circumference direction of a pipe using mode transformation of longitudinal guided wave. The corrosion-like damage in bimetal pipe is considered. Case study that damage detection for a bimetal pipe is used to show the validity and advantage of the proposed method. It can be found that the axially symmetric mode guided wave encounter the damage and the three modes were received in reflection. The damage location in circumferential directions could be identified by conversed modes measured at one position. The simulation shows a good performance.

A Wall Thinning Detection and Quantification Based on Guided Wave Mode Conversion Features

2006 ◽  
Vol 321-323 ◽  
pp. 795-798 ◽  
Author(s):  
Youn Ho Cho ◽  
Won Deok Oh ◽  
Joon Hyun Lee
Keyword(s):  
Long Range ◽  
Guided Waves ◽  
Velocity Dispersion ◽  
Mode Conversion ◽  
Group Velocity Dispersion ◽  
Wave Mode ◽  
Guided Wave ◽  
Wall Thinning ◽  
Theoretical Analyses ◽  
Data Calibration

This study presents a feasibility of using guided waves for a long-range inspection of pipe through investigation of mode conversion and scattering pattern from edge and wall-thinning in a steel pipe. Phase and group velocity dispersion curves for reference modes of pipes are illustrated for theoretical analyses. Predicted modes could be successfully generated by controlling frequency, receiver angle and wavelength. The dispersive characteristics of the modes from and edge wall-thinning are compared and analyzed respectively. The mode conversion characteristics are distinct depending on dispersive pattern of modes. Experimental feasibility study on the guided waves was carried out to explore wall thinning part in pipe for data calibration of a long range pipe monitoring by comb transducer and laser.

scholarly journals Quantitative mapping of thickness variations along a ray path using geometrical full waveform inversion and guided wave mode conversion

2022 ◽  
Vol 478 (2257) ◽  
Author(s):  
Peng Zuo ◽  
Peter Huthwaite
Keyword(s):  
Guided Waves ◽  
Mode Conversion ◽  
Waveform Inversion ◽  
Guided Wave ◽  
Direct Access ◽  
Thickness Variation ◽  
Full Waveform Inversion ◽  
Large Area ◽  
Wave Inversion ◽  
Full Waveform

Quantitative guided wave thickness mapping in plate-like structures and pipelines is of significant importance for the petrochemical industry to accurately estimate the minimum remaining wall thickness in the presence of corrosion, as guided waves can inspect a large area without needing direct access. Although a number of inverse algorithms have been studied and implemented in guided wave reconstruction, a primary assumption is widely used: the three-dimensional guided wave inversion of thickness is simplified as a two-dimensional acoustic wave inversion of velocity, with the dispersive nature of the waves linking thickness to velocity. This assumption considerably simplifies the inversion procedure; however, it makes it impossible to account for mode conversion. In reality, mode conversion is quite common in guided wave scattering with asymmetric wall loss, and compared with non-converted guided wave modes, converted modes may provide greater access to valuable information about the thickness variation, which, if exploited, could lead to improved performance. Geometrical full waveform inversion (GFWI) is an ideal tool for this, since it can account for mode conversion. In this paper, quantitative thickness reconstruction based on GFWI is developed in a plate cross-section and applied to study the performance of thickness reconstruction using mode conversion.

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.

NUMERICAL MODELING OF WALL THINNING DEFECTS CHARACTERIZATION: APPLICATIONS IN LAMB WAVE GENERATION AND INTERACTION

2008 ◽  
Vol 22 (11) ◽  
pp. 935-940
Author(s):  
HYUNJO JEONG ◽  
SEUNG-SEOK LEE ◽  
YOUNG-GIL KIM
Keyword(s):  
Guided Waves ◽  
Lamb Waves ◽  
Mode Conversion ◽  
Wave Interaction ◽  
Guided Wave ◽  
Destructive Interference ◽  
Wall Thinning ◽  
Mode Dispersion ◽  
Periodic Ring ◽  
Axisymmetric Scattering

The generation of axisymmetric Lamb waves and interaction with wall thinning (corrosion) defects in hollow cylinders are simulated using the finite element method. Guided wave interaction with defects in cylinders is challenged by the multi-mode dispersion and the mode conversion. In this paper, two longitudinal, axisymmetric modes are generated using the concept of a time-delay periodic ring arrays (TDPRA), which makes use of the constructive/destructive interference concept to achieve the unidirectional emission and reception of guided waves. The axisymmetric scattering by the wall thinning extending in full circumference of a cylinder is studied with a two-dimensional FE simulation. The effect of wall thinning depth, axial extension, and the edge shape on the reflections of guided waves is discussed.

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.

Detection and sizing of disbond in multilayer bonded structure using modally selective guided wave

2019 ◽  
pp. 147592171986627 ◽  
Author(s):  
Kai Wang ◽  
Menglong Liu ◽  
Wuxiong Cao ◽  
Weidong Yang ◽  
Zhongqing Su ◽  
...  
Keyword(s):  
Guided Waves ◽  
Mode Conversion ◽  
Interfacial Strength ◽  
Surface Preparation ◽  
Poor Quality ◽  
Guided Wave ◽  
External Loading ◽  
Ultrasonic Guided Wave ◽  
Disbond Detection ◽  
Effective Wave

Bonded structures are frequently adopted in structural connections and are highly prone to degradation or decrease of interfacial strength due to adhesive aging, poor quality of surface preparation, as well as the exposure to harsh environment and external loading. This study addresses the establishment of a framework in which a modally selective ultrasonic guided wave is used for disbond identification and sizing. In this framework, the propagating and evanescent modes of ultrasonic guided waves are first obtained, followed by the excitability analysis for each ultrasonic guided wave propagating mode, providing a theoretical basis for effective wave excitation in the experiment. Then the interaction of ultrasonic guided wave with disbond is interrogated analytically using a method combining semi-analytical finite element and normal mode expansion, whereby wave transmission, wave reflection, and mode conversion can be calculated quantitatively. Taking all these aspects into account, mode 11 at around 3.85 MHz features a high propagation velocity, large mode excitability, and increasing amplitude drop with the enlargement of disbond size, and is thus selected for disbond detection. Both numerical and experimental validations are performed, in which disbonds of different lengths from 10 to 40 mm are examined, and the results well corroborate the effectiveness of the proposed framework for ultrasonic guided wave–based disbond detection.

EMAT-Based Inspection of Concrete-Filled Steel Pipes for Internal Voids and Inclusions

2002 ◽  
Vol 124 (3) ◽  
pp. 265-272 ◽  
Author(s):  
Won-Bae Na ◽  
Tribikram Kundu
Keyword(s):  
Guided Waves ◽  
Acoustic Method ◽  
Guided Wave ◽  
Long Distance ◽  
Steel Pipes ◽  
Acoustic Transducers ◽  
Bending Resistance ◽  
Good Potential ◽  
Internal Volume ◽  
Electro Magnetic

Concrete-filled steel pipes have been used as piles for supporting civil and marine structures. These piles provide good bending resistance, and can be easily spliced for long depth installation. However, these piles are usually exposed in hostile environments such as seawater and deicing materials. Thus, the outside corrosion of the steel pipe can reduce the wall thickness and the corrosion-induced delamination of internal concrete can increase internal volume or pressure. In addition, the void that can possibly exist in the pipe reduces the bending resistance. To avoid structural failure due to this type of deterioration, appropriate inspection and repair techniques are to be developed. The acoustic method is attractive for this inspection since it is relatively simple and versatile. Especially, guided wave techniques have strong potentials for this inspection because of long-distance inspection capability. There are different transducer-coupling mechanisms available for the guided wave inspection techniques. Electro-magnetic acoustic transducers (EMATs) give relatively consistent results in comparison to piezoelectric transducers since they do not need any couplant. EMATs are used for transmitting and receiving cylindrical guided waves through concrete-filled steel pipes. It is shown that EMAT-generated cylindrical guided wave techniques have good potential for the interface inspection of concrete-filled steel pipes.

Efficient Modeling of Nonlinear Scattering of Ultrasonic Guided Waves From Fatigue Cracks Using Local Interaction Simulation Approach

2016 ◽  
Author(s):  
Yanfeng Shen ◽  
Carlos E. S. Cesnik
Keyword(s):  
Fatigue Crack ◽  
Guided Waves ◽  
Mode Conversion ◽  
Fatigue Cracks ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Nonlinear Scattering ◽  
Absorbing Boundary ◽  
Interaction Simulation ◽  
Interior Damage

This paper presents an efficient modeling technique to study the nonlinear scattering of ultrasonic guided waves from fatigue damage. A Local Interaction Simulation Approach (LISA) is adopted, which possesses the versatility to capture arbitrary fatigue crack shapes. The stick-slip contact dynamics is implemented in the LISA model via the penalty method, which captures the nonlinear interactions between guided waves and fatigue cracks. The LISA framework achieves remarkable computation efficiency with its parallel implementation using Compute Unified Device Architecture (CUDA) executed on GPUs. A small-size LISA model is tailored for the purpose of extracting the guided wave scattering features. The model consists of an interior damage region and an exterior absorbing boundary. The interior damage region captures various types of fatigue crack scenarios, while the exterior absorbing boundary surrounds the damage model to eliminate boundary reflections. Thus, the simulation of guided wave scattering in an infinite media can be achieved utilizing a small-size local LISA model. Due to the parallel CUDA implementation and the small-size nature, this local LISA model is highly efficient. Selective mode generation is achieved by coupling/decoupling excitation profiles with certain wave mode shapes, which allows the study of sensitivity of different wave modes to a certain fatigue damage situation. At the sensing locations, mode decomposition is performed on the scattering waves, which enables the study of mode conversion at the damage. Fourier analysis allows the extraction of scattering features at both fundamental and higher harmonic frequencies. A numerical case study on nonlinear scattering of guided waves from a fatigue crack is given. The higher harmonic generation and mode conversion phenomena are presented using the wave damage interaction coefficients (WDIC), from which the sensitive detection directions can be inferred to place sensors. This study can provide guidelines for the effective design of sensitive SHM systems using nonlinear ultrasonic guided waves for fatigue crack detection.

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