Pub Date : 2020-04-06DOI: 10.1080/09349847.2020.1745341
Jones Owusu Twumasi, P. Destefano, J. Christian
ABSTRACT This paper proposes a probabilistic framework for assessing the condition of structural concrete with respect to moisture contained within cured concrete using a 10 GHz synthetic aperture radar (SAR) imaging system. Functional relationships between integrated SAR amplitude (SAR image index) and moisture content have been developed in previous studies utilizing experimental data collected in a controlled laboratory environment. These studies have shown that the integrated SAR amplitude (SAR image index) increases exponentially with an increase in moisture content at a given water-to-cement (w/c) ratio. In this study, a reliability model is developed using the integrated SAR amplitude and moisture content relationships from an experimental study which included concrete specimens with five different w/c ratios in addition to variations of critical functional parameters and Monte Carlo simulation techniques. The reliability model of moisture content detected with synthetic aperture radar in this study follows a normal distribution. An illustrative example is presented to demonstrate the reliability-based methods of measuring in-place moisture content using an integrated SAR amplitude. The findings from this study emphasize the need to consider the variation of parameters affecting nondestructive SAR imaging results for the purposes of diagnosing moisture content of aged structural concrete.
{"title":"A Reliability-Based Condition Assessment of Structural Concrete Using Synthetic Aperture Radar Imaging Techniques","authors":"Jones Owusu Twumasi, P. Destefano, J. Christian","doi":"10.1080/09349847.2020.1745341","DOIUrl":"https://doi.org/10.1080/09349847.2020.1745341","url":null,"abstract":"ABSTRACT This paper proposes a probabilistic framework for assessing the condition of structural concrete with respect to moisture contained within cured concrete using a 10 GHz synthetic aperture radar (SAR) imaging system. Functional relationships between integrated SAR amplitude (SAR image index) and moisture content have been developed in previous studies utilizing experimental data collected in a controlled laboratory environment. These studies have shown that the integrated SAR amplitude (SAR image index) increases exponentially with an increase in moisture content at a given water-to-cement (w/c) ratio. In this study, a reliability model is developed using the integrated SAR amplitude and moisture content relationships from an experimental study which included concrete specimens with five different w/c ratios in addition to variations of critical functional parameters and Monte Carlo simulation techniques. The reliability model of moisture content detected with synthetic aperture radar in this study follows a normal distribution. An illustrative example is presented to demonstrate the reliability-based methods of measuring in-place moisture content using an integrated SAR amplitude. The findings from this study emphasize the need to consider the variation of parameters affecting nondestructive SAR imaging results for the purposes of diagnosing moisture content of aged structural concrete.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"54 1","pages":"216 - 235"},"PeriodicalIF":1.4,"publicationDate":"2020-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82313399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-06DOI: 10.1080/09349847.2020.1745340
Meng Qifeng, S. Kai, Z. Li-pan, Ning Ning, Huang Huabin
ABSTRACT This study proposed a new magnetic induction tomography (MIT) sensor-based electromagnetic induction to reconstruct the conductivity distribution of target conductors and ultimately visualize carbon fiber reinforced plastic (CFRP) plates to measure their defects. This unique MIT sensor was designed for all coil centers located in one line, whereas perpendicular center lines of excitation and detection coils were simulated in a 3D finite element model. The parameters of frequencies, turns, excitation currents, and liftoffs were optimized to further improve sensitivity. Four broken wire defects at different depths were also inspected in an experiment and imaged by the Landweber algorithm. The new probe effectively identified the 4 mm × 4 mm × 0.5 mm defect buried at 1.5 mm. The different depths of defects were also established by the voltage amplitude of the detection coil. The concavity of the reconstructed images effectively represented the depths of the defects. Hence, this MIT probe is highly useful in quantitatively measuring the defects of CFRP plates and visually displaying.
{"title":"Study of Defects in Carbon Fiber Reinforced Composites Visualized by Magnetic Induction Tomography","authors":"Meng Qifeng, S. Kai, Z. Li-pan, Ning Ning, Huang Huabin","doi":"10.1080/09349847.2020.1745340","DOIUrl":"https://doi.org/10.1080/09349847.2020.1745340","url":null,"abstract":"ABSTRACT This study proposed a new magnetic induction tomography (MIT) sensor-based electromagnetic induction to reconstruct the conductivity distribution of target conductors and ultimately visualize carbon fiber reinforced plastic (CFRP) plates to measure their defects. This unique MIT sensor was designed for all coil centers located in one line, whereas perpendicular center lines of excitation and detection coils were simulated in a 3D finite element model. The parameters of frequencies, turns, excitation currents, and liftoffs were optimized to further improve sensitivity. Four broken wire defects at different depths were also inspected in an experiment and imaged by the Landweber algorithm. The new probe effectively identified the 4 mm × 4 mm × 0.5 mm defect buried at 1.5 mm. The different depths of defects were also established by the voltage amplitude of the detection coil. The concavity of the reconstructed images effectively represented the depths of the defects. Hence, this MIT probe is highly useful in quantitatively measuring the defects of CFRP plates and visually displaying.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"26 1","pages":"203 - 215"},"PeriodicalIF":1.4,"publicationDate":"2020-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80418533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-03DOI: 10.1080/09349847.2019.1623958
J. Prawin, A. Rao
ABSTRACT Most of the practical engineering structures exhibit nonlinearity due to nonlinear dynamic characteristics of structural joints, nonlinear boundary conditions, and nonlinear material properties. In this paper, we investigate the effectiveness of five selected frequency domain techniques for the detection of nonlinear behaviour of the structure. Numerical simulation studies have been carried out by choosing a typical benchmark problem i.e., spring-mass system. The strength and weaknesses of each of the technique are evaluated with respect to their sensitivity to measurement noise. Efforts are also made in this paper to estimate the degree of nonlinearity present in the system using all the five techniques. Numerical investigations are later complemented with experimental studies to demonstrate their practical applicability. The investigations carried out in this paper clearly highlight the effectiveness of the bispectrum technique in robustly identifying the presence and also the degree of nonlinearity in the system.
{"title":"Detection and Quantification of Non-Linear Structural Behavior Using Frequency Domain Methods","authors":"J. Prawin, A. Rao","doi":"10.1080/09349847.2019.1623958","DOIUrl":"https://doi.org/10.1080/09349847.2019.1623958","url":null,"abstract":"ABSTRACT Most of the practical engineering structures exhibit nonlinearity due to nonlinear dynamic characteristics of structural joints, nonlinear boundary conditions, and nonlinear material properties. In this paper, we investigate the effectiveness of five selected frequency domain techniques for the detection of nonlinear behaviour of the structure. Numerical simulation studies have been carried out by choosing a typical benchmark problem i.e., spring-mass system. The strength and weaknesses of each of the technique are evaluated with respect to their sensitivity to measurement noise. Efforts are also made in this paper to estimate the degree of nonlinearity present in the system using all the five techniques. Numerical investigations are later complemented with experimental studies to demonstrate their practical applicability. The investigations carried out in this paper clearly highlight the effectiveness of the bispectrum technique in robustly identifying the presence and also the degree of nonlinearity in the system.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"114 1","pages":"69 - 106"},"PeriodicalIF":1.4,"publicationDate":"2020-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87967469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-03DOI: 10.1080/09349847.2019.1634226
E. Yahaghi, A. Movafeghi, B. Rokrok, M. Mirzapour
ABSTRACT The life of an aircraft depends on the early detection and removal of corrosion in its structure. The importance of detecting corrosion cannot be understated, because corrosion can cause other kinds of damage, such as cracks. Radiography is an important method for the detection of hidden defects in aircraft structure. To maximize information extraction from the radiographic images, the noise of the system should be minimized, or the contrast of the defective region should be maximized by different methods. The development of effective image processing methods, within both the spatial and frequency domains, is important to the research of industrial radiographic testing. In this study, the geometric locally adaptive sharpening method was used to improve hidden structure visualization of details and defects from aircraft part radiographs. The method relies on sharpening by using the steering kernel regression method. Here, the enhancing contrast and sharpening algorithm are effectively mixed together. The proposed algorithm was successfully applied to radiographic images of aircraft parts. An improvement of the structure detail visualization and defect region detection was achieved by sharpening the edges and preserving fine detail imaging information. Experts’ reviews showed that defect regions from the geometric locally adaptive sharpening reconstructed images were better visualized than the original images. Also, the resulting evaluation of the output images shows that the edges are sharpened by the proposed method and that the background of the image decreases to zero.
{"title":"Defects Detection of Digital Radiographic Images of Aircraft Structure Materials via Geometric Locally Adaptive Sharpening","authors":"E. Yahaghi, A. Movafeghi, B. Rokrok, M. Mirzapour","doi":"10.1080/09349847.2019.1634226","DOIUrl":"https://doi.org/10.1080/09349847.2019.1634226","url":null,"abstract":"ABSTRACT The life of an aircraft depends on the early detection and removal of corrosion in its structure. The importance of detecting corrosion cannot be understated, because corrosion can cause other kinds of damage, such as cracks. Radiography is an important method for the detection of hidden defects in aircraft structure. To maximize information extraction from the radiographic images, the noise of the system should be minimized, or the contrast of the defective region should be maximized by different methods. The development of effective image processing methods, within both the spatial and frequency domains, is important to the research of industrial radiographic testing. In this study, the geometric locally adaptive sharpening method was used to improve hidden structure visualization of details and defects from aircraft part radiographs. The method relies on sharpening by using the steering kernel regression method. Here, the enhancing contrast and sharpening algorithm are effectively mixed together. The proposed algorithm was successfully applied to radiographic images of aircraft parts. An improvement of the structure detail visualization and defect region detection was achieved by sharpening the edges and preserving fine detail imaging information. Experts’ reviews showed that defect regions from the geometric locally adaptive sharpening reconstructed images were better visualized than the original images. Also, the resulting evaluation of the output images shows that the edges are sharpened by the proposed method and that the background of the image decreases to zero.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"45 1","pages":"107 - 115"},"PeriodicalIF":1.4,"publicationDate":"2020-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77508383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-03-03DOI: 10.1080/09349847.2019.1645253
Seyed Fouad Karimian, T. Chu
ABSTRACT Digital Image Correlation (DIC) is a known Non-Destructive Evaluation (NDE) method used in various industries. DIC requires a randomly produced pattern, known as speckle pattern, to track and generate strain maps. The speckle patterns are fundamental for DIC applications. DIC uses images of these speckle patterns before and after a load has been applied to generate strain maps by comparing the changes between speckle pattern images. In this study, a speckle pattern is sought to implement within adhesive joints. The speckle pattern must be trackable using ultrasonic imaging; therefore, it is chosen from materials with high acoustic impedance metals. By tracking the speckle pattern and using DIC, defects within joints will be revealed. This allows non-destructive analysis to be conducted on adhesive joints to detect defects which may go undetected using conventional ultrasonic techniques.
{"title":"Developing a Speckle Pattern to Evaluate Adhesive Joints Using Digital Image Correlation","authors":"Seyed Fouad Karimian, T. Chu","doi":"10.1080/09349847.2019.1645253","DOIUrl":"https://doi.org/10.1080/09349847.2019.1645253","url":null,"abstract":"ABSTRACT Digital Image Correlation (DIC) is a known Non-Destructive Evaluation (NDE) method used in various industries. DIC requires a randomly produced pattern, known as speckle pattern, to track and generate strain maps. The speckle patterns are fundamental for DIC applications. DIC uses images of these speckle patterns before and after a load has been applied to generate strain maps by comparing the changes between speckle pattern images. In this study, a speckle pattern is sought to implement within adhesive joints. The speckle pattern must be trackable using ultrasonic imaging; therefore, it is chosen from materials with high acoustic impedance metals. By tracking the speckle pattern and using DIC, defects within joints will be revealed. This allows non-destructive analysis to be conducted on adhesive joints to detect defects which may go undetected using conventional ultrasonic techniques.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"28 1","pages":"116 - 132"},"PeriodicalIF":1.4,"publicationDate":"2020-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90105720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/09349847.2019.1617914
S. Su, Xiaoping Ma, Wei Wang, Yiyi Yang
ABSTRACT Magnetic memory method (MMM) is widely used for diagnosing ferromagnetic material on early stage as a nondestructive technology, but no clear description exists for the influence of stress on MMM signals at the micro-defect position on the surface of steel wire yet. Hence, based on traditional magnetic charge model, a stress-dependent magnetic charge model that combined the Jiles magneto-mechanical constitutive relation was intended to calculate the MMM signals around micro-defect on surface of steel wire. Meanwhile, the Hp(y) signals on surface of steel wire with different defects were measured during the whole tension test. By comparing the results of theoretical model and experiment, some conclusions can be drawn. First, the position of vale-peak on Hp(y) signals curves can be used to determine the micro-defect on steel wire. Secondly, the vale-peak amplitude (Sv-p) and vale-peak width (Lv-p) of Hp(y) signals curves, as two characteristic parameters of magnetic signals, not only can reflect the variations of defect depth and defect width, but also judge the load subjected by specimen. Sv-p has an approximate growth with the increase of defect depth as a whole, but decreases with the increase of loads. And the effect of load on Sv-p increases with defect depth. Lv-p has an approximate growth with the increase of defect width as a whole, but does not change with the increase of loads. Finally, the stress-dependent magnetic charge model can be better to reflect the changing laws of Hp(y) signals around defect and can be used for the numerical analysis of MMM signals on surface of steel wire.
{"title":"Stress-Dependent Magnetic Charge Model for Micro-Defects of Steel Wire Based on the Magnetic Memory Method","authors":"S. Su, Xiaoping Ma, Wei Wang, Yiyi Yang","doi":"10.1080/09349847.2019.1617914","DOIUrl":"https://doi.org/10.1080/09349847.2019.1617914","url":null,"abstract":"ABSTRACT Magnetic memory method (MMM) is widely used for diagnosing ferromagnetic material on early stage as a nondestructive technology, but no clear description exists for the influence of stress on MMM signals at the micro-defect position on the surface of steel wire yet. Hence, based on traditional magnetic charge model, a stress-dependent magnetic charge model that combined the Jiles magneto-mechanical constitutive relation was intended to calculate the MMM signals around micro-defect on surface of steel wire. Meanwhile, the Hp(y) signals on surface of steel wire with different defects were measured during the whole tension test. By comparing the results of theoretical model and experiment, some conclusions can be drawn. First, the position of vale-peak on Hp(y) signals curves can be used to determine the micro-defect on steel wire. Secondly, the vale-peak amplitude (Sv-p) and vale-peak width (Lv-p) of Hp(y) signals curves, as two characteristic parameters of magnetic signals, not only can reflect the variations of defect depth and defect width, but also judge the load subjected by specimen. Sv-p has an approximate growth with the increase of defect depth as a whole, but decreases with the increase of loads. And the effect of load on Sv-p increases with defect depth. Lv-p has an approximate growth with the increase of defect width as a whole, but does not change with the increase of loads. Finally, the stress-dependent magnetic charge model can be better to reflect the changing laws of Hp(y) signals around defect and can be used for the numerical analysis of MMM signals on surface of steel wire.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"78 1","pages":"24 - 47"},"PeriodicalIF":1.4,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76778301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/09349847.2019.1709677
Mohsen Mohsenzadeh, S. R. Hamzeloo, M. Barzegar, A. Pourkamali Anaraki
ABSTRACT The electro-mechanical impedance (EMI) method has been accepted as an effective technique for detecting damages in the Structural health monitoring (SHM). EMI at any point of the structure depends on material properties, geometry and boundary conditions that all appears in dynamic stiffness of the structure. In spite of the expensive experimental methods for measuring the mechanical impedance, or the cheaper one electromechanical impedance, of structures, various analytical methods could be substitutions for them. In this paper, an analytical method is developed to obtain the EMI response of L-shaped beams through calculating the dynamic stiffness of the structure. To verify the model, an experimental setup with an embedded piezoelectric wafer active sensor (PWAS) is carried out. The results have shown that EMI and its real part, extracted by the current analytical method, are with good agreement of the experimental results. Also, the dynamic stiffness of the structure directly depends on the mode shapes of the structure and its natural frequencies in terms of the excitation frequency. The peaks of the real part of the EMI results related to the coincidence between agitation frequency value and natural frequencies of the structure.
{"title":"Analytical Model of the Electro-Mechanical Impedance Response of Frame Structures with L-Shaped Beams","authors":"Mohsen Mohsenzadeh, S. R. Hamzeloo, M. Barzegar, A. Pourkamali Anaraki","doi":"10.1080/09349847.2019.1709677","DOIUrl":"https://doi.org/10.1080/09349847.2019.1709677","url":null,"abstract":"ABSTRACT The electro-mechanical impedance (EMI) method has been accepted as an effective technique for detecting damages in the Structural health monitoring (SHM). EMI at any point of the structure depends on material properties, geometry and boundary conditions that all appears in dynamic stiffness of the structure. In spite of the expensive experimental methods for measuring the mechanical impedance, or the cheaper one electromechanical impedance, of structures, various analytical methods could be substitutions for them. In this paper, an analytical method is developed to obtain the EMI response of L-shaped beams through calculating the dynamic stiffness of the structure. To verify the model, an experimental setup with an embedded piezoelectric wafer active sensor (PWAS) is carried out. The results have shown that EMI and its real part, extracted by the current analytical method, are with good agreement of the experimental results. Also, the dynamic stiffness of the structure directly depends on the mode shapes of the structure and its natural frequencies in terms of the excitation frequency. The peaks of the real part of the EMI results related to the coincidence between agitation frequency value and natural frequencies of the structure.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"17 1","pages":"187 - 202"},"PeriodicalIF":1.4,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87852011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/09349847.2019.1617913
E. Dris, R. Drai, M. Bentahar, D. Berkani
ABSTRACT This paper presents a probabilistic approach to continuously track the sequential movement of the multiple impacts considered as acoustic emission (AE) sources. Continuous wavelet transform (CWT) analysis is used to determine the time of arrival (TOA) of the different AE hits by taking into account systematic errors due to the Heisenberg uncertainty. Then, the Extended Kalman Filter (EKF) is applied to simultaneously estimate the locations of impact points and the group velocity of the involved Lamb waves at a specific frequency. To validate the performance of the proposed probabilistic approach, including uncertainties from modeling error and measurement noise, experiments on a copper panel are performed using AE hits generated by Pencil-Lead Breaks (PLBs). Measurements help appreciate robustness of the proposed approach with consequent potential applications in structural health monitoring of industrial parts and structures.
{"title":"Adaptive Algorithm for Estimating and Tracking the Location of Multiple Impacts on a Plate-Like Structure","authors":"E. Dris, R. Drai, M. Bentahar, D. Berkani","doi":"10.1080/09349847.2019.1617913","DOIUrl":"https://doi.org/10.1080/09349847.2019.1617913","url":null,"abstract":"ABSTRACT This paper presents a probabilistic approach to continuously track the sequential movement of the multiple impacts considered as acoustic emission (AE) sources. Continuous wavelet transform (CWT) analysis is used to determine the time of arrival (TOA) of the different AE hits by taking into account systematic errors due to the Heisenberg uncertainty. Then, the Extended Kalman Filter (EKF) is applied to simultaneously estimate the locations of impact points and the group velocity of the involved Lamb waves at a specific frequency. To validate the performance of the proposed probabilistic approach, including uncertainties from modeling error and measurement noise, experiments on a copper panel are performed using AE hits generated by Pencil-Lead Breaks (PLBs). Measurements help appreciate robustness of the proposed approach with consequent potential applications in structural health monitoring of industrial parts and structures.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"33 1","pages":"1 - 23"},"PeriodicalIF":1.4,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81054026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-01-02DOI: 10.1080/09349847.2019.1595987
Guanyu Piao, Jingbo Guo, Tiehua Hu, H. Leung
ABSTRACT The magnetic flux leakage (MFL) inspection technology is widely used in pipeline industry to detect defects to ensure pipeline safety. During the high-speed inspection, a relative motion occurred between the pipeline inspection gauge (PIG) and the steel pipe wall will generate motion-induced eddy current (MIEC). There is a lack of research on analyzing the effect of MIEC on high-speed MFL inspection for thick-wall steel pipe. In this article, a three-dimensional (3D) finite-element method (FEM) simulations are conducted with an inspection speed range of 0 m/s to 8 m/s and a wall thickness range of 8 mm to 15 mm. Simulation results show that both high-speed inspection and thick-wall thickness will decrease the magnetization of steel pipe. It is observed that, at the speed of 8 m/s and the thickness of 15 mm, the magnetic field strength is lower than 2 kA/m and the steel pipe exits from the magnetic saturation zone, which causes the severe distortion of three-axis MFL signals, and the signal-to-noise ratio (SNR) is lower than 6 dB. A high-speed PIG is developed here for experiments to measure the three-axis MFL signals. The characteristics of simulated and measured MFL signals are found to be quite consistent.
{"title":"The Effect of Motion-Induced Eddy Current on High-Speed Magnetic Flux Leakage (MFL) Inspection for Thick-Wall Steel Pipe","authors":"Guanyu Piao, Jingbo Guo, Tiehua Hu, H. Leung","doi":"10.1080/09349847.2019.1595987","DOIUrl":"https://doi.org/10.1080/09349847.2019.1595987","url":null,"abstract":"ABSTRACT The magnetic flux leakage (MFL) inspection technology is widely used in pipeline industry to detect defects to ensure pipeline safety. During the high-speed inspection, a relative motion occurred between the pipeline inspection gauge (PIG) and the steel pipe wall will generate motion-induced eddy current (MIEC). There is a lack of research on analyzing the effect of MIEC on high-speed MFL inspection for thick-wall steel pipe. In this article, a three-dimensional (3D) finite-element method (FEM) simulations are conducted with an inspection speed range of 0 m/s to 8 m/s and a wall thickness range of 8 mm to 15 mm. Simulation results show that both high-speed inspection and thick-wall thickness will decrease the magnetization of steel pipe. It is observed that, at the speed of 8 m/s and the thickness of 15 mm, the magnetic field strength is lower than 2 kA/m and the steel pipe exits from the magnetic saturation zone, which causes the severe distortion of three-axis MFL signals, and the signal-to-noise ratio (SNR) is lower than 6 dB. A high-speed PIG is developed here for experiments to measure the three-axis MFL signals. The characteristics of simulated and measured MFL signals are found to be quite consistent.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"25 1","pages":"48 - 67"},"PeriodicalIF":1.4,"publicationDate":"2020-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81000869","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-01DOI: 10.1080/09349847.2018.1459988
Bo Feng, Yihua Kang, Yanhua Sun, Zhiyang Deng
ABSTRACT In high-speed magnetic flux leakage (MFL) testing, the tested workpieces pass rapidly through magnetizers. Thus, the magnetization time for workpieces is short. Because of the eddy current effect, the magnetic field inside the workpieces cannot instantly reach equilibrium, and if the magnetizing time is insufficient for the field to reach equilibrium, the MFL signals will be changed because of incomplete magnetization. In this article, the magnetization time lag caused by eddy currents and the influence of this lag on high-speed MFL testing is investigated. The time required for magnetic field to reach equilibrium in specimens, including steel bars and pipes, is obtained by theoretical calculations, finite element simulations, and experiments. The results indicate that the time required for a magnetic field inside a specimen to reach equilibrium is in the range of 50–100 ms. Using conventional magnetizers, the defect signals at testing speed of 10 m/s change because the workpiece reaches the detection zone before the magnetic field inside reaches the stable state. A simple solution is to increase the axial length of the magnetizing coil. After this procedure, signals obtained at 0.1 m/s and 10 m/s are almost identical.
{"title":"Magnetization Time Lag Caused by Eddy Currents and Its Influence on High-Speed Magnetic Flux Leakage Testing","authors":"Bo Feng, Yihua Kang, Yanhua Sun, Zhiyang Deng","doi":"10.1080/09349847.2018.1459988","DOIUrl":"https://doi.org/10.1080/09349847.2018.1459988","url":null,"abstract":"ABSTRACT In high-speed magnetic flux leakage (MFL) testing, the tested workpieces pass rapidly through magnetizers. Thus, the magnetization time for workpieces is short. Because of the eddy current effect, the magnetic field inside the workpieces cannot instantly reach equilibrium, and if the magnetizing time is insufficient for the field to reach equilibrium, the MFL signals will be changed because of incomplete magnetization. In this article, the magnetization time lag caused by eddy currents and the influence of this lag on high-speed MFL testing is investigated. The time required for magnetic field to reach equilibrium in specimens, including steel bars and pipes, is obtained by theoretical calculations, finite element simulations, and experiments. The results indicate that the time required for a magnetic field inside a specimen to reach equilibrium is in the range of 50–100 ms. Using conventional magnetizers, the defect signals at testing speed of 10 m/s change because the workpiece reaches the detection zone before the magnetic field inside reaches the stable state. A simple solution is to increase the axial length of the magnetizing coil. After this procedure, signals obtained at 0.1 m/s and 10 m/s are almost identical.","PeriodicalId":54493,"journal":{"name":"Research in Nondestructive Evaluation","volume":"6 1","pages":"189 - 204"},"PeriodicalIF":1.4,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89240216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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