Energy efficiency is the primary objective in optimal design of inductive power components. This goal is totally aligned with the minimization of power losses in the coils. Typically, coils have been constructed by wire winding but, more recently, the utilization of printed circuit board (PCB) constructions has become more common due to their advantages, i. e. low profile and ease of fabrication, among others. At the operating frequencies of magnetic power devices, multi-conductor cabling with litz structure is required to reduce losses. PCB loss optimization procedure involves determining the number and size of the tracks. Numerical simulation is a very powerful tool to obtain the parameters of magnetic devices. However, including the internal structure of multi-track wiring in the numerical simulation implies a very high computational cost and a low accuracy of the results, because the size of the tracks is very small. Techniques of homogenization of the cabling are used to overcome such difficulty, disregarding the internal structure in order to determine the fields in the system and their electrical equivalent by means of computational simulation. The coil losses are further determined on the basis of the characteristics of the cabling as well as of the surrounding fields. The preceding procedure has proven to be suitable for cables composed of strands of circular cross-section, but should be adjusted to apply to tracks of rectangular cross-section. In this paper, different homogenization techniques for PCB coils have been proposed and evaluated. A highly symmetric reference system is selected to reduce the computational cost of numerical modeling, but the conclusions can be applied to more complicated geometries without loss of generality. Finally, the results of the different homogenization techniques have been validated by comparison with experimental results.
{"title":"Performance evaluation of homogenization techniques for proximity losses in PCB coils applied to inductive devices","authors":"Alexis Narváez, Claudio Carretero, Jesús Acero","doi":"10.3233/jae-230184","DOIUrl":"https://doi.org/10.3233/jae-230184","url":null,"abstract":"Energy efficiency is the primary objective in optimal design of inductive power components. This goal is totally aligned with the minimization of power losses in the coils. Typically, coils have been constructed by wire winding but, more recently, the utilization of printed circuit board (PCB) constructions has become more common due to their advantages, i. e. low profile and ease of fabrication, among others. At the operating frequencies of magnetic power devices, multi-conductor cabling with litz structure is required to reduce losses. PCB loss optimization procedure involves determining the number and size of the tracks. Numerical simulation is a very powerful tool to obtain the parameters of magnetic devices. However, including the internal structure of multi-track wiring in the numerical simulation implies a very high computational cost and a low accuracy of the results, because the size of the tracks is very small. Techniques of homogenization of the cabling are used to overcome such difficulty, disregarding the internal structure in order to determine the fields in the system and their electrical equivalent by means of computational simulation. The coil losses are further determined on the basis of the characteristics of the cabling as well as of the surrounding fields. The preceding procedure has proven to be suitable for cables composed of strands of circular cross-section, but should be adjusted to apply to tracks of rectangular cross-section. In this paper, different homogenization techniques for PCB coils have been proposed and evaluated. A highly symmetric reference system is selected to reduce the computational cost of numerical modeling, but the conclusions can be applied to more complicated geometries without loss of generality. Finally, the results of the different homogenization techniques have been validated by comparison with experimental results.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140198671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a parametric study is carried out on carbon fiber-reinforced plastic (CFRP) materials to investigate how the spatially varying fiber distribution influences the measured signal in an eddy current testing (ECT) configuration. The measurement setup was modeled using finite element method, while the fiber distribution is taken into account by an inhomogeneous anisotropic conductivity tensor. The study revealed a trade-off relation between the size of the ECT coil and the maximal dynamic range of the ECT signal, which contributes to the understanding of the connection between the fiber arrangement and the ECT signal and provides an opportunity for optimal ECT coil design.
{"title":"Sensitivity analysis for the eddy current testing of carbon fiber reinforced plastic materials","authors":"Bálint Pintér, A. Bingler, S. Bilicz, J. Pávó","doi":"10.3233/jae-230142","DOIUrl":"https://doi.org/10.3233/jae-230142","url":null,"abstract":"In this work, a parametric study is carried out on carbon fiber-reinforced plastic (CFRP) materials to investigate how the spatially varying fiber distribution influences the measured signal in an eddy current testing (ECT) configuration. The measurement setup was modeled using finite element method, while the fiber distribution is taken into account by an inhomogeneous anisotropic conductivity tensor. The study revealed a trade-off relation between the size of the ECT coil and the maximal dynamic range of the ECT signal, which contributes to the understanding of the connection between the fiber arrangement and the ECT signal and provides an opportunity for optimal ECT coil design.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139604447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, a structurally simple transmissive all-dielectric metamaterial absorber is designed, fabricated and measured. The unit cell consists of photosensitive resin and water, which the water layers composed of rectangle loop, rectangular block and traffic circle. It achieves over 90% absorption of electromagnetic waves in the frequency range between 11.0 and 27.3 GHz. Meanwhile, three absorption peaks are located at 12.5, 18.4, and 26.0 GHz, which the absorptive are 97.4%, 98.3%, and 98.5%, respectively. In addition, the characteristics of the designed metamaterial reveal wide-incident angle absorption and polarization-insensitive properties. The experimental sample is measured by using the free-space method, and the experimental results are verified to be in well agreement with the simulation data. Observing the distribution of electric and magnetic fields at different resonance frequencies, the physical mechanism of the absorption is attributed to strong magnetic resonance. Therefore, the proposed metamaterial has potential for widespread use in the fields of civilian and military.
{"title":"Ultra-broadband transmission absorption of the all-dielectric water-based metamaterial","authors":"Zihan Chen, Zhaoyang Shen, Han Liu, Xiang Shu","doi":"10.3233/jae-230208","DOIUrl":"https://doi.org/10.3233/jae-230208","url":null,"abstract":"In this paper, a structurally simple transmissive all-dielectric metamaterial absorber is designed, fabricated and measured. The unit cell consists of photosensitive resin and water, which the water layers composed of rectangle loop, rectangular block and traffic circle. It achieves over 90% absorption of electromagnetic waves in the frequency range between 11.0 and 27.3 GHz. Meanwhile, three absorption peaks are located at 12.5, 18.4, and 26.0 GHz, which the absorptive are 97.4%, 98.3%, and 98.5%, respectively. In addition, the characteristics of the designed metamaterial reveal wide-incident angle absorption and polarization-insensitive properties. The experimental sample is measured by using the free-space method, and the experimental results are verified to be in well agreement with the simulation data. Observing the distribution of electric and magnetic fields at different resonance frequencies, the physical mechanism of the absorption is attributed to strong magnetic resonance. Therefore, the proposed metamaterial has potential for widespread use in the fields of civilian and military.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139607133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jie Deng, C. Pei, Yuange Zhang, Yinqiang Qu, Ke Deng, Hong-en Chen, Zhenmao Chen
It is necessary to detect subsurface defects for a key metallic structural component especially a multilayer coating to ensure its structural integrity. In this paper, an imaging algorithm using the synthetic aperture focusing technique (SAFT) is developed for processing surface wave signals of array pickup electromagnetic acoustic transducer (EMAT) to improve its signal-to-noise ratio and detectability of subsurface defects. In addition, an array pickup unit of surface wave EMAT with gap configuration is proposed to receive multi-channel surface wave signals and is optimized by adjusting its coil configuration such as number, spacing and detection distance in order to obtain better SAFT imaging result. Both simulation and measured EMAT surface wave signals are used for the defect imaging and all the results verified the validity and the efficiency of the proposed method.
{"title":"Imaging of subsurface defects with surface wave SAFT based on an array pickup EMAT","authors":"Jie Deng, C. Pei, Yuange Zhang, Yinqiang Qu, Ke Deng, Hong-en Chen, Zhenmao Chen","doi":"10.3233/jae-230148","DOIUrl":"https://doi.org/10.3233/jae-230148","url":null,"abstract":"It is necessary to detect subsurface defects for a key metallic structural component especially a multilayer coating to ensure its structural integrity. In this paper, an imaging algorithm using the synthetic aperture focusing technique (SAFT) is developed for processing surface wave signals of array pickup electromagnetic acoustic transducer (EMAT) to improve its signal-to-noise ratio and detectability of subsurface defects. In addition, an array pickup unit of surface wave EMAT with gap configuration is proposed to receive multi-channel surface wave signals and is optimized by adjusting its coil configuration such as number, spacing and detection distance in order to obtain better SAFT imaging result. Both simulation and measured EMAT surface wave signals are used for the defect imaging and all the results verified the validity and the efficiency of the proposed method.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139606380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conventional low-frequency electromagnetic wave (LFEM) transmitting antennas are enormous in size, which limits the application of LFEM in underground space. Rotating-magnet Based Mechanical Antennas can realize the miniaturization of low-frequency antennas, which is expected to bring new possibilities for underground electromagnetic detection or ground penetration communication. Firstly, this paper establishes a synthetic field method for solving the electromagnetic field of a rotating permanent magnet in the air-earth cross-domain case. The method equates the magnet as an orthogonal superposition of vertical and horizontal dipole sources, and the phase difference between vertical and horizontal dipole sources is 𝜋/2. Based on the half-space theory of multilayer planar media, the quasi-analytical solution of the electromagnetic field of the magnetic dipole in the case of air-earth trans dimensionality can be found by superposition. Secondly, based on the finite element numerical model, the trans-earth propagation characteristics of the electromagnetic field excited by the rotating permanent magnet across the air-earth dual domain are studied. At the same time, the radiation characteristics in the rotating plane of the permanent magnet are also studied. Again, this paper systematically investigates the influence of parameters such as earth conductivity, emission frequency, and propagation distance on the electromagnetic field propagation. Finally, the principle prototype is developed and experiments are carried out. The results show that the finite element numerical model established in this paper is correct, the experimental results are consistent with the theoretical values, and a field strength signal of 0.9 nT can be received at 20 m. The research work in this paper lays the foundation for the future use of mechanical antennas for electromagnetic detection and ground penetration communication.
传统的低频电磁波发射天线体积庞大，限制了低频电磁波在地下空间的应用。基于旋转磁体的机械天线可实现低频天线的小型化，有望为地下电磁探测或地面穿透通信带来新的可能。首先，本文建立了一种在空地跨域情况下求解旋转永磁体电磁场的合成场方法。该方法将磁体等效为垂直偶极源和水平偶极源的正交叠加，垂直偶极源和水平偶极源的相位差为𝜋/2。基于多层平面介质的半空间理论，可以通过叠加求得磁偶极在空地跨维情况下的电磁场准解析解。其次，基于有限元数值模型，研究了旋转永磁体激发的电磁场在空地双域中的跨地传播特性。同时，还研究了永磁体旋转平面内的辐射特性。再次，本文系统地研究了大地电导率、发射频率和传播距离等参数对电磁场传播的影响。最后，开发了原理样机并进行了实验。结果表明，本文建立的有限元数值模型是正确的，实验结果与理论值一致，在 20 米处可以接收到 0.9 nT 的场强信号。本文的研究工作为今后利用机械天线进行电磁探测和地面穿透通信奠定了基础。
{"title":"Research on electromagnetic field characteristics of rotating-magnet based mechanical antenna through the earth","authors":"Lipeng Wu, Wenwei Zhang, Xianjin Song, Guoqiang Liu, Jing Liu, Hui Xia, Liguo Fan","doi":"10.3233/jae-230080","DOIUrl":"https://doi.org/10.3233/jae-230080","url":null,"abstract":"Conventional low-frequency electromagnetic wave (LFEM) transmitting antennas are enormous in size, which limits the application of LFEM in underground space. Rotating-magnet Based Mechanical Antennas can realize the miniaturization of low-frequency antennas, which is expected to bring new possibilities for underground electromagnetic detection or ground penetration communication. Firstly, this paper establishes a synthetic field method for solving the electromagnetic field of a rotating permanent magnet in the air-earth cross-domain case. The method equates the magnet as an orthogonal superposition of vertical and horizontal dipole sources, and the phase difference between vertical and horizontal dipole sources is 𝜋/2. Based on the half-space theory of multilayer planar media, the quasi-analytical solution of the electromagnetic field of the magnetic dipole in the case of air-earth trans dimensionality can be found by superposition. Secondly, based on the finite element numerical model, the trans-earth propagation characteristics of the electromagnetic field excited by the rotating permanent magnet across the air-earth dual domain are studied. At the same time, the radiation characteristics in the rotating plane of the permanent magnet are also studied. Again, this paper systematically investigates the influence of parameters such as earth conductivity, emission frequency, and propagation distance on the electromagnetic field propagation. Finally, the principle prototype is developed and experiments are carried out. The results show that the finite element numerical model established in this paper is correct, the experimental results are consistent with the theoretical values, and a field strength signal of 0.9 nT can be received at 20 m. The research work in this paper lays the foundation for the future use of mechanical antennas for electromagnetic detection and ground penetration communication.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139527733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cai Long, Yuanyuan Wang, Haoran Dong, Yu Tao, Chaofeng Ye
It is still a challenging problem to detect small defects for eddy current array probes, which requires the probes to possess excellent sensitivity, as well as high spatial resolution. This paper presents a novel high-resolution magnetic field imaging probe with two rows of tunneling magnetoresistance (TMR) array sensors. The bare die sensors are integrated on a printed circuit board by golden wire bonding technology. The two rows of sensors are placed staggered with each other. The data of the two arrays are merged into a matrix, in which way the image pixel pitch is increased to 0.25 mm. The probe employs a differential scheme to suppress the noise, so as to detect the weak signal of small defects. To highlight the weak defect indications, feature extraction and segmentation algorithms are developed. The experimental results confirm that the proposed method can inspect a small defect with dimensions 1 mm (length) × 0.1 mm (width) × 0.1 mm (depth) on a stainless-steel sample.
{"title":"High resolution magnetic field imaging probe with two rows of TMR sensors for small defects inspection","authors":"Cai Long, Yuanyuan Wang, Haoran Dong, Yu Tao, Chaofeng Ye","doi":"10.3233/jae-230115","DOIUrl":"https://doi.org/10.3233/jae-230115","url":null,"abstract":"It is still a challenging problem to detect small defects for eddy current array probes, which requires the probes to possess excellent sensitivity, as well as high spatial resolution. This paper presents a novel high-resolution magnetic field imaging probe with two rows of tunneling magnetoresistance (TMR) array sensors. The bare die sensors are integrated on a printed circuit board by golden wire bonding technology. The two rows of sensors are placed staggered with each other. The data of the two arrays are merged into a matrix, in which way the image pixel pitch is increased to 0.25 mm. The probe employs a differential scheme to suppress the noise, so as to detect the weak signal of small defects. To highlight the weak defect indications, feature extraction and segmentation algorithms are developed. The experimental results confirm that the proposed method can inspect a small defect with dimensions 1 mm (length) × 0.1 mm (width) × 0.1 mm (depth) on a stainless-steel sample.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139624981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanping Shen, Ning Liu, Mingliang Sun, Biao-biao Wang, Yuxia Liang
Permanent magnet eddy current brake (PMECB) with high damping performance is widely used in engineering vibration suppression and braking. In this study, based on the braking dynamics of PMECB under impact load, the analysis method related to the damping characteristics are established, including a static magnetic model with flux leakage, a uniform damping force model with demagnetization effect and skin effect, and an acceleration damping force model with magnetic field distortion. The comparison of the analysis method, numerical simulation and experimental results verifies that the analysis method can reproduce the damping law under impact load. The results show that the maximum displacements of the analysis method and numerical simulation deviate from the experimental results within 3%. The analysis method can complete the calculation of the damping characteristics within a few seconds. The variations of the thickness, conductivity of the conductive cylinder, and air gap thickness have significant effects on the nonlinear and critical characteristics of the velocity-damping force curve, which can be corrected by changing the coefficients in the analysis method. In summary, the proposed analysis method can provide insights for rapid engineering design and optimization calculation of the PMECB by its completeness, accuracy, adaptability and rapidity.
{"title":"Analysis method of permanent magnet eddy current brake under impact load","authors":"Yanping Shen, Ning Liu, Mingliang Sun, Biao-biao Wang, Yuxia Liang","doi":"10.3233/jae-220194","DOIUrl":"https://doi.org/10.3233/jae-220194","url":null,"abstract":"Permanent magnet eddy current brake (PMECB) with high damping performance is widely used in engineering vibration suppression and braking. In this study, based on the braking dynamics of PMECB under impact load, the analysis method related to the damping characteristics are established, including a static magnetic model with flux leakage, a uniform damping force model with demagnetization effect and skin effect, and an acceleration damping force model with magnetic field distortion. The comparison of the analysis method, numerical simulation and experimental results verifies that the analysis method can reproduce the damping law under impact load. The results show that the maximum displacements of the analysis method and numerical simulation deviate from the experimental results within 3%. The analysis method can complete the calculation of the damping characteristics within a few seconds. The variations of the thickness, conductivity of the conductive cylinder, and air gap thickness have significant effects on the nonlinear and critical characteristics of the velocity-damping force curve, which can be corrected by changing the coefficients in the analysis method. In summary, the proposed analysis method can provide insights for rapid engineering design and optimization calculation of the PMECB by its completeness, accuracy, adaptability and rapidity.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139624419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vincenzo Mottola, A. Corbo Esposito, Gianpaolo Piscitelli, A. Tamburrino
In this paper we present a first non-iterative imaging method for nonlinear materials, based on Monotonicity Principle. Specifically, we deal with the inverse obstacle problem, where the aim is to retrieve a nonlinear anomaly embedded in linear known background. The Monotonicity Principle (MP) is a general property for various class of PDEs, that has recently generalized to nonlinear elliptic PDEs. Basically, it states a monotone relation between the point-wise value of the unknown material property and the boundary measurements. It is at the foundation of a class of non-iterative imaging methods, characterized by a very low execution time that makes them ideal candidates for real-time applications. In this work, we develop an inversion method that overcomes some of the peculiar difficulties in practical application of MP to imaging of nonlinear materials, preserving the feasibility for real-time applications. For the sake of clarity, we focus on a specific application, i.e. the Magnetostatic Permeability Tomography where the goal is retrieving the unknown (nonlinear) permeability by boundary measurements in DC operations. This choice is motivated by applications in the inspection of boxes and containers for security. Reconstructions from simulated data prove the effectiveness of the presented method.
{"title":"Tomography of nonlinear materials via the monotonicity principle","authors":"Vincenzo Mottola, A. Corbo Esposito, Gianpaolo Piscitelli, A. Tamburrino","doi":"10.3233/jae-230129","DOIUrl":"https://doi.org/10.3233/jae-230129","url":null,"abstract":"In this paper we present a first non-iterative imaging method for nonlinear materials, based on Monotonicity Principle. Specifically, we deal with the inverse obstacle problem, where the aim is to retrieve a nonlinear anomaly embedded in linear known background. The Monotonicity Principle (MP) is a general property for various class of PDEs, that has recently generalized to nonlinear elliptic PDEs. Basically, it states a monotone relation between the point-wise value of the unknown material property and the boundary measurements. It is at the foundation of a class of non-iterative imaging methods, characterized by a very low execution time that makes them ideal candidates for real-time applications. In this work, we develop an inversion method that overcomes some of the peculiar difficulties in practical application of MP to imaging of nonlinear materials, preserving the feasibility for real-time applications. For the sake of clarity, we focus on a specific application, i.e. the Magnetostatic Permeability Tomography where the goal is retrieving the unknown (nonlinear) permeability by boundary measurements in DC operations. This choice is motivated by applications in the inspection of boxes and containers for security. Reconstructions from simulated data prove the effectiveness of the presented method.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139532295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, we present a new non-iterative imaging method for Electrical Resistance Tomography (ERT). The problem in ERT is retrieving the spatial behaviour of the electrical conductivity by means of boundary measurements in steady-state conditions. Specifically, the interest is focused on the inverse obstacle problem, that consists in reconstructing the shape, position and dimension of one or more anomalies embedded in a known background. The proposed method, called Kernel Method, is based on the idea that if there exists a current density Jn that applied at the boundary ∂𝛺 of the domain under investigation 𝛺 produces the same scalar potential (on ∂𝛺), with and without anomalies, then the power density corresponding to Jn, evaluated on a configuration without anomalies, is vanishing in the region occupied by the latter. The proposed method has a very low computational cost. Indeed, the evaluation of the desired current density Jn on ∂𝛺 requires a negligible computational effort, and the reconstructions require only one forward problem.
{"title":"Imaging of conducting materials via the Kernel Method","authors":"A. Tamburrino, Vincenzo Mottola","doi":"10.3233/jae-230167","DOIUrl":"https://doi.org/10.3233/jae-230167","url":null,"abstract":"In this work, we present a new non-iterative imaging method for Electrical Resistance Tomography (ERT). The problem in ERT is retrieving the spatial behaviour of the electrical conductivity by means of boundary measurements in steady-state conditions. Specifically, the interest is focused on the inverse obstacle problem, that consists in reconstructing the shape, position and dimension of one or more anomalies embedded in a known background. The proposed method, called Kernel Method, is based on the idea that if there exists a current density Jn that applied at the boundary ∂𝛺 of the domain under investigation 𝛺 produces the same scalar potential (on ∂𝛺), with and without anomalies, then the power density corresponding to Jn, evaluated on a configuration without anomalies, is vanishing in the region occupied by the latter. The proposed method has a very low computational cost. Indeed, the evaluation of the desired current density Jn on ∂𝛺 requires a negligible computational effort, and the reconstructions require only one forward problem.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2024-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139534449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yuange Zhang, C. Pei, Jie Deng, Tianhao Liu, Hong-en Chen, Zhenmao Chen
Nondestructive testing (NDT) for damage in thermal barrier coatings (TBCs) is significant for the safety guarantee of gas turbine blades. As a new NDT technology, electromagnetic acoustic transducer (EMAT) is widely applied for NDT of conductive structural components due to its advantages of coupling-free and high adaptability. In this paper, numerical simulations are conducted to study the wave propagation and interaction with delamination defects in TBCs inspected with a Rayleigh wave EMAT of the Lorentz force mechanism. Based on the numerical results, the wave structure in TBC, wave conversion at delamination defect, time domain EMAT signals, and its B-scan images are evaluated and the feasibility of Rayleigh wave EMAT to inspect delamination in TBCs was theoretically clarified.
{"title":"Detection mechanism of delamination in thermal barrier coatings of turbine blade using a Rayleigh wave EMAT","authors":"Yuange Zhang, C. Pei, Jie Deng, Tianhao Liu, Hong-en Chen, Zhenmao Chen","doi":"10.3233/jae-230147","DOIUrl":"https://doi.org/10.3233/jae-230147","url":null,"abstract":"Nondestructive testing (NDT) for damage in thermal barrier coatings (TBCs) is significant for the safety guarantee of gas turbine blades. As a new NDT technology, electromagnetic acoustic transducer (EMAT) is widely applied for NDT of conductive structural components due to its advantages of coupling-free and high adaptability. In this paper, numerical simulations are conducted to study the wave propagation and interaction with delamination defects in TBCs inspected with a Rayleigh wave EMAT of the Lorentz force mechanism. Based on the numerical results, the wave structure in TBC, wave conversion at delamination defect, time domain EMAT signals, and its B-scan images are evaluated and the feasibility of Rayleigh wave EMAT to inspect delamination in TBCs was theoretically clarified.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138949894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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