International Journal of Applied Electromagnetics and Mechanics - Volume 74, issue 4

Authors: Stamou, Georgia | Angelopoulos, Spyridon | Hristoforou, Evangelos

Article Type: Research Article

Abstract: This paper presents a portable device based on an Anisotropic Magnetoresistance (AMR) sensor for Steel Health Monitoring. The system operates by detecting magnetic anomalies in ferromagnetic materials caused by strain, corrosion, etc. This sensor can have various applications in the transportation, building, and aerospace fields for safety and maintenance monitoring of ferromagnetic materials. In this work, a low-cost device, that combines a high-sensitivity AMR sensor, a microcontroller, and supporting electronics has been designed and implemented. This sensor allows the contactless measurement of the magnetic flux density along three axes, when placed above the material under test, while the microcontroller and …the required electronics enable real-time analysis and monitoring of measurements. In order to house and protect the sensor under various circumstances, a 3D-printed enclosure has also been created. This device can be used along with rehabilitation techniques for treatment of defective areas of an under-test material. Its versatility allows it to be employed in a variety of testing conditions for both single-point and scanning mode monitoring. The device’s portability, ease of use and applicability to on-site measurements make it accessible to a wide range of users, requiring only a personal computer to display the measurements. Finally, measurements are presented to prove the device’s accuracy for steel health monitoring. Show more

Keywords: Anisotropic Magnetoresistance (AMR), magnetic sensor, steel heath monitoring, microcontroller, magnetic anomaly detection

DOI: 10.3233/JAE-230137

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 357-362, 2024

Authors: A.R., Arjun | Sasi, B. | Kumar, Anish

Article Type: Research Article

Abstract: Eddy current measurements are prone to edge effects when measurements are carried out near a sample boundary. In order to reduce these edge effects, typically ferrite shields are used which constrain the magnetic field within the shield volume. However, their effects on sensitivity towards changes in conductivity for Sweep Frequency Eddy Current (SFEC) measurements have not been investigated. A 2D axisymmetric Finite Element Model (FEM) has been developed to predict the frequency response of impedance of SFEC probes. The model predicted that the addition of shields minimized edge effect but with reduced sensitivity. A simulation study is carried out to …optimize the probe design to increase the sensitivity of shielded ferrite probes. Based on these results, a probe is constructed with a custom ferrite shield and its shielding efficiency and probe sensitivity are compared experimentally with those for the probe with conventional ferrite shields. Show more

Keywords: Sweep Frequency Eddy Current Testing, Finite Element Model, edge effect, probe design optimization and sensitivity

DOI: 10.3233/JAE-230138

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 363-369, 2024

Authors: Brandão, Ana Carolina Pereira Soares | Fonseca, Ana Beatriz Dantas | Soares, Iane de Araujo | Pacheco, Clara Johanna | Fernandes, Daniel Mendes | Eckstein, Carlos Bruno | Nogueira Junior, Laudemiro | Almeida, Luiz Henrique de | Pereira, Gabriela Ribeiro

Article Type: Research Article

Abstract: HP austenitic stainless steel undergoes microstructural aging due to prolonged exposure to oxidizing and corrosive atmospheres in steam reforming furnaces. The derived aging states are classified by its service temperature and microstructural markers and monitoring it is important to residual life assessment. In this regard it was used a portable Eddy Current inspection system with the aid of machine learning classification tools, characterizing aging states in HP steel in real-time. The classification profile of a 12-meter tube was acquired, validated through Field Metallurgical Replication. The developed Eddy Current inspection system successfully differentiates three regions, revealing a progression of aging states.

Keywords: Reforming furnace, HP steel, eddy currents, machine learning, SVM

DOI: 10.3233/JAE-230139

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 371-377, 2024

Authors: Noël, Valentin | Rodet, Thomas | Lesselier, Dominique

Article Type: Research Article

Abstract: Non-destructive thermographic testing of damaged composite laminates modeled from the homogenization of fiber-reinforced polymers is a challenge, both because of its underlying complexity and because of the difficulties encountered in the quantification of uncertainties related to the identification and characterization of defects. To provide a rigorous framework that accepts data from different modalities and allows data fusion as well, a Bayesian neural network (BNN) [I. Kononenko, Biological Cybernetics 61 (5) (1989), 361–370] with two input streams is proposed, with a focus on local inter-layer delaminations identification and characterization.

Keywords: Non-destructive testing, fiber-reinforced laminates, infra-red thermal imaging, Bayesian neural network, uncertainty quantification

DOI: 10.3233/JAE-230140

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 379-386, 2024

Authors: Bouali, Ferroudja | Mohellebi, Hassane

Article Type: Research Article

Abstract: The present work concerns the study of the effect of variation of the thickness of 2D cylindrical test-piece and lift-off (the air gap between the sensor and the test-piece) on the sensor response in case of transient source current. The coupled circuit’s method employed is based on the mutual’s inductances calculation and with the association to Kirchhoff laws it yields to a transient algebraic equations system which is solved at each time step. The method is applied to the study of the pulsed eddy currents in cylindrical and axisymmetric device with electrical conductivity and geometrical dimensions variations.

Keywords: Coupled electric circuits, pulsed eddy current, non destructive testing and evaluation, geometry and physical properties, lift-off

DOI: 10.3233/JAE-230141

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 387-395, 2024

Authors: Pintér, Bálint | Bingler, Arnold | Bilicz, Sándor | Pávó, József

Article Type: Research Article

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. Show more

Keywords: Carbon fiber reinforced plastic, conductivity tensor, eddy current testing, finite element method

DOI: 10.3233/JAE-230142

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 397-403, 2024

Authors: Zhang, Yuange | Pei, Cuixiang | Deng, Jie | Liu, Tianhao | Chen, Hong-En | Chen, Zhenmao

Article Type: Research Article

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. Show more

Keywords: TBCs, EMAT, Rayleigh wave, delamination, numerical analysis

DOI: 10.3233/JAE-230147

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 405-413, 2024

Authors: Deng, Jie | Pei, Cuixiang | Zhang, Yuange | Qu, Yinqiang | Deng, Ke | Chen, Hong-En | Chen, Zhenmao

Article Type: Research Article

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. Show more

Keywords: Updated SAFT, array pickup EMAT, surface wave, subsurface defects

DOI: 10.3233/JAE-230148

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 415-428, 2024

Authors: Chen, Rongli | Zheng, Xiupeng | Li, Xudong | Qiao, Liang | Deng, Jie | Chen, Hong-En | Yang, Juancheng | Chen, Zhenmao

Article Type: Research Article

Abstract: It is important to measure the global and/or local velocity of an in-pipe metallic flow to control its running state in applications such as a Tokamak fusion reactor. The magnetic field outside the pipe wall will be perturbed by the motion induced eddy current when the liquid metal flows across an applied static magnetic field. This phenomenon gives a possibility to evaluate the in-pipe velocity from the measured magnetic field perturbation signals. In this paper, a non-intrusive velocity evaluation method is proposed accordingly for measuring the velocity of liquid metal through measurement and inversion of the magnetic field surrounding the …pipe. An efficient forward simulation method to calculate the magnetic field near a metallic flow in a static environmental magnetic field is developed at first. An inversion scheme based on the singular value decomposition and the L-curve method is then proposed to reconstruct the velocity distribution at a pipe cross-section with the linear equations correlating the flow velocity and the magnetic field regulated using the Tikhonov method. The reconstruction results of pipe flows of different velocity modes verified the feasibility and efficiency of the proposed velocity measurement method for in-pipe metallic flows. Show more

Keywords: Liquid metal, velocity distribution, magnetic field measurement, inverse analysis

DOI: 10.3233/JAE-230149

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 429-439, 2024

Authors: Tamburrino, Antonello | Mottola, Vincenzo

Article Type: Research Article

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 J n 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 J n , 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 J n on ∂ 𝛺 requires a negligible computational effort, and the reconstructions require only one forward problem. Show more

Keywords: Inverse problems, electrical resistance tomography, non-iterative imaging method, NtD

DOI: 10.3233/JAE-230167

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 441-446, 2024

Authors: Reboud, Christophe | Vigneron, Audrey | Skarlatos, Anastassios

Article Type: Research Article

Abstract: Infrared thermography is an imaging technique that can be used to inspect materials for flaws and various degradations in a non destructive way. In this work, we focused on the use of fast models to recover information about the material properties from experimental measurements recorded over time. Two different modelling approaches are compared to each other and to experimental data acquired on a composite plate. Then, the model based inverse problem consisting in estimating the plate properties is discussed.

Keywords: Infrared thermography, composite material, plate thinning

DOI: 10.3233/JAE-230170

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 74, no. 4, pp. 447-453, 2024