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 changesin 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.
{"title":"Effect of shielding of eddy current probes on the sensitivity for sweep frequency measurements","authors":"Arjun A.R., B. Sasi, Anish Kumar","doi":"10.3233/jae-230138","DOIUrl":"https://doi.org/10.3233/jae-230138","url":null,"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 changesin 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.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139084287","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}
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.
{"title":"Coupled electric circuits method applied to pulsed eddy current NDT problem","authors":"Ferroudja Bouali, Hassane Mohellebi","doi":"10.3233/jae-230141","DOIUrl":"https://doi.org/10.3233/jae-230141","url":null,"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.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139210612","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}
Several researches have confirmed the possibility of localizing small anomalies via Kirchhoff migration (KM); however, when the background information is unknown, small anomalies cannot be satisfactorily retrieved. This fact can be examined through the simulation results; however, related theoretical result to explain the reason of such phenomenon has not yet been investigated. In this contribution, we show that the imaging function of the KM can be expressed by an infinite series of the Bessel function of the first kind, material properties, and antenna arrangement, and applied alternative value of the background wavenumber. Based on the theoretical result, we explain why the exact location and shape of anomalies cannot be retrieved. The simulation results with synthetic data exhibited to support the theoretical result.
一些研究已经证实了通过基尔霍夫迁移（KM）定位微小异常的可能性；然而，当背景信息未知时，微小异常无法令人满意地检索出来。这一事实可以通过仿真结果来检验，但解释这种现象原因的相关理论结果尚未得到研究。在本文中，我们证明了 KM 的成像函数可以用贝塞尔函数第一类、材料特性和天线布置的无穷级数来表示，并应用了背景波数的替代值。基于这一理论结果，我们解释了为何无法获取异常点的确切位置和形状。合成数据的仿真结果表明理论结果是正确的。
{"title":"Real-time identification of small anomalies from scattering matrix without background information","authors":"Won-Kwang Park","doi":"10.3233/jae-230113","DOIUrl":"https://doi.org/10.3233/jae-230113","url":null,"abstract":"Several researches have confirmed the possibility of localizing small anomalies via Kirchhoff migration (KM); however, when the background information is unknown, small anomalies cannot be satisfactorily retrieved. This fact can be examined through the simulation results; however, related theoretical result to explain the reason of such phenomenon has not yet been investigated. In this contribution, we show that the imaging function of the KM can be expressed by an infinite series of the Bessel function of the first kind, material properties, and antenna arrangement, and applied alternative value of the background wavenumber. Based on the theoretical result, we explain why the exact location and shape of anomalies cannot be retrieved. The simulation results with synthetic data exhibited to support the theoretical result.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139555504","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}
Qing Liu, Ruihuan Ge, Li Wang, Tianming Ren, Ming Feng
A single-structured hybrid gas-magnetic bearing (HGMB) has been proposed for frequent start/stop occasions, which eliminates foil structures or static pressure systems by using the closed magnetic poles of the active magnetic bearing (AMB) as the bushing of the gas bearing. This allows the proposedbearing to realize the functions of both AMB and gas bearing with a single bearing structure. In this paper, the bias currents of AMB, aimed for enhanced load capacity and dynamic characteristics, are omitted to reduce power consumption and heat. The combination of zero-bias AMB and rigid self-acting gas bearing in a single bearing structure is therefore proposed. The rotor orbits of gas bearing, AMB, single-structured HGMB, and single-structured zero-bias HGMB in conditions of varied horizontal and vertical external loads are simulated. The dynamic performances during the run-up processes of AMB, HGMB, and zero-bias HGMB are investigated. The electromagnetic forces of each kind of bearing are compared. Numerical results demonstrate that by applying the single-structured zero-bias HGMB, the power consumption can be significantly reduced in contrast with pure AMB and single-structured HGMB. The reduced load capacity and dynamic characteristics of zero-bias AMB can be compensated by the rigid self-acting gas bearing, making the single-structured zero-bias HGMB an ideal candidate for cryogenic, ultra-high speed as well as frequent start/stop occasions.
针对频繁启动/停止的场合，我们提出了一种单一结构的混合气磁轴承（HGMB），通过使用主动磁轴承（AMB）的闭合磁极作为气体轴承的衬套，消除了箔结构或静压系统。这使得所提出的轴承能够以单一轴承结构实现主动磁轴承和气体轴承的功能。本文省略了旨在提高负载能力和动态特性的 AMB 偏置电流，以降低功耗和发热量。因此，本文提出将零偏置 AMB 和刚性自力式气体轴承结合在一个轴承结构中。模拟了气体轴承、AMB、单一结构 HGMB 和单一结构零偏置 HGMB 在不同水平和垂直外部载荷条件下的转子轨道。研究了 AMB、HGMB 和零偏置 HGMB 运行过程中的动态性能。比较了每种轴承的电磁力。数值结果表明，与纯 AMB 和单一结构的 HGMB 相比，应用单一结构的零偏置 HGMB 可以显著降低功耗。刚性自力式气体轴承可以弥补零偏置 AMB 载荷能力和动态特性的不足，从而使单结构零偏置 HGMB 成为低温、超高速和频繁启停场合的理想选择。
{"title":"Single-structured zero-bias hybrid gas-magnetic bearing and its rotordynamic performance","authors":"Qing Liu, Ruihuan Ge, Li Wang, Tianming Ren, Ming Feng","doi":"10.3233/jae-230042","DOIUrl":"https://doi.org/10.3233/jae-230042","url":null,"abstract":"A single-structured hybrid gas-magnetic bearing (HGMB) has been proposed for frequent start/stop occasions, which eliminates foil structures or static pressure systems by using the closed magnetic poles of the active magnetic bearing (AMB) as the bushing of the gas bearing. This allows the proposedbearing to realize the functions of both AMB and gas bearing with a single bearing structure. In this paper, the bias currents of AMB, aimed for enhanced load capacity and dynamic characteristics, are omitted to reduce power consumption and heat. The combination of zero-bias AMB and rigid self-acting gas bearing in a single bearing structure is therefore proposed. The rotor orbits of gas bearing, AMB, single-structured HGMB, and single-structured zero-bias HGMB in conditions of varied horizontal and vertical external loads are simulated. The dynamic performances during the run-up processes of AMB, HGMB, and zero-bias HGMB are investigated. The electromagnetic forces of each kind of bearing are compared. Numerical results demonstrate that by applying the single-structured zero-bias HGMB, the power consumption can be significantly reduced in contrast with pure AMB and single-structured HGMB. The reduced load capacity and dynamic characteristics of zero-bias AMB can be compensated by the rigid self-acting gas bearing, making the single-structured zero-bias HGMB an ideal candidate for cryogenic, ultra-high speed as well as frequent start/stop occasions.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683916","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}
A multi-mode wideband antenna based on multi-mode resonator is proposed with stable radiation patterns, which is composed of metal radiators, parasitic resonators, shorted patches fed by the U-shaped feedline, and a box-shaped reflector. A prototype of the proposed antenna is designed, fabricated,and tested. Measured results show that the antenna achieves an impedance bandwidth of 37.5% (0.67–0.98 GHz) for |S11| < −15 dB, a half-power beam width (HPBW) of 67.5 ± 2.4 degree at H-plane (horizontal plane), and a gain of 8.0 ± 0.5 dBi. Furthermore, the cross-polarization discrimination (XPD) is more than 15 dB at 0 degrees and at least 11.2 dB within ±60 degrees at H-plane, respectively. The proposed antenna can be used in the modern communication systems for LTE700/GSM850/GSM900.
{"title":"Multi-mode wideband antenna based on multi-mode resonator","authors":"Rui Wu, Jianhong Lin, Shuting Cai","doi":"10.3233/jae-230116","DOIUrl":"https://doi.org/10.3233/jae-230116","url":null,"abstract":"A multi-mode wideband antenna based on multi-mode resonator is proposed with stable radiation patterns, which is composed of metal radiators, parasitic resonators, shorted patches fed by the U-shaped feedline, and a box-shaped reflector. A prototype of the proposed antenna is designed, fabricated,and tested. Measured results show that the antenna achieves an impedance bandwidth of 37.5% (0.67–0.98 GHz) for |S11| < −15 dB, a half-power beam width (HPBW) of 67.5 ± 2.4 degree at H-plane (horizontal plane), and a gain of 8.0 ± 0.5 dBi. Furthermore, the cross-polarization discrimination (XPD) is more than 15 dB at 0 degrees and at least 11.2 dB within ±60 degrees at H-plane, respectively. The proposed antenna can be used in the modern communication systems for LTE700/GSM850/GSM900.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138503711","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 small antenna is proposed to diagnose skin sarcoma at an embryonic stage. The antenna has an area of 30.54 × 15.27 mm2 and resonates at 1429 MHz with a reflection coefficient of −17.64 dB. The structure consists of a 35 μm copper sheet etched on a 1.6 mm FR-4 substrate. The diagnosis is based on the resonance frequency shift, and the SAR (Specific Absorption Rate) variation when the antenna is positioned on malignant tissue. For the simulations, a three-layer body phantom (skin, fat, muscle), and a half-sphere tumor phantom were considered. Simulations of the antenna performances showed that for a tumor of 100 μm, the resonant frequency, and the SAR decrease by 2 MHz, and 1.09 mW/Kg, respectively. In addition to sarcoma detection, the antenna’s 3.6 dBi gain allows for 124.47 m biomedical communication links in a complex environment.
{"title":"Skin sarcoma stage detection using antenna resonant scale","authors":"Dozohoua Silue, Mondher Labidi, Fethi Choubani","doi":"10.3233/jae-230048","DOIUrl":"https://doi.org/10.3233/jae-230048","url":null,"abstract":"In this paper, a small antenna is proposed to diagnose skin sarcoma at an embryonic stage. The antenna has an area of 30.54 × 15.27 mm2 and resonates at 1429 MHz with a reflection coefficient of −17.64 dB. The structure consists of a 35 μm copper sheet etched on a 1.6 mm FR-4 substrate. The diagnosis is based on the resonance frequency shift, and the SAR (Specific Absorption Rate) variation when the antenna is positioned on malignant tissue. For the simulations, a three-layer body phantom (skin, fat, muscle), and a half-sphere tumor phantom were considered. Simulations of the antenna performances showed that for a tumor of 100 μm, the resonant frequency, and the SAR decrease by 2 MHz, and 1.09 mW/Kg, respectively. In addition to sarcoma detection, the antenna’s 3.6 dBi gain allows for 124.47 m biomedical communication links in a complex environment.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683998","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}
Prashanth Baskaran, Helena Geirinhas Ramos, Artur Lopes Ribeiro
Probability of Detection (PoD) models, in general, take into consideration one or multiple flaw parameters such as its length, maximum depth, and/or maximum surface area, and one flaw signal. However, due to correlation between the response signals, it might be necessary to consider multiple flaw response signals simultaneously. Hence, in this work, we demonstrate the possibility of including multiple correlated flaw signals, features, towards the construction of a PoD curve. The flaw features considered are the 3 components of the magnetic flux density. This is a simulation based PoD estimation for a narrow opening notch type flaw located in the sub-surface of a two-layer geometry. The inspection is carried out by an uniform eddy current probe that induces a spatially uniform fields into the conducting space, around the region of interest. The analysis was performed using the semi-analytical boundary element method (BEM).
检测概率（PoD）模型一般考虑一个或多个缺陷参数，如长度、最大深度和/或最大表面积，以及一个缺陷信号。然而，由于响应信号之间存在相关性，可能有必要同时考虑多个缺陷响应信号。因此，在这项工作中，我们展示了将多个相关缺陷信号（特征）纳入 PoD 曲线构建的可能性。考虑的缺陷特征是磁通密度的 3 个分量。这是对位于双层几何体次表层的窄开口缺口型缺陷进行的基于模拟的 PoD 估算。检测是通过一个均匀的涡流探头进行的，该探头会在相关区域周围的导电空间中产生一个空间均匀的磁场。分析采用半解析边界元法（BEM）进行。
{"title":"Evaluation of the detectability of flaws in a two layer structure – A simulation-based PoD study incorporating correlated variables","authors":"Prashanth Baskaran, Helena Geirinhas Ramos, Artur Lopes Ribeiro","doi":"10.3233/jae-230134","DOIUrl":"https://doi.org/10.3233/jae-230134","url":null,"abstract":"Probability of Detection (PoD) models, in general, take into consideration one or multiple flaw parameters such as its length, maximum depth, and/or maximum surface area, and one flaw signal. However, due to correlation between the response signals, it might be necessary to consider multiple flaw response signals simultaneously. Hence, in this work, we demonstrate the possibility of including multiple correlated flaw signals, features, towards the construction of a PoD curve. The flaw features considered are the 3 components of the magnetic flux density. This is a simulation based PoD estimation for a narrow opening notch type flaw located in the sub-surface of a two-layer geometry. The inspection is carried out by an uniform eddy current probe that induces a spatially uniform fields into the conducting space, around the region of interest. The analysis was performed using the semi-analytical boundary element method (BEM).","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138683910","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}
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.
{"title":"Development of a steel health monitoring device based on anisotropic magnetoresistance sensors","authors":"Georgia Stamou, Spyridon Angelopoulos, Evangelos Hristoforou","doi":"10.3233/jae-230137","DOIUrl":"https://doi.org/10.3233/jae-230137","url":null,"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.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138503710","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}
Shanyi Jiang, Xinliang Pang, Yunfen Chang, Jie Cui, Yubing Han
Abstract
In this study, we investigated the coupling features of the nuclear electromagnetic pulse (NEMP) on overhead cables in the middle-and-far regions, different from the transmission line model commonly used for field-line coupling in high-frequency cases, using a simpler lumped approximation to solve the electrically small size model in low-frequency cases. To verify its effectiveness, a simulation model with the same conditions was set up using the software of Computer Simulation Technology (CST), and cable coupling experiments were performed in a laboratory environment using a bounded-wave electromagnetic pulse simulator. The calculated results of the lumped approximation circuit were compared with the CST simulation and measured results, and the agreement was good. The results also shows that the load exhibits a differential response in the case of the low impedance and it is consistent with the excitation signal in the case of the high impedance. Finally, some more experiments were constructed to analyzed the effect of different cable parameters on the cable load response through experiments, and the experimental results are also in general agreement with the theoretical analysis, in which the induced signal of the low-impedance load is mainly determined by the magnetic field in the direction normal to the cable and the ground loop and the induced signal of the high-impedance load is mainly determined by the electric field in the direction of the height of the cable erection.
{"title":"Analysis on the low-frequency electromagnetic pulse coupling to horizontal electrically short lines","authors":"Shanyi Jiang, Xinliang Pang, Yunfen Chang, Jie Cui, Yubing Han","doi":"10.3233/jae-230010","DOIUrl":"https://doi.org/10.3233/jae-230010","url":null,"abstract":"<h4><span>Abstract</span></h4><p>In this study, we investigated the coupling features of the nuclear electromagnetic pulse (NEMP) on overhead cables in the middle-and-far regions, different from the transmission line model commonly used for field-line coupling in high-frequency cases, using a simpler lumped approximation to solve the electrically small size model in low-frequency cases. To verify its effectiveness, a simulation model with the same conditions was set up using the software of Computer Simulation Technology (CST), and cable coupling experiments were performed in a laboratory environment using a bounded-wave electromagnetic pulse simulator. The calculated results of the lumped approximation circuit were compared with the CST simulation and measured results, and the agreement was good. The results also shows that the load exhibits a differential response in the case of the low impedance and it is consistent with the excitation signal in the case of the high impedance. Finally, some more experiments were constructed to analyzed the effect of different cable parameters on the cable load response through experiments, and the experimental results are also in general agreement with the theoretical analysis, in which the induced signal of the low-impedance load is mainly determined by the magnetic field in the direction normal to the cable and the ground loop and the induced signal of the high-impedance load is mainly determined by the electric field in the direction of the height of the cable erection. </p>","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138684006","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}
Paolo Di Barba, Fabrizio Dughiero, Michele Forzan, David A. Lowther, Antonio Marconi, Maria Evelina Mognaschi, Jan K. Sykulski
The authors explore the possibility of applying a convolutional Naeural Network (CNN) to the solution of coupled electromagnetic and thermal problem, focusing on the classical problem of induction heating systems, traditionally solved by resorting to Finite Element (FE) models. In fact, FE modelling is widely used in the design of induction heating systems due its accuracy, even if the solution of a coupled nonlinear problem is expensive in terms of computational time and hardware resources, notably in 3D analysis. A model based on CNN could be an interesting alternative; in fact, CNN is a learning model selected for its excellent ability to converge, even when trained with a limited dataset. CNNs are able to treat images as input and they are used here as follows: given a temperature map in the workpiece, identify the corresponding vector of current, frequency and process heating time; this mapping is a model of the inverse induction heating problem. Specifically, we consider as an example the induction heating of a cylindrical steel billet, made of C45 steel, placed in a solenoidal inductor coil exhibiting the same axial length of the billet (TEAM 36 problem). A thorough heating process is usually applied before hot working of the billet, as in an extrusion process, but this methodology can be applied also in the design of induction hardening processes. First, a CNN has been trained from scratch by means of a dataset of FE solutions of coupled electromagnetic and thermal problems. For the sake of a comparison, a transfer learning technique is applied using GoogLeNet, i.e. a Deep Convolutional Neural Network able to classify images: starting from the pre-trained GoogLeNet, its training has been subsequently refined with the dataset of solutions from FE analyses. When the training dataset contains a limited number of samples, GoogleNet shows good accuracy in predicting the process parameters; in the case of a high number of samples in the training set, namely beyond a threshold like e.g. 1500, both CNNs show good accuracy of the result.
{"title":"Neural metamodels and transfer learning for induction heating processes (TEAM 36 problem)","authors":"Paolo Di Barba, Fabrizio Dughiero, Michele Forzan, David A. Lowther, Antonio Marconi, Maria Evelina Mognaschi, Jan K. Sykulski","doi":"10.3233/jae-230087","DOIUrl":"https://doi.org/10.3233/jae-230087","url":null,"abstract":"The authors explore the possibility of applying a convolutional Naeural Network (CNN) to the solution of coupled electromagnetic and thermal problem, focusing on the classical problem of induction heating systems, traditionally solved by resorting to Finite Element (FE) models. In fact, FE modelling is widely used in the design of induction heating systems due its accuracy, even if the solution of a coupled nonlinear problem is expensive in terms of computational time and hardware resources, notably in 3D analysis. A model based on CNN could be an interesting alternative; in fact, CNN is a learning model selected for its excellent ability to converge, even when trained with a limited dataset. CNNs are able to treat images as input and they are used here as follows: given a temperature map in the workpiece, identify the corresponding vector of current, frequency and process heating time; this mapping is a model of the inverse induction heating problem. Specifically, we consider as an example the induction heating of a cylindrical steel billet, made of C45 steel, placed in a solenoidal inductor coil exhibiting the same axial length of the billet (TEAM 36 problem). A thorough heating process is usually applied before hot working of the billet, as in an extrusion process, but this methodology can be applied also in the design of induction hardening processes. First, a CNN has been trained from scratch by means of a dataset of FE solutions of coupled electromagnetic and thermal problems. For the sake of a comparison, a transfer learning technique is applied using GoogLeNet, i.e. a Deep Convolutional Neural Network able to classify images: starting from the pre-trained GoogLeNet, its training has been subsequently refined with the dataset of solutions from FE analyses. When the training dataset contains a limited number of samples, GoogleNet shows good accuracy in predicting the process parameters; in the case of a high number of samples in the training set, namely beyond a threshold like e.g. 1500, both CNNs show good accuracy of the result.","PeriodicalId":50340,"journal":{"name":"International Journal of Applied Electromagnetics and Mechanics","volume":null,"pages":null},"PeriodicalIF":0.6,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138503696","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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