International Journal of Applied Electromagnetics and Mechanics - Volume 57, issue 2

Authors: Versaci, Mario | La Foresta, Fabio | Morabito, Francesco Carlo | Angiulli, Giovanni

Article Type: Research Article

Abstract: This work is devoted to solve the problem of the determination of the spatial position, orientation and size of an electrically charged ellipsoidal conductor subjected to an external electric field. The problem, which is relevant to the field of the non destructive testing and evaluations engineering, is approached in fuzzy domain replacing it in an equivalent classification problem between images through the use of the fuzzy divergence concept. The obtained numerical results demonstrate how the performances of the proposed approach are totally comparable with those given by the more sophisticate and well established fuzzy clustering techniques exploited in literature, offering …thus a viable alternative to solve identification problem in electrostatics. Show more

Keywords: Inverse problems, NDT/NDE, fuzzy logic, fuzzy divergences

DOI: 10.3233/JAE-170043

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 133-146, 2018

Authors: Du, Chao | Meng, Dawei

Article Type: Research Article

Abstract: Double-sided-moving-magnet ring-winding permanent magnet linear synchronous motors (DSMM-R-PMLSMs) offer high thrust density and power factor, light mover quality, strong structure, segmented control, and powering convenience making them the favored choice for use as electromagnetic launch systems. In this paper, we analyze the mover magnetic field and propose a DSMM-R-PMLSM with a new mover structure with the aim of achieving a large thrust and high acceleration in the linear motor. The dynamic characteristics are obtained by setting up a mathematical model of this motor type, and the thrust performances of movers with different structures under normal and eccentric operation are compared …and then rationalized by field-circuit combined analysis and separate prototype tests. The results show that the new mover structure lends the linear motor the merits of higher electromagnetic thrust, lighter mover quality and better acceleration, thereby providing a reference for future research on linear motors for electromagnetic launch systems. Show more

Keywords: Electromagnetic launch system, permanent magnet linear synchronous motor, double-sided mover structure, field-circuit combined analysis, thrust performance

DOI: 10.3233/JAE-170123

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 147-164, 2018

Authors: Chen, Fubin | Gao, Jinchun | Tian, Wenjie

Article Type: Research Article

Abstract: The quartz resonator can be used as a force-sensitive element for sensors. The resonance energy distribution of thickness-shear quartz crystal is derived and calculated using the energy trapping theory. To reduce temperature and other interference factors as well as improve force-sensitivity, a multi-electrode force-sensitive resonator cluster is designed based on resonance energy distribution results. The output frequency signals of the resonator cluster are subtracted from each other to form beat frequency signals to suppress the temperature and other interference factors using the common mode rejection principle. Next, the beat frequency signals are superimposed to improve the overall force-sensitivity of the …quartz crystal resonator cluster. The experimental results show that the temperature characteristics of the quartz resonator cluster are better than the traditional single electrode resonator and that the frequency stability reaches 10 - 10 orders of magnitude. The overall force-frequency coefficient of the resonator cluster increases to 9992 Hz/N. Show more

Keywords: Quartz force-sensitive resonator cluster, thickness-shear quartz crystal, energy trapping

DOI: 10.3233/JAE-170133

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 165-175, 2018

Authors: Xu, Xiaojuan | Ji, Hongli | Qiu, Jinhao | Takagi, Toshiyuki

Article Type: Research Article

Abstract: The applicability of conventional eddy current (EC) testing to detect delamination in laminates of carbon fiber reinforced polymers (CFRP) was assessed. As delamination impedes the induced currents flowing across the layers, the EC technique offers the potential for delamination in CFRPs to be detected by sensing the change in probe output signals caused by distortions in the magnetic field. In a numerical study, ECs distribution in CFRPs alters considerably in multidirectional and cross-ply laminates and currents drop steeply when delamination is present. In experiments, the detectability of delamination at different depths was investigated using 24-layer laminates, each with different stacking …sequences. The change in amplitude of the probe output signal obtained from data agrees qualitatively with the numerical analysis. The size and location of the delamination defect were compared with those obtained in ultrasonic scanning images. Experiments show that delamination at a maximum depth of 0.75 mm in cross-ply samples could be detected, whereas subsurface defects in the unidirectional plate went undetected. Show more

Keywords: Conventional eddy current testing, carbon fiber reinforced polymer, delamination detection

DOI: 10.3233/JAE-170136

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 177-192, 2018

Authors: Witczak, Pawel | Kubiak, Witold | Swiniarski, Jacek

Article Type: Research Article

Abstract: The paper presents the combined results of numerical analyses of magnetic vibration introduced by the rotor eccentricity in permanent magnet motor with concentrated windings. The analysis is carried for two possible rotor displacements – uniform shift of its axis against stator and twist of that axis about the gravity point. The investigations were obtained by means of finite elements approach, both in electromagnetic and mechanical domain. The influence of these on magnitude and form of forced vibration is also considered.

Keywords: Permanent magnet motor, vibration, eccentricity, finite elements, spectral analysis

DOI: 10.3233/JAE-170144

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 193-203, 2018

Authors: Zhang, Jianping | Zha, Zhenting | Che, Peng | Pan, Weiguo | Liu, Jiang

Article Type: Research Article

Abstract: Aiming at improving the trapping performance of submicron particles, the magnetic field was introduced into the outer vortex electrostatic cyclone (ESC), and the dust-removal mechanism under the action of electromagnetic field was investigated. Besides, the theoretical model was established to analyze the interaction between fluid flow field, electromagnetic field and particle dynamic field, and the influences of magnetic field on submicron particles collection efficiency at different working voltages and gas velocities were simulated and discussed. The results indicate that the introduction of magnetic field obviously enhances the ESC trapping performance for submicron particles. High working voltage and low gas velocity at a …given magnetic flux density are both more favorable for trapping submicron particles, but the magnetic field effect is more obvious at high gas velocity, as well as at low working voltage. Furthermore, at the same working voltage and gas velocity, the contribution of magnetic field to collection efficiency increases with the applied magnetic flux density increased, but the increment gradually decreases, which can lay significant foundation for optimal design of submicron particles removal in ESC. Show more

Keywords: Applied magnetic field, electrostatic cyclone, submicron particles, removal mechanism, trapping performance

DOI: 10.3233/JAE-170145

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 205-215, 2018

Authors: Chen, Hanbo | Li, Tonglin | Shi, Huiyan | Wang, Heng | Li, Shaopeng

Article Type: Research Article

Abstract: This paper presents a second order edge-based finite element method based on a new type of second order edge element for numerical modeling of 3D controlled source electromagnetic data in an anisotropic conductive medium. We adopt the anomalous potential field formulation to avoid the effect of source’s singularity. The computational domain was subdivided into unstructured tetrahedral elements. The sparse linear system was solved using the Induced dimensional reduction (IDR(s)) method with an incomplete LU preconditioner. We have applied the developed algorithm to compute a typical MCSEM response over several 3D models, we compare the numerical results from our method and …FEM solution based on conventional first and second order element. The results of comparison shown that our algorithm can significantly reduce the computation cost without loss to much accuracy. Show more

Keywords: Marine controlled sources electromagnetic method, second order element, edge-based finite element method, anisotropic, modeling

DOI: 10.3233/JAE-170153

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 217-233, 2018

Authors: Vértesy, G. | Tomáš, I. | Bálint, B. | Gyimóthy, Sz. | Pávó, J. | Uchimoto, T. | Takagi, T.

Article Type: Research Article

Abstract: Detectability of an artificial slot, placed at the bottom of a steel plate was investigated by the method of Magnetic adaptive testing (MAT), when the measurement was performed through another steel plate. Influence of an air gap (or of a nonmagnetic spacer) located either between the magnetizing yoke and the top plate surface or between the two plates was explored. It was found that if the thickness of the nonmagnetic spacer was not larger than 0.15 mm, it had no influence on the detectability of the slot in the given geometry. This result shows an excellent applicability of MAT, and …it is encouraging for possible future practical applications. The empirical data were compared with results of an electromagnetic simulation, and the outcome was interpreted and explained. Show more

Keywords: Local wall thinning, magnetic NDT, magnetic adaptive testing, nonmagnetic spacer

DOI: 10.3233/JAE-180002

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 235-245, 2018

Authors: Bai, Yaxiang | Luan, Zhongqi

Article Type: Research Article

Abstract: To reduce the vacuum freeze drying time and to decrease the energy consumption of sea cucumber drying, the vacuum freeze drying experiments for sea cucumber pretreated by a high-pulsed electric field (HPEF) were carried out. The effects of HPEF pretreatment on the drying time, energy consumption, and the shrinkage, rehydration rate, protein content, texture and acid mucopolysaccharide of the samples were determined to compare with those of control group. The results indicated that HPEF pretreatment can significantly reduce the drying time of sea cucumber, save drying energy and improve the rehydration rate of sea cucumber. Compared with control group, the …samples treated by HPEF have no statistically significant difference in terms of shrinkage, texture, protein and acid mucopolysaccharide content. And, By a needle electrode, under applied voltages of 22.5 kV and frequency of 70 Hz, the drying time could be reduced 16.43%, the energy consumption could be saved 15.64%, and, the rehydration rate of dried samples could be improved 11.7%. This suggests an application potential for HPEF pretreatment in the vacuum freeze drying of sea cucumber. Show more

Keywords: Vacuum freeze drying, high-pulsed electric field (HPEF), sea cucumber, pretreatment, rehydration rate

DOI: 10.3233/JAE-180009

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 57, no. 2, pp. 247-256, 2018