International Journal of Applied Electromagnetics and Mechanics - Volume Pre-press, issue Pre-press

Authors: Xie, Yuedong | Yin, Liyuan | Sergio, Rodriguez G. | Yang, Tiemei | Liu, Zenghua | Yin, Wuliang

Article Type: Research Article

Abstract: This paper presents a wholly analytical method which combines electromagnetic and ultrasonic simulations for the study of an Electromagnetic Acoustic Transducer Array (EMAT). Analytical solutions to the eddy current problem for the meander coil used in an EMAT are adapted from the classic Deeds and Dodd solution, which was originally intended for circular coils. The analytical solution resulting from this novel adaptation exploits the large radius extrapolation and shows several advantages over the finite element method (FEM), especially in the higher frequency regime. The calculated Lorentz force density from the EM solver is then coupled to the ultrasonic simulations, which …exploit an analytical solution for generating the distribution of surface waves. Beam features are studied, which can produce performance parameters for an EMAT array, facilitating the optimum design of such sensors. This total analytical approach to an EMAT simulation has not been reported previously to our knowledge. Show more

Keywords: Eddy current calculation, modelling and simulation, electromagnetic acoustic transducer (EMAT), analytical solutions, finite element method (FEM)

DOI: 10.3233/JAE-150137

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-15, 2016

Authors: Xiong, Qi | Huang, Hao | Deng, Changzheng | Li, Liang | Qiu, Li | Tang, Hongtao

Article Type: Research Article

Abstract: Low forming accuracy is the main defects in electromagnetic forming process of sheet metal. One of the main reasons is that shapes of the coil and required workpiece are cylindrical and deep concave respectively. The distance between the coil and the side wall of deformed sheet metal is too far in forming process, which leads to a consequence that electromagnetic force in the side wall is not enough. To solve this problem, a solenoid field shaper was introduced to enhance the electromagnetic force at the side wall, and then improve forming accuracy of electromagnetic forming of sheet metal. To verify …the effectiveness of the method, a series of simulations based on circuit-electromagnetic-structure were finished. The results showed that the maximum electromagnetic force with field shaper increased more than 10 times at the side wall. And the maximum deformation was 1.18 mm which can improve forming accuracy effectively. The presented method and results can be helpful in designing electromagnetic forming systems of sheet metal. Show more

Keywords: Electromagnetic forming, sheet metal, forming accuracy, field shaper

DOI: 10.3233/JAE-180001

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-9, 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. Pre-press, no. Pre-press, pp. 1-10, 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. Pre-press, no. Pre-press, pp. 1-17, 2018

Authors: Qiu, Li | Yu, Yijie | Wang, Ziwei | Yang, Yuqi | Yang, Yaqin | Su, Pan

Article Type: Research Article

Abstract: As a high-speed forming technology, electromagnetic forming has been more and more widely used because it can improve the material forming performance greatly. In electromagnetic forming process, the pulsed electromagnetic force generated by the coils is the load of the workpiece, hence its distribution characteristics have a great influence on the workpiece forming performance. Based on the basic principle of electromagnetic forming, this paper introduces and analyzes some latest electromagnetic forming technologies with different coil systems, including electromagnetic incremental forming, space-time-controlled multi-stage pulsed magnetic field forming, and electromagnetic tube expansion with axial compression. Aim at each forming method, the following …contents are mainly studied: 1) The key technical problems solved by this method. 2) The structure of the coil system. 3) The distribution of magnetic flux density and electromagnetic force. 4) The advantages and disadvantages of the method. Through above analysis, it is hoped that the basic idea of technological innovation in electromagnetic forming is clarified in this paper, which can provide guidance for the future innovation direction of electromagnetic forming. Show more

Keywords: Electromagnetic forming, coil system, axial electromagnetic force, radial electromagnetic force

DOI: 10.3233/JAE-170163

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-9, 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. Pre-press, no. Pre-press, pp. 1-18, 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. Pre-press, no. Pre-press, pp. 1-11, 2018

Authors: He, Wen | Tang, Bo | Jia, Shushi

Article Type: Research Article

Abstract: A novel broadband electromagnetic angular vibrator with a disk-type rotating coil is brought forward to satisfy the calibration demand of various angular vibration transducers. First, the structure of the electromagnetic angular vibrator is introduced, and the electromechanical coupling equation is established to reveal the relation between the input and output of the vibrator. Then, in order to realize wide operating frequency range and low total harmonic distortion of angular motion output, four key technologies have been adopted in our angular vibrator, which include a rotating coil made of a multilayer printed circuit board, a rotating component with a high torsional …resonant frequency, a double-magnetic-source magnetic circuit with pole shoes and a linear suspension device with large angular displacement. Finally, the performance indexes and the total harmonic distortion of output motion waveform from the developed broadband electromagnetic angular vibrator are measured. The test results show that the angular vibrator can output maximum angular displacement of 60 ∘ and maximum angular acceleration of 2000 rad⋅ s - 2 , and the total harmonic distortion of the angular acceleration waveform from the developed vibrator is less than 1% over its whole operating frequency range from 0.01 to 1200 Hz, which has met the requirement of the angular vibrator for calibration according to ISO 16063-15: 2006. Show more

Keywords: Electromagnetic, angular vibrator, rotating coil, magnetic circuit, linear suspension device

DOI: 10.3233/JAE-170132

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. Pre-press, no. Pre-press, pp. 1-13, 2018

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. Pre-press, no. Pre-press, pp. 1-14, 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. Pre-press, no. Pre-press, pp. 1-16, 2018