International Journal of Applied Electromagnetics and Mechanics - Volume 19, issue 1-4

Authors: Wang, Feng | Tanaka, Mami | Nakada, Naoto | Hayase, Tsuyoshi | Chonan, Seiji

Article Type: Research Article

Abstract: This paper is a study on the development of an active damper for the couplers of railway cars using electrorheological (ER) fluid as a functional material with the purpose of lowering the coupler force between a relief and a failed train set, which is a very important design factor for the structure of the super express bullet train. A prototype damper is fabricated, which consists of a hydraulic cylinder, an ER bypass slit valve and a PID controller. …The buffering force is developed in the ER fluid both through the bypass slit and at the piston-cylinder gap and controlled by adjusting the applied electric field to the ER fluid. Function of the damper is tested through experiments on control the buffering force under various running conditions. Show more

Keywords: electrorheological fluid, active damper, railway car, coupler, buffering force

DOI: 10.3233/JAE-2004-575

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 269-274, 2004

Authors: Choi, Jae-hak | Lee, Ju | Kim, Youn-hyun

Article Type: Research Article

Abstract: This paper presents a design scheme to minimize torque ripple in 6/4 Switched Reluctance Motor (SRM) using transient Finite Element Analysis (FEA) in which the magnetic field is combined with a driving circuit. Pole arcs and switching angles are major design factors. If these design factors are considered independently, the enhancement of SRM performance is restricted. Therefore this paper proposes not only optimal combination of stator pole arc and rotor pole arc but also the turn-on …and turn-off angles as a function of pole arcs. Especially, turn-on and turn-off angle are formulated from a voltage equation and feasible design ranges are suggested with variable speed. Show more

Keywords: switched reluctance motor, finite element method, torque ripple

DOI: 10.3233/JAE-2004-576

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 275-279, 2004

Authors: Gyselinck, Johan | Dular, Patrick

Article Type: Research Article

Abstract: The authors present a novel lumped model for laminated cores considering the 1D eddy current problem in a conducting ferromagnetic lamination. The model is based on a polynomial spatial expansion of the induction and the magnetic field throughout the thickness of the lamination, of order n and n+2 respectively, such that the governing partial differential equation is satisfied (for any n≥0). The magnetic constitutive law is weakly imposed, leading to a system …of 1+n/2 nonlinear differential equations. The method is elaborated and validated for both the linear and the nonlinear case. A fast convergence towards the exact solution (n=∞) is observed when increasing n. Show more

Keywords: laminated core, eddy currents, skin effect, finite element method

DOI: 10.3233/JAE-2004-577

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 281-285, 2004

Authors: Kim, Tae Heoung | Lee, Ju

Article Type: Research Article

Abstract: In this paper, we introduce the analysis method of Brushless DC Motor (BLDCM) with long commutation period and large DC link voltage ripple using time-stepped voltage source Finite Element Method (FEM), and investigate the influence on motor performance such as torque ripple and radial force due to signal distortion of the position sensor and DC link voltage ripples. Simulation and experimental results are also presented to verify the proposed analysis method.

Keywords: BLDC, FEM, feedback diode, position sensor

DOI: 10.3233/JAE-2004-578

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 287-291, 2004

Authors: Daniel, Laurent | Hubert, Olivier | Billardon, René

Article Type: Research Article

Abstract: The magnetostriction strain is very sensitive to crystallographic texture, even for quasi-isotropic materials. A multiscale approach has been proposed to model the phenomena, taking into account the usual cubic anisotropy at the grain scale, and the heterogeneous orientation of the grains at macro scale. Experimental and modelled data are in good agreement for uncoupled properties. It is shown that a specific demagnetising surface effect must be taken into account in the description of the anisotropy to …improve the modelling of magnetostriction. Show more

Keywords: magnetostriction, multiscale modelling, demagnetising surface effect

DOI: 10.3233/JAE-2004-579

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 293-297, 2004

Authors: Jennane, J. | Fadli, N. | Charpentier, J.-F. | Quesada, J. Ríos

Article Type: Research Article

Abstract: This paper deals with the study of discoidal Permanent Magnet machines using a method of field calculation based on the magnetic charges theory. This fast calculation method enables a systematic study of these devices. The presented method has been validated by a comparison with the classical FE method. Three kinds of discoidal machines are studied and compared. The first is a classical machine with axially magnetized magnets with iron stator and rotor cores. The second and …third use simple Halbach array configurations for the magnets with iron and ironless rotor core. This study illustrates the interest of the Halbach structures for this type of device. Show more

Keywords: axial flux, permanent magnet, analytical study

DOI: 10.3233/JAE-2004-580

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 299-302, 2004

Authors: Luo, Yun | Yakuma, Kumiko | Takagi, Toshiyuki | Maruyama, Shigenao

Article Type: Research Article

Abstract: This paper investigates the thermal responses of a shape memory alloy (SMA) manipulator driven by thermoelectric modules. We propose the use of heat transfer by thermoelectric modules for fast cooling and thermal control of the SMA manipulator in various temperature ranges. The approaches to enlarge the applicable temperature range of the SMA manipulator have been discussed based on the numerical simulation.

Keywords: thermoelectric modules, shape memory alloys, thermal response

DOI: 10.3233/JAE-2004-581

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 303-307, 2004

Authors: Kojima, Fumio | Ito, Kazufumi

Article Type: Research Article

Abstract: This paper is concerned with computational and regularization techniques for recovering induced magnetic fields due to the existence of cracks. The problem is formulated as an inverse problem with a set of source functions of the distribution type. The regularization of bounded variation is effectively used for solving the severe ill-posed problem. A iterative solver is proposed by a integro-differential equation with time marching scheme. For the practical implementation of the numerical treatment, a finite difference …scheme is adopted to the proposed method with the aid of discrete fast Fourier transform. Some successful numerical experiments are demonstrated for the validity of the proposed method. Show more

Keywords: inverse problem, regularization, fast Fourier transform

DOI: 10.3233/JAE-2004-582

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 309-313, 2004

Authors: Watanabe, Takashi | Todaka, Takashi | Enokizono, Masato

Article Type: Research Article

Abstract: This paper presents a new finite element formulation using overlap grid coordinate system for eddy current problems. In order to solve eddy current problems that consist of several conductive objects moving in magnetic field in any directions, we have to remesh the region under consideration according to those positions in the step-by-step computation. To reduce the computation time, a composite mesh scheme is introduced into such eddy current problems. The results obtained in the verification show …usefulness of this method in eddy current problems consisting several moving conductors. Show more

DOI: 10.3233/JAE-2004-583

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 315-320, 2004

Authors: Bonnet, Pierre | Vernet, Raphaël

Article Type: Research Article

Abstract: This paper deals with a numerical FDTD approach to solve a particular ground-penetrating problem. Classical Yee FDTD formulation is used to simulate layered media on a perfectly electrically conductive plate (PEC). It is shown that an alternative of the step 3-D PML formulated by Sullivan is well adaptated to surround the computational domain. In particular, the PEC can be easily extended to the PML medium without any extra reflection error.

Keywords: PML, FDTD, PEC, soil

DOI: 10.3233/JAE-2004-584

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 19, no. 1-4, pp. 321-325, 2004