International Journal of Applied Electromagnetics and Mechanics - Volume 37, issue 1

Authors: Awad, Emad

Article Type: Research Article

Abstract: In this paper, some energy inequalities are developed for an unbounded perfect electrically conducting generalized thermoelastic region moving in a variable magnetic field. Sufficient restrictions on the magneto-thermoelastic moduli and solutions are given in order that the perturbations initially generated in a bounded domain of the body cannot invade the whole body. Some uniqueness results are readily proved provided that such restrictions are met.

Keywords: Domain of influence, magneto-elasticity, magneto-thermoelasticity, uniqueness, work and energy theorem

DOI: 10.3233/JAE-2011-1374

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 37, no. 1, pp. 1-18, 2011

Authors: Mahmoudi, Amin | Rahim, N.A. | Hew, W.P.

Article Type: Research Article

Abstract: This paper presents an analytical approach to calculate the magnetic field in a slotted axial-flux permanent-magnet machine. The method is modeled on a simple nonlinear magnetic analysis of an equivalent magnetic circuit with a saturation-possible magnetic-reluctance core in a slotted axial-flux permanent-magnet machine. It calculates flux distribution and torque characteristic in various operating conditions. Its accuracy and validity are verified by results that match those of a Finite Element Analysis model. This …method serves as a complementary design tool to FEA especially in expediting design optimization of an electrical machine. The method is as accurate as FEA but betters FEA with its shorter computation time, making it the better alternative in initial estimations. After verification of the analysis, sensitivity to design variables by using the proposed model is presented. The sensitivity analysis through the proposed magnetic circuit of the AFPM machine provides an effective way for selection of design parameters. These parameters are iteratively adjusted through multi-objective optimal design in order to obtain maximum output torque and efficiency. Simulation results show AFPM machine efficiency to be affected the most by its diameter, followed by magnet fraction, and the least by back-iron thickness. Show more

Keywords: Axial-flux permanent-magnet machine, finite element method, magnetic circuit

DOI: 10.3233/JAE-2011-1375

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 37, no. 1, pp. 19-34, 2011

Authors: Abdallh, Ahmed Abou-Elyazied | Crevecoeur, Guillaume | Sergeant, Peter | Dupré, Luc

Article Type: Research Article

Abstract: The identification of the magnetic material characteristics for the switched reluctance motor by solving an inverse problem is presented. The inverse problem aims at identifying the magnetic material parameter values of the magnetic circuit, starting from measured torque profiles. The computational time of the inverse problem is appreciably reduced by implementing a space mapping-based inverse approach. Using the space mapping technique, we combine the computationally intensive finite element model with a much faster magnetic …network model. The proposed approach is very helpful for the material identification problem on the electrical machine, and the obtained results reveal the success and the reliability of the proposed scheme. Show more

Keywords: Inverse problems, magnetic material identification, space mapping technique, switched reluctance motor (SRM)

DOI: 10.3233/JAE-2011-1377

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 37, no. 1, pp. 35-49, 2011

Authors: Mozetic, Halston | Fonseca, Eduardo | Schneider, Eduardo L. | Kindlein, Jr., Wilson | Schaeffer, Lírio

Article Type: Research Article

Abstract: This work presents the application of induced magnetic field during the heat treatment of Nodular Cast Iron to improve the magnetic permeability of this material in order to use it in speakers, as a lower cost alternative to the forged low carbon steel. Magnetic field annealing was carried out observing the performance of the initial magnetic permeability of the samples, and subsequently measured with field saturation equipment. The results were correlated with the data obtained from …the use of the SAE 1020 steel, with the same conditions of use and laboratory tests. Metallographic and chemical composition analyses were carried out on the samples, and the correlation of these data with the magnetic properties. Results of this study show the possibility of using magnetic field annealing as a way to increase the permeability of a material with high carbon content as the nodular cast iron. Show more

Keywords: Magnetic field, annealing, nodular cast iron, speaker cores

DOI: 10.3233/JAE-2011-1395

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 37, no. 1, pp. 51-65, 2011

Authors: Ajoudanian, Mohammad | Jiang, Zhongwei | Morita, Minoru

Article Type: Research Article

Abstract: This paper presents the fundamental study on design of a novel micro stirrer for high effective dissolution of cerebral thrombus or blood clot. The actuator is a beam with supported one side and the other side is free. The longitudinal waves excited by a transducer from support side, travel through a beam and before reaching the tip of beam partially impinge to a slant surface. So that some of the energy of the incident longitudinal waves are reflected …with different orientations from the length direction. The other energy would be converted to shear waves. Despite the elongation and bending at tip, there is no significant bending across other part of beam. The micro stirrer was evaluated by vertical tip displacement in varied mode shape with using FEM analysis. The obtained results demonstrated that the vertical motion of the stirrer at desired mode shape was less influenced by the length of actuator. Due to the attenuation of wave amplitude, a driving technique method is proposed to generate high-amplitude. Show more

Keywords: Piezoactuator, catheter, longitudinal wave, tip deflection

DOI: 10.3233/JAE-2011-1396

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 37, no. 1, pp. 67-77, 2011