International Journal of Applied Electromagnetics and Mechanics - Volume 43, issue 4

Authors: Vučković, Ana N. | Raičević, Nebojša B. | Ilić, Saša S. | Aleksić, Slavoljub R.

Article Type: Research Article

Abstract: Calculation of the interaction magnetic force between two ring permanent magnets with radial magnetization is presented in the paper. Such configuration corresponds to a radial passive magnetic bearing. The simple and fast analytical approach is used for this calculation based on magnetization charges and discretization technique. The results for interaction magnetic force obtained using proposed approach are compared with finite element method (FEM). The advantage of presented approach is its simplicity and time …efficiency since only complete elliptic integrals of the second kind are used and other additional integrations are avoided in this calculation. Show more

Keywords: Permanent magnet, interaction magnetic force, finite element method (FEM), magnetization charges, rapid calculation

DOI: 10.3233/JAE-131703

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 311-323, 2013

Authors: Li, Junfeng | Harada, Hiroyuki

Article Type: Research Article

Abstract: The purpose of this study is to develop a complete mathematical model of a thick shape memory alloys (SMA) actuator based on the Liang and Rogers model. Due to hysteresis and significant nonlinearities in the behavior of shape memory alloy actuators, the modeling of SMA actuators has been a great challenge in recent years, which limit the application of these actuators. In this paper, a new model is used to represent the major and minor hysteresis …loops of SMA actuator based on the Liang and Rogers model. The modified Liang and Rogers model of SMA wire actuated by an electric current is derived and several experiments are used to validate the model and to identify the parameters. A key feature of the proposed model is to predict the martensite starting temperature of minor loops. This model can be used to develop a position control system for the SMA actuator. Simulation results for the model are found to be in good agreement with experimental data. Show more

Keywords: SMA actuator, major and minor hysteresis loops, modeling

DOI: 10.3233/JAE-131704

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 325-335, 2013

Authors: Belli, Zoubida | Mekideche, Mohamed Rachid

Article Type: Research Article

Abstract: The aim of this study is to analyze and investigate some techniques to reduce eddy current losses in permanent magnets. First, a model using Maxwell's equations to analyze eddy current in permanent magnets is presented. Second, the effect of magnet circumferential segmentation on the eddy current losses in case of a surface mounted permanent magnets synchronous machine is investigated. A simple analysis of magnet demagnetization due to its eddy current losses is also studied. In a …third step, second technique for reducing eddy current losses is presented. It relates to the stator slots skew, where the best skewing angle is obtained by means of an optimization process using genetic algorithm. A 2D nonlinear finite elements code is developed to achieve the purposes of the presented work. Show more

Keywords: Permanent magnet, eddy current analysis, dynamic losses reduction, finite elements magnetic field computation, magnet segmentation, magnet demagnetization, stator slots skew, genetic algorithm

DOI: 10.3233/JAE-131720

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 337-346, 2013

Authors: Yang, Fuqian

Article Type: Research Article

Abstract: The contact behavior between a transversely isotropic piezoelectric material and a rigid-conducting punch of flat-end was analyzed under the condition that there is no biased-electric potential applied to the punch. Two limiting cases were studied; one was for semi-infinite piezoelectric materials and the other for piezoelectric films with contact radius much larger than the film thickness. Analytical relationships were derived between the indentation load and the indentation depth and between the indentation-induced potential …and the indentation depth. Both the indentation load and the indentation-induced potential are proportional to the indentation depth. For the adhesive contact, the pull-off force is proportional to the 3/2 power of the punch radius for semi-infinite piezoelectric materials and to the square of the punch radius for piezoelectric films. The piezoelectric charge coefficient determined from the contact deformation of a piezoelectric film with contact radius much larger than the film thickness is only dependent on dielectric constant and piezoelectric constant. Show more

Keywords: Contact, piezoelectric materials, adhesion

DOI: 10.3233/JAE-131721

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 347-352, 2013

Authors: Sun, Tongsheng

Article Type: Research Article

Abstract: In order to improve recycling quality of asphalt mixtures based on microwave heating, thermoelectric coupling theory is researched. Heat conduction equation is built according to Fourier's Law. Series model, parallel model and Maxwell model are studied to solve thermal conductivity of asphalt mixtures. Radiation field model of pyramidal horn antenna is set up and mean value of electric field intensity is measured by experiment. Thermoelectric coupling model is built on the basis of dielectric property …of asphalt mixtures. Numerical simulation is performed for the model. It is found that influence of asphalt-aggregate ratio on temperature field is not distinct. Average temperature of asphalt mixtures is related to microwave power and increases with microwave power linearly. The asphalt mixtures using diorite as aggregate have a strongest adsorption capability to energy. The result can simulate hot in-place regeneration process, and has important significance to improve regeneration quality of asphalt mixtures. Show more

Keywords: Asphalt mixtures, microwave heating, thermoelectric coupling, thermal conductivity, temperature field

DOI: 10.3233/JAE-131722

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 353-363, 2013

Authors: Parvez Iqbal, A.K.M. | Aris, Ishak | Norhisam, M.

Article Type: Research Article

Abstract: Mostly in industrial spray applications pneumatic systems are utilized for operating the automatic spray gun. Linear motor can be one of the alternatives for triggering the spray gun instead of pneumatic systems due to its accuracy in valve positioning according to the required flow rate. From this point of view a tubular linear permanent magnet motor has been designed using Permeance Analysis Method (PAM) and developed. Three permeance models have been developed for PAM analysis. Among …these three models, only one model is selected as a PAM model which can be produced the required amount of thrust for triggering the spray gun. After selecting the PAM thrust model, the size of the motor has been optimized by analyzing the effect of thrust constant, electrical and mechanical time constant. Finally based on the optimized data, the motor has been fabricated and tested that shows the good argument with the analysis result. Show more

Keywords: Linear motor, thrust constant, electrical time constant, mechanical time constant

DOI: 10.3233/JAE-131723

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 365-378, 2013

Authors: Shah, Nayyar Abbas | Ahmad, Faiz | Syed, Aqeel A. | Naqvi, Qaisar A.

Article Type: Research Article

Abstract: Behavior of different planar multilayer periodic structures due to plane wave excitation has been studied using the transfer matrix method. Multilayer structure is composed of odd number of slabs and the layers at odd locations have same characteristics and layers at even locations have same characteristics. For each structure, layers at odd locations are of chiral nihility metamaterial whereas three different cases are considered for layers at even locations, i.e., dielectric, chiral and chiral nihility. Effects …of polarization rotation due to the optical activity of material's chirality is studied with respect angle of incidence and frequency in THz region. Chiral nihility adds property of transparency to the structure for normal incidence. Chiral nihility-chiral nihility structure for normal incidence yields transparency whereas same structure for oblique incidence yields total rejection at higher frequencies. Show more

Keywords: Chiral and chiral nihility metamaterials, transfer matrix method, electromagnetic mirror, polarization rotator

DOI: 10.3233/JAE-131724

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 379-387, 2013

Authors: Wang, Chun'e | Fang, Jiancheng | Tang, Jiqiang | Sun, Jinji

Article Type: Research Article

Abstract: This paper deals with the novel structure and coupling analysis of a 3-degrees of freedom (3-DOF) conical magnetic bearing. The conical stators of the bearing are designed symmetrical to provide the axial control exclusively, and the radial stators are separated by nonmagnetic material between X and Y channels, so the magnetic flux path can be separated among different channels. The configuration and working principle of the bearing are provided, and the mathematical model is derived based …on the bias and control magnetic circuits. In order to evaluate the degree of force coupling between different channels, the concept of coupling factor is proposed, which is defined as the ratio of force variation caused by coupling to the original force when there is no coupling. The coupling factors are analyzed not only among the translational movement of X, Y and Z channels but also between the translational and rotational degrees of freedom. The calculation results show that although the component coupling factors of each magnetic poles are a little larger, the resultant ones in X, Y and Z directions of the designed bearing are all less than 4%. Therefore, the magnetic forces and torques of different channels are weakly coupled, and it is convenient for the control of the magnetic bearing. Show more

Keywords: Conical magnetic bearing, magnetic force coupling, coupling factor, equivalent magnetic circuit

DOI: 10.3233/JAE-131725

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 389-401, 2013

Authors: Rani, Shweta | Singh, A.P.

Article Type: Research Article

Abstract: An optimized design of printed hybrid fractal tree (PHFT) antenna based on binary fractal tree geometry is presented and discussed. In this paper miniaturization has been achieved by inserting a modified Koch curve in the conventional fractal binary tree. A comparative study shows that the new antenna provides 6.87% increase in radiation efficiency and 2.57% increase in antenna efficiency than conventional fractal tree antenna designed with similar dimensions. The geometrical descriptors of the proposed antenna have …been synthesized using Bacterial Foraging Optimization (BFO) and Particle Swarm Optimization (PSO) for optimizing the values of electrical parameters within specifications. A performance comparison have also been done for both of these computational techniques which reveals that BFO gives better results in terms of accuracy than PSO for required working frequencies (5.2 GHz and 10.6 GHz). Representative results of optimized PHFT antenna for both simulations and experimental validations are reported in order to access the effectiveness of the developed approach for reliable implementation in wireless telemedicine applications. Show more

Keywords: Fractal tree antenna, hybrid fractals, BFO, PSO

DOI: 10.3233/JAE-131729

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 403-415, 2013

Article Type: Other

Abstract: Author Index Volume 43 (2013)

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 43, no. 4, pp. 417-420, 2013