International Journal of Applied Electromagnetics and Mechanics - Volume 30, issue 1-2

Authors: Boukhtache, S. | Azoui, B. | Féliachi, M.

Article Type: Research Article

Abstract: To characterize magnetic materials it is very important to take into account the initial magnetization curve and the magnetic hysteresis loop. Several approaches have been used to model these characteristics. However, some problems related to the accuracy of the results, especially at the knee of the curves have been encountered. This paper presents a contribution to solve this problem using both a simulated annealing algorithm to optimize the parameters of the Jiles-Atherton magnetic hysteresis model and …the Brillouin theory to express the anhysteritic magnetization. The obtained results are in good agreement with measurements performed on silicon- iron sheets. Show more

Keywords: Langevin function, Brillouin function, hysteresis, optimization, simulated annealing algorithm

DOI: 10.3233/JAE-2009-1012

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 1-7, 2009

Authors: Sun, Rensheng | Kempel, Leo C. | Zong, Liming | Hawley, Martin C. | Benard, Andre

Article Type: Research Article

Abstract: This paper presents a self-consistent 3D marching-in-time multiphysics model, which includes electromagnetic field distribution, microwave power absorption, heat transfer, and polymer curing kinetics. Temperature- and cure-dependent permittivity and curing kinetics for DGEBA/DDS based on experimental data are explicitly included in the model. An edge-based finite element method (FEM) is implemented for the electromagnetic model, whereas node-based FEM is used in the heat transfer model. The numerical results can be used to determine …the time-dependent temperature distribution and curing profile across the polymer sample, as well as the electromagnetic field distribution within the cavity applicator. The numerical results are compared with the measured data and a good agreement is achieved. Show more

Keywords: Multiphysics modeling, finite element method (FEM), temperature- and cure-dependent permittivity, microwave thermoset curing

DOI: 10.3233/JAE-2009-1033

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 9-28, 2009

Authors: Zhang, Dongli | Chen, Zhenmao | Xu, Minglong | Lu, Tian-jian

Article Type: Research Article

Abstract: The feasibility of Eddy Current Testing (ECT) for the nondestructive evaluation of cellular metallic materials is investigated. The inspection target is focused on the welding joints connecting the surface and inner layers of a typical cellular material – metallic sandwich plate. Through numerical simulations, it is found that the defects in the welding zone cause ECT signals of significant different phase property with those caused by welding bead. The multi-frequency signal processing algorithm (MFA) is used …to process the signals in order to improve the S/N ratio, which enables the recognition of crack indication from the mixed signals of welding joint. In addition, through profile reconstruction of a crack in the welding zone by means of a deterministic inverse analysis and MFA, it is demonstrated that ECT is a suitable quantitative NDE technique for the matrix sandwich material. Show more

Keywords: Cellular metallic materials, eddy current testing, welding zone cracks, multi-frequency algorithm, inverse analysis

DOI: 10.3233/JAE-2009-1034

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 29-38, 2009

Authors: Abo-Seida, Osama M. | Bishay, Samira T. | El-Morabie, Khaled M.

Article Type: Research Article

Abstract: This paper is concerned with a theoretical solution to the problem of TE-Scattering radio waves by a buried object in a three-layered medium. The region of interest consists of three homogenous layered medium, the object of an inhomogeneous material with respect to its layer. With the aid of geometrical optics technique, this paper analyzes the influence of the buried object on the scattered magnetic field from the layered medium. Closed-form expressions for the far-field of a …VMD, located above the ground surface, are obtained due to the buried object under the ground. This technique takes into consideration all the probabilities of plane waves under and above the ground to calculate the total reflection coefficient. The extra-scattered field due to the perturbation in the earth magnetic field has been obtained by solving Sommerfeld integrals (SI). The solution of SI has been based on the stationary-phase point method. The obtained results are compared with those mentioned in three- layered free buried objects. Show more

DOI: 10.3233/JAE-2009-1035

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 39-49, 2009

Authors: Jahanghir, Tavakkoli

Article Type: Research Article

Abstract: In the scientific literature, a great deal of attention is paid to building the mathematical models of electromagnetic fields in composite materials in a homogeneous environment which contains a large number of small heterogeneities of different shapes and material compositions [1]. Such models are reduced to solving boundary value problems for differential equations Maxwell with special kinds of particular boundary conditions on the structures of composite materials. In this context one of the important structures is the …spatial screen and environment which is to simulate the actual boundary conditions pairing them [2-6]. Such models provide a mathematical foundation for solving problems of electromagnetic-field shielding composite screens, that are used to solve problems of electromagnetic compatibility of technical equipment in radio and electronics. Show more

Keywords: Mathematical modeling, maxwell equations, electromagnetic fields, composite materials, chiral media, bi-isotropic media, boundary conditions, boundary problems

DOI: 10.3233/JAE-2009-1036

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 51-59, 2009

Authors: Xu, Lizhong | Liu, Xin

Article Type: Research Article

Abstract: In this paper, the magnetic linkage equations for the toroidal worm coils are deduced. The voltage balance equation of the coils and the equation of the electromagnetic torque for the drive system are presented. The system equations of the drive system are given as well. The changes of the coil inductance along with the planet position angle for the drive system are investigated, the response of the current to exciting voltage is analyzed, and the influence …of the system parameters on the start torque and the stable torque is discussed. The research is useful for design and optimum of the drive system. Show more

Keywords: Toroidal drive, electromechanical integration, electric system, dynamic analysis

DOI: 10.3233/JAE-2009-1037

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 61-82, 2009

Authors: Kiyoumarsi, Arash | Zadeh, Mohammad Reza Hassan

Article Type: Research Article

Abstract: In this paper three different rotor eccentricities, i.e., static, dynamic and a combination of them, in the rotor of rotating electrical machines are studied by considering a relative permeance function in which variations of the airgap length have been included. The airgap flux density distribution that involves the effects of rotor eccentricity is calculated using the new relative permeance function. In this study, the cylindrical rotor shape is considered. The comparison of the results of this …analytical method with which obtained by transient finite element method will also be considered in future studies. Show more

DOI: 10.3233/JAE-2009-1038

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 83-93, 2009

Authors: Junwu, Kan | Jinhao, Qiu | Kehong, Tang | Kongjun, Zhu | Chenghui, Shao

Article Type: Research Article

Abstract: The energy conversion efficiency (ECE) of a piezoelectric generator can be denoted by its effective electromechanical coupling coefficient (EECC), which depends only on the geometry parameters with a certain boundary conditions. To obtain the optimal energy-harvesting device, the Raleigh Method was utilized to establish the analysis model of circular piezoelectric composite diaphragms. Simply supported and clamped boundary conditions were considered. The relationships between the performance parameters (EECC and natural frequency) and the …structural parameters (diametric ratio β and thickness ratio α) of piezoelectric composite diaphragms were figured out. Given the correlative material parameters and boundary conditions, the performance parameters with the structural parameters as variables can be worked out. The simulation results show that the optimal structural parameters of a composite diaphragm in the case of the simply supported and clamped boundary conditions are different. A simply supported diaphragm generator tends to achieve higher effective electromechanical coupling coefficient and lower natural frequency, and is more suitable for the applications of energy harvesting. Show more

Keywords: Piezoelectric, energy harvesting, effective electromechanical coupling coefficient, energy conversion efficiency, Rayleigh method

DOI: 10.3233/JAE-2009-1039

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 95-106, 2009

Authors: Zheng, S.J. | Dai, F. | Song, Z.

Article Type: Research Article

Abstract: An attempt on the static and dynamic control of functionally graded material (FGM) shells subjected to temperature gradient is carried out by using integrated piezoelectric sensor/actuator layers. Based on the assumed natural strain and enhanced assumed strain method, an EAS piezoelectric solid shell element is developed. The effects of constituent volume fraction and feedback control gain on the static and dynamic responses of the FGM shell system are demonstrated in detail.

Keywords: Piezoelectric, solid shell element, EAS, FGM shell

DOI: 10.3233/JAE-2009-1040

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 30, no. 1-2, pp. 107-124, 2009