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# IEEE Transactions on Magnetics

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Displaying Results 1 - 25 of 202
• ### Nonlinear 3D magnetostatic field calculation by the integral equation method with surface and volume magnetic charges

Publication Year: 1992, Page(s):1088 - 1091
Cited by:  Papers (22)  |  Patents (1)
| | PDF (268 KB)

The authors present a mathematical model for the 3-D nonlinear magnetostatic field based on integral equations with fictitious surface and volume magnetic charges. The solution is performed by the extended boundary element method including surface elements and volume elements. Examples of calculation for both linear and nonlinear magnetic systems are presented. The method has been shown to be accu... View full abstract»

• ### Hybrid FEM-BIM formulation using electric and magnetic variables

Publication Year: 1992, Page(s):1647 - 1650
Cited by:  Papers (3)
| | PDF (376 KB)

A hybrid finite-element-boundary-integral method using a mixed electric-magnetic formulation for 3-D eddy current computation is presented. The finite element formulation using tetrahedral edge elements in terms of electric field is employed in the conducting region. The boundary integral method in terms of magnetic field is used in the air space. The use of a vector variable in the air space toge... View full abstract»

• ### The mixed finite element method for analysis of nonlinear time dependent eddy current field

Publication Year: 1992, Page(s):1201 - 1203
| | PDF (148 KB)

The mixed finite element method for a type of nonlinear parabolic equation arising from the nonlinear time-dependent eddy current field is discussed. Offering completely discretized schemes, applied to calculations of eddy current field in transformers under overexciting conditions, this method has been proved to have some eminent advantages, with simpler calculation of formulas, higher accuracy, ... View full abstract»

• ### Expansion of periodic boundary condition for 3-D FEM analysis using edge elements

Publication Year: 1992, Page(s):1084 - 1087
Cited by:  Papers (3)
| | PDF (304 KB)

The application of periodic boundary conditions in the analysis of three-dimensional magnetic fields by finite element methods (FEMs) leads to a substantial reduction of computation labor and storage. The expansion of the condition for magnetostatic curl-curl formulation with the magnetic vector potential employing edge tetrahedral elements is discussed. Differences between the definitions of the ... View full abstract»

• ### The impedance boundary condition applied to the finite element method using the magnetic vector potential as state variable: a rigorous solution for high frequency axisymmetric problems

Publication Year: 1992, Page(s):1643 - 1646
Cited by:  Papers (7)
| | PDF (268 KB)

The use of the impedance boundary condition in a finite element formulation is presented for high-frequency axisymmetric problems. The method has the following advantages: (a) a gain in discretization time; (b) a smaller system to be solved and thus a gain in computer memory; and (c) a gain in total computation time View full abstract»

• ### Modified surface impedance boundary condition applied to eddy current problems

Publication Year: 1992, Page(s):1197 - 1200
Cited by:  Papers (10)
| | PDF (292 KB)

The authors describe the use of a modified surface impedance boundary condition (IBC) for solving eddy current problems. An approximate expression for the surface impedance at sharp edges of any angle has been derived for TM conduction problems. The validity of the expression is tested by using the method of fundamental solutions (MFS) to solve selected problems with the use of IBC and in the full... View full abstract»

• ### The influence of finite element discretisation on the prediction of cogging torque in permanent magnet excited motors

Publication Year: 1992, Page(s):1080 - 1083
Cited by:  Papers (54)
| | PDF (344 KB)

The accuracy of the predicted torque from a finite-element calculation is determined largely by the level of discretization, as well as the evaluation method employed. The stored energy is used to gauge the adequacy of the meshing density in a finite element model for the prediction of the cogging torque in permanent magnet excited motors. The relationship between the stored energy and the torque ... View full abstract»

• ### A volume integral formulation for nonlinear magnetostatics and eddy currents using edge elements

Publication Year: 1992, Page(s):1639 - 1642
Cited by:  Papers (20)
| | PDF (312 KB)

The properties of Whitney elements provide the basis of a novel integral formulation for solving three-dimensional magnetostatics and eddy-current problems. Using a tree structure reduces the number of unknowns to a few less than the number of nodes for the static case, a significant saving over earlier integral formulations. Interface conditions are satisfied exactly, but the material constitutiv... View full abstract»

• ### An approach to the solution of three-dimensional voltage driven and multiply connected eddy current problems

Publication Year: 1992, Page(s):1193 - 1196
Cited by:  Papers (21)
| | PDF (252 KB)

The authors describe a method for voltage-driven problems which may contain conducting regions in which eddy currents would be induced. These regions may be multiply connected. The method uses a single reduced scalar potential coupled with the magnetic field vector in conducting regions. The approach is verified by solving the jumping ring' and bath plate' problems View full abstract»

• ### A new scalar potential formulation for 3-D magnetostatics necessitating no source field calculation

Publication Year: 1992, Page(s):1103 - 1106
Cited by:  Papers (32)
| | PDF (308 KB)

The authors present a new scalar potential formulation for 3-D magnetostatic field analysis. The method is based on a convenient partition of the magnetic field that permits representation of multiply connected multifilamentary conductors by means of a fictitious field with known distribution. This technique permits the efficient modeling of laminated iron cores with or without air gaps and needs ... View full abstract»

• ### Optimizing electromagnetic devices combining direct search methods with simulated annealing

Publication Year: 1992, Page(s):1545 - 1548
Cited by:  Papers (50)  |  Patents (1)
| | PDF (384 KB)

Problems of optimization in computational electromagnetics are discussed with particular reference to the determination of the global minimum of practical objective functions. An optimizing environment is described which uses integral methods for calculating user-defined objective functions. Results are presented which combine stochastic and direct search techniques to find a satisfactory design o... View full abstract»

• ### The use of image charges in the charge-simulation method: a parallel-plane dielectric plate covering a conductor

Publication Year: 1992, Page(s):1076 - 1079
Cited by:  Papers (2)
| | PDF (320 KB)

It is noted that, when applied to two dielectrics, the charge simulation method needs a number of additional charges with respect to the single dielectric case. This can strongly increase the time of computation. It is analytically shown that, if the geometry to be solved is a dielectric medium facing a parallel plane dielectric plate covering a conductor, the problem can be again treated with the... View full abstract»

• ### Refinement strategies in adaptive meshing

Publication Year: 1992, Page(s):1739 - 1742
Cited by:  Papers (11)
| | PDF (252 KB)

Two strategies for reducing the overall number of finite-element computations needed in an adaptive meshing algorithm are proposed. In the first strategy (called two-threshold refinement), numerical values of the estimated local error are used both to select the elements to be refined and to decide into how may new elements each of them will be subdivided. In the second strategy (called refinement... View full abstract»

• ### A user oriented shell for electromagnetic CAD of axisymmetric devices

Publication Year: 1992, Page(s):1782 - 1784
Cited by:  Papers (2)
| | PDF (216 KB)

A special shell for a general-purpose FEM (finite element method) package (MagNet) for the electromagnetic CAD (computer-aided design) of axisymmetric devices is presented. The basic idea of the shell is that a script file may be quickly and easily created for every basic design. Then, the whole FEM solution procedure is conducted automatically. Any design changes can be made easily and quickly, a... View full abstract»

• ### Angular variation of coercivity in thin-film media by micromagnetic model

Publication Year: 1992, Page(s):986 - 989
Cited by:  Papers (10)
| | PDF (324 KB)

A computer micromagnetic simulation model is employed to study the angular variation of coercivity (out of plane) in thin-film media. Each grain of the film is uniformly magnetized and switches coherently according to the S-W model. The M-H hysteresis loops for applied fields at different angles to the film plane are obtained for various magnetostatic interaction parameters, quan... View full abstract»

• ### The modelling of segmented laminations in three dimensional eddy current calculations

Publication Year: 1992, Page(s):1122 - 1125
Cited by:  Papers (12)
| | PDF (412 KB)

A formulation is presented for the inclusion of segmentation effects in a three-dimensional eddy current model of large laminated iron cores. The model has been developed for the study of eddy currents induced in the end laminations of turbogenerator stator cores. It includes magnetic nonlinearity and represents the overlapping pattern which occurs between successive lamination layers by introduci... View full abstract»

• ### Higher finite element derivatives for the quick synthesis of electromagnetic devices

Publication Year: 1992, Page(s):1565 - 1568
Cited by:  Papers (10)
| | PDF (284 KB)

A fast, robust scheme for synthesizing electromagnetic devices from the higher derivatives of object functions is presented. A method of computing derivatives of any given order from a finite element solution employing trial functions of any order is presented. These derivatives are used in expanding the object function in device optimization as a Taylor series. The series truncates after the eigh... View full abstract»

• ### Inverse problems with boundary elements: synthesizing a capacitor

Publication Year: 1992, Page(s):1529 - 1532
Cited by:  Papers (5)
| | PDF (300 KB)

A methodology for the solution of inverse problems in electromagnetics using boundary element analysis is developed. It is shown how the boundary element solution may be differentiated with respect to a design parameter without having to solve a second perturbed field problem. It is demonstrated that the small, full nature of the boundary element coefficient matrix makes the method cost-effective ... View full abstract»

• ### Magnetic field modelling and calculation of reflected impedance of inductive sensors

Publication Year: 1992, Page(s):1426 - 1429
Cited by:  Papers (3)
| | PDF (420 KB)

Practical aspects of finite-element modeling of magnetic fields and calculating integral parameters such as a reflected impedance in inductive sensing devices are discussed. The electromagnetics of such sensors is briefly explained, and many practical modeling techniques are put forward. Excellent agreement with experiment is reported View full abstract»

• ### A three-dimensional infinite element for modeling open-boundary field problems

Publication Year: 1992, Page(s):1675 - 1678
Cited by:  Papers (10)
| | PDF (220 KB)

A three-dimensional infinite element is considered which has four nodes and is compatible with conventional cuboids. The infinite element is being developed for exterior potential problems governed by Laplace's equation. The element is formulated in such a simple way that closed-form expressions for the element matrix are obtained. The element can easily be incorporated into existing finite elemen... View full abstract»

• ### Finite-element analysis of high-frequency axisymmetric device problems

Publication Year: 1992, Page(s):1635 - 1638
| | PDF (264 KB)

A finite-element scheme for solving wave propagation problems in devices with complete azimuthal symmetry both in their material properties and in their geometry is presented. The φ-coordinate variation is restricted to sin(nφ+ξ), thus requiring only a two-dimensional space for the complete finite-element analysis. The open radiating boundaries inherent in many propagation prob... View full abstract»

• ### Modelling of inductive effects in thin wire coils

Publication Year: 1992, Page(s):1190 - 1192
Cited by:  Papers (6)
| | PDF (180 KB)

In conducting media, inductive effects give rise to eddy currents that produce the skin effect and the proximity effect. In thin wire coils in which the inductive effects are present the current density is forced to remain constant in the coil if the skin depth is larger than the characteristic size of the wire. The authors present a homogenization technique based on the finite element method to t... View full abstract»

• ### Boundary element analysis of 3-D magnetostatic problems using scalar potentials

Publication Year: 1992, Page(s):1099 - 1102
Cited by:  Papers (12)  |  Patents (1)
| | PDF (236 KB)

A boundary element formulation for 3-D nonlinear magnetostatic field problems using the total scalar potential and its normal derivative as unknowns is described. The boundary integral equation is derived from a differential equation for the total scalar potential where a nonlinear operator term can be separated from a linear term. The nonlinear term leads to a volume integral which can be treated... View full abstract»

• ### Self adaptive mesh generation for 3-D finite element calculation

Publication Year: 1992, Page(s):1751 - 1754
Cited by:  Papers (7)
| | PDF (360 KB)

A three-dimensional, fully self-adaptive finite-element procedure is presented, based on the use of complementary variational principles. The use of the dual formulation ensures overall accuracy and provides a way of implementing localized mesh refinement. The initial problem meshing is achieved using a mesh generation technique based on the method of Delaunay tessellation. This work is an extensi... View full abstract»

• ### Domains and domain nucleation in magnetron-sputtered CoCr thin films

Publication Year: 1992, Page(s):998 - 1002
Cited by:  Papers (4)  |  Patents (1)
| | PDF (1176 KB)

The magnetic domain configurations in magnetron-sputtered CoCr thin films have been examined by Lorentz transmission electron microscopy. The thinnest (10 nm) films display in-plane 180° domain walls, while thicker (50 nm) films exhibit out-of-plane dot-type domain structures. The dot domains were observed even in films that had not yet developed a columnar morphology. Intermediate thickness f... View full abstract»

## Aims & Scope

IEEE Transactions on Magnetics publishes research in science and technology related to the basic physics and engineering of magnetism, magnetic materials, applied magnetics, magnetic devices, and magnetic data storage.

Full Aims & Scope

## Meet Our Editors

Editor-in-Chief
Pavel Kabos
National Institute of Standards and Technology