| 1. |
- Bergqvist, A., et al.
(author)
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A stress-dependent magnetic Preisach hysteresis model
- 1991
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In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 27, s. 4796-4798
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Journal article (peer-reviewed)abstract
- The authors present a generalization of the classical Preisach model which handles coupled magnetic and mechanical hysteresis. Magnetostrictive materials are known to have hysteresis with respect to both magnetic field H and mechanical stress lambda;. To test the validity of the model, experiments where the two components H and lambda; have been verified in many different ways have been performed on Terfenol-D and compared to results computed from the model. Some of these results are presented. This stress-dependent model is found to have an accuracy comparable to that of the classical Preisach model
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| 2. |
- Jansson, Magnus, et al.
(author)
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Efficient Implementation of a Submodel for Composite Materials to be Combined with the FDTD-Algorithm
- 1994
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In: IEEE Transactions on Magnetics. - : IEEE Magnetics Society. - 0018-9464 .- 1941-0069. ; 30:5, s. 3188-3191
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Journal article (peer-reviewed)abstract
- A submodel to be used for thin sheets of semiconducting materials in combination with the finite difference time domain algorithm for solving Maxwell's equations is derived. Emphasis is concentrated on accomplishing an efficient and robust algorithm. Stability properties of the combined model are also investigated
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| 3. |
- Kvarnsjo, L., et al.
(author)
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A method of measuring eddy current impedances in giant magnetostrictive materials
- 1990
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In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 26, s. 2574-2576
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Journal article (peer-reviewed)abstract
- A method of calculating eddy-current impedances for giant magnetostrictive materials during dynamic magnetization is suggested. The method is based on solving the power-balance equation for each time step of the recorded data. The experimentally obtained impedances can be used for accurately modeling the magnetostrictive process
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| 4. |
- Kvarnsjo, L., et al.
(author)
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Application of a stress-dependent magnetic Preisach hysteresis model on a simulation model for Terfenol-D
- 1992
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In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 28, s. 2623-2625
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Journal article (peer-reviewed)abstract
- A previously reported simulation model for the highly magnetorestrictive material. Terfenol-D has been extended by implementation of the recently developed stress-dependent magnetic Preisach hysteresis model. The model is based on static measurements of material characteristics combined with equations for the dynamic mechanical and magnetic behavior of the material. As a test of the model the authors have simulated the behavior of a Terfenol-D rod for different load conditions. The results show that the model is able to describe the influence of nonlinearities, eddy currents, and hysteresis on the magnetomechanical transduction process of magnetorestrictive materials
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| 5. |
- Kvarnsjo, L., et al.
(author)
-
Nonlinear 2-D transient modeling of Terfenol-D rods
- 1991
-
In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 27, s. 5349-5351
-
Journal article (peer-reviewed)abstract
- A nonlinear model for simulation of the transient behavior of magnetostrictive Terfenol-D rods has been developed. The model is based on static characterization of the magnetic and mechanical properties of the rods combined with Maxwell’s equations and classical mechanic laws. Registrations for different rods are stored in a database which is called upon by the model. The model is able to handle longitudinal wave propagation and eddy current influence under transient conditions. Any combination from the set of magnetic field (current), magnetic flux density (voltage), mechanical motion, mechanical stress, and mechanical impedance can be used as the two independent variables in the model. This modeling technique implies that the experimental set-up used for data acquisition of the material properties should be regarded as a part of the modeling process. The experimental set-up used for the characterization of Terfenol-D properties can produce magnetic fields and mechanical stresses independently of each other and of arbitrary shape. A specially designed sample holder provides a homogeneous magnetic field and mechanical stress field inside the rod
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| 6. |
- Lundgren, A., et al.
(author)
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A magnetostrictive electric generator
- 1993
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In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 29, s. 3150-3152
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Journal article (peer-reviewed)abstract
- An electric generator based on the magnetostrictive effect is presented. Longitudinal oscillations of a Terfenol-D rod give rise to a varying flux which induces a current in a coil wound around the rod. A small prototype of such a device is discussed, and both calculations and experiments are performed. The problem of eddy current losses is addressed
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| 7. |
- Tiberg, H., et al.
(author)
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A method of computing electro-mechanical transfer functions for magnetostrictive functional units
- 1992
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In: IEEE transactions on magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464 .- 1941-0069. ; 28, s. 2808-2810
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Journal article (peer-reviewed)abstract
- Transfer functions of a magnetostrictive functional unit are presented. The functional unit consists of a Terfenol-D rod with a magnetizing coil and a closed magnetic circuit. The rod is modeled by a previously presented simulation model for Terfenol-D rods. In a mathematical formulation of the electromechanical coupling the quality of the magnetic circuit is taken into account when computing transfer functions of the functional unit. Numerical results are presented
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| 8. |
- Johansson, Christer, et al.
(author)
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Influence of sample geometry in a vibrating sample magnetometer
- 1994
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In: IEEE Transactions on Magnetics. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9464. ; 30, s. 1064-1066
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Journal article (peer-reviewed)abstract
- We have investigated the influence of sample size on the calibration of a vibrating sample magnetometer. As expected, when measurements and calibration are carried out on samples with the same shape the results agree within the experimental uncertainty. For two cylindrical samples of nickel, one with length and diameter 2.0 and 2.0 mm, and another with 5.3 and 1.0 mm respectively, the magnetometer signal varies with the length, in good agreement with numerical calculations.
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