An overview on nucleation theories and models

Campos, Marcos Flávio de; Castro, José Adilson de

doi:10.1016/j.jre.2019.02.002

Cited by 13 publications

(2 citation statements)

References 59 publications

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“…There are also materials described by single-domain particles or at least partially described by single-domain particles. This is the case for small grains and particles that are too small to contain several domains [ 23 ].…”

Section: Magnetic Hysteresismentioning

confidence: 99%

Review of Play and Preisach Models for Hysteresis in Magnetic Materials

Mörée

Leijon

2023

Materials

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This paper studies the properties of the Preisach model and the play model, and compare their similarities. Both are history-dependent hysteresis models that are used to model magnetic hysteresis. They are described as discrete sums of simple hysteresis operators but can easily be reformulated as integral equations of continuous distribution functions using either a Preisach weight distribution function or a play distribution function. The models are mostly seen as phenomenological or mathematical tools but can also be related to friction-like pinning of domain-wall motions, where Rayleigh’s law of magnetic hysteresis can be seen as the simplest case on either the play model or the Preisach model. They are poor at modeling other domain behavior, such as nucleation-driven hysteresis. Yet another hysteresis model is the stop model, which can be seen as the inverted version of the play model. This type of model has advantages for expressions linked to energy and can be related to Steinmetz equation of hysteresis losses. The models share several mathematical properties, such as the congruency property and wiping-out property, and both models have a history of dependence that can be described by the series of past reversal points. More generally, it is shown that the many models can be expressed as Preisach models, showing that they can be treated as subcategories of the Preisach type models. These include the play model, the stop model and also the alternative KP-hysteron model.

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Section: Magnetic Hysteresismentioning

confidence: 99%

Review of Play and Preisach Models for Hysteresis in Magnetic Materials

Mörée

Leijon

2023

Materials

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“…Many different models have been proposed to explain the hysteresis behaviour in materials with small and large grain sizes. A large grain size means the domain wall thickness is above the single domain particle size [155].…”

Section: Advanced Mathematical Models For the Hysteresismentioning

confidence: 99%

Iron Loss Calculation Methods for Numerical Analysis of 3D-Printed Rotating Machines: A Review

Orosz,

Horváth,

Tóth

et al. 2023

Energies

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Three-dimensional printing is a promising technology that offers increased freedom to create topologically optimised electrical machine designs with a much smaller layer thickness achievable with the current, laminated steel-sheet-based technology. These composite materials have promising magnetic behaviour, which can be competitive with the current magnetic materials. Accurately calculating the iron losses is challenging due to magnetic steels’ highly nonlinear hysteretic behaviour. Many numerical methodologies have been developed and applied in FEM-based simulations from the first introduced Steinmetz formulae. However, these old curve-fitting-based iron loss models are still actively used in modern finite-element solvers due to their simplicity and high computational demand for more-accurate mathematical methods, such as Preisach- or Jiles–Atherton-model-based calculations. In the case of 3D-printed electrical machines, where the printed material can have a strongly anisotropic behaviour and it is hard to define a standardised measurement, the applicability of the curve-fitting-based iron loss methodologies is limited. The following paper proposes an overview of the current problems and solutions for iron loss calculation and measurement methodologies and discusses their applicability in designing and optimising 3D-printed electrical machines.

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