scholarly journals A constraint-based optimization technique for estimating physical parameters of Jiles – Atherton hysteresis model

2020 ◽  
Vol 39 (6) ◽  
pp. 1281-1298
Author(s):  
Brijesh Upadhaya ◽  
Paavo Rasilo ◽  
Lauri Perkkiö ◽  
Paul Handgruber ◽  
Anouar Belahcen ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Optimization Algorithms ◽  
Hysteresis Loops ◽  
Logistic Function ◽  
Silicon Steel ◽  
Physical Parameters ◽  
Hysteresis Model ◽  
Physical Constraint ◽  
Content Type ◽  
Parameter Fitting

Purpose Improperly fitted parameters for the Jiles–Atherton (JA) hysteresis model can lead to non-physical hysteresis loops when ferromagnetic materials are simulated. This can be remedied by including a proper physical constraint in the parameter-fitting optimization algorithm. This paper aims to implement the constraint in the meta-heuristic simulated annealing (SA) optimization and Nelder–Mead simplex (NMS) algorithms to find JA model parameters that yield a physical hysteresis loop. The quasi-static B(H)-characteristics of a non-oriented (NO) silicon steel sheet are simulated, using existing measurements from a single sheet tester. Hysteresis loops received from the JA model under modified logistic function and piecewise cubic spline fitted to the average M(H) curve are compared against the measured minor and major hysteresis loops. Design/methodology/approach A physical constraint takes into account the anhysteretic susceptibility at the origin. This helps in the optimization decision-making, whether to accept or reject randomly generated parameters at a given iteration step. A combination of global and local heuristic optimization methods is used to determine the parameters of the JA hysteresis model. First, the SA method is applied and after that the NMS method is used in the process. Findings The implementation of a physical constraint improves the robustness of the parameter fitting and leads to more physical hysteresis loops. Modeling the anhysteretic magnetization by a spline fitted to the average of a measured major hysteresis loop provides a significantly better fit with the data than using analytical functions for the purpose. The results show that a modified logistic function can be considered a suitable anhysteretic (analytical) function for the NO silicon steel used in this paper. At high magnitude excitations, the average M(H) curve yields the proper fitting with the measured hysteresis loop. However, the parameters valid for the major hysteresis loop do not produce proper fitting for minor hysteresis loops. Originality/value The physical constraint is added in the SA and NMS optimization algorithms. The optimization algorithms are taken from the GNU Scientific Library, which is available from the GNU project. The methods described in this paper can be applied to estimate the physical parameters of the JA hysteresis model, particularly for the unidirectional alternating B(H) characteristics of NO silicon steel.

A polycrystal hysteresis model for ferroelectric ceramics

2006 ◽  
Vol 462 (2069) ◽  
pp. 1573-1592 ◽  
Author(s):  
Y Su ◽  
G.J Weng
Keyword(s):  
Electric Field ◽  
Hysteresis Loop ◽  
Ferroelectric Properties ◽  
Electric Displacement ◽  
Hysteresis Loops ◽  
Ferroelectric Ceramics ◽  
Domain Growth ◽  
Thermodynamic Approach ◽  
Hysteresis Model ◽  
Self Consistent

Most key elements of ferroelectric properties are defined through the hysteresis loops. For a ferroelectric ceramic, its loop is contributed collectively by its constituent grains, each having its own hysteresis loop when the ceramic polycrystal is under a cyclic electric field. In this paper, we propose a polycrystal hysteresis model so that the hysteresis loop of a ceramic can be calculated from the loops of its constituent grains. In this model a micromechanics-based thermodynamic approach is developed to determine the hysteresis behaviour of the constituent grains, and a self-consistent scheme is introduced to translate these behaviours to the polycrystal level. This theory differs from the classical phenomenological ones in that it is a micromechanics-based thermodynamic approach and it can provide the evolution of new domain concentration among the constituent grains. It also differs from some recent micromechanics studies in its secant form of self-consistent formulation and in its application of irreversible thermodynamics to derive the kinetic equation of domain growth. To put this two-level micromechanics theory in perspective, it is applied to a ceramic PLZT 8/65/35, to calculate its hysteresis loop between the electric displacement and the electric field ( D versus E ), and the butterfly-shaped longitudinal strain versus the electric field relation ( ϵ versus E ). The calculated results are found to be in good quantitative agreement with the test data. The corresponding evolution of new domain concentration c 1 and the individual hysteresis loops of several selected grains—along with those of the overall polycrystal—are also illustrated.

Comparison of static hysteresis models subject to arbitrary magnetization waveforms

2017 ◽  
Vol 36 (3) ◽  
pp. 774-790 ◽  
Author(s):  
Martin Petrun ◽  
Simon Steentjes ◽  
Kay Hameyer ◽  
Drago Dolinar
Keyword(s):  
Design Methodology ◽  
Hysteresis Loops ◽  
Magnetization Curves ◽  
Hysteresis Model ◽  
Content Type ◽  
The Individual ◽  
Practical Implications ◽  
Excitation Waveform ◽  
Arbitrary Magnetization ◽  
Selection Of

Purpose This paper aims to compare different static history-independent hysteresis models (mathematical-, behavioural- and physical-based ones) and a history-dependent hysteresis model in terms of parameter identification effort and accuracy. Design/methodology/approach The discussed models were tested for distorted-excitation waveforms to explore their predictions of complex magnetization curves. Static hysteresis models were evaluated by comparing the calculated and measured major and minor static hysteresis loops. Findings The analysis shows that the resulting accuracy of the different hysteresis models is strongly dependent on the excitation waveform, i.e. smooth excitations, distorted flux waveforms, transients or steady-state regimes. Obtained results show significant differences between predictions of discussed static hysteresis models. Research limitations/implications The general aim was to identify the models on a very basic and limited set of measured data, i.e. if possible using only the measured major static loop of the material. The quasi-static major hysteresis loop was measured at Bmax = 1.5 T. Practical/implications The presented analysis allows selection of the most-suited hysteresis model for the sought-for application and appraisal of the individual limitations. Originality/value The presented analysis shows differences in intrinsic mechanisms to predict magnetization curves of the majority of the well-known static hysteresis models. The results are essential when selecting the most-suited hysteresis model for a specific application.

Hysteresis loop reversing by applying Langevin approximation

2017 ◽  
Vol 36 (4) ◽  
pp. 850-858 ◽  
Author(s):  
Jeno Takacs
Keyword(s):  
Hysteresis Loop ◽  
Analytical Formula ◽  
Hysteresis Loops ◽  
Industrial Applications ◽  
Engineering Practice ◽  
Mathematical Tool ◽  
Content Type ◽  
Practical Applications ◽  
Langevin Function ◽  
Simple Analytical Formula

Purpose The purpose of this paper is to model one of the unsolved problems of magnetism, the reversal of hysteresis loops, in an analytical way. The mathematical models, describing the multiphase steel used in engineering practice, without any exception, are unsuited to provide a way to reverse the hysteretic process. In this paper, a proposal is put forward to model it by using analytical expressions, applying the reversal of the Langevin function. This model works with a high accuracy, giving useful answers to a long unsolved magnetic problem, the lack of reversibility of the hysteresis loop. The use of the proposal is shown by applying the reversal of Langevin function to a sinusoidal and a triangular waveform, the two most frequently used waveforms in research, test and industrial applications. Schematic representations are given for the wave reconstruction by using the proposed method. Design/methodology/approach The unsolved reversibility of the hysteresis loop is approached by a simple analytical formula, providing close approximation for most applications. Findings The proposed solution, applying the reversal of Langevin function, to the problem provides a good practical solution. Research limitations/implications The simple analytical formula has been applied to a number of loops of widely different shapes and sizes with excellent results. Practical implications The proposed solution provides a missing mathematical tool to an unsolved problem for practical applications. Social implications The solution proposed will reduce the work required and provide replacement for expensive complex test instrumentation. Originality/value To the best of the authors’ knowledge, this approach used in this study is the first successful approach in this field, irrespective of the required waveform, and is completely independent of the model used by the user.

Ground state phase diagrams and magnetic properties of the double perovskite La2NiMnO6

2019 ◽  
Vol 16 (2) ◽  
pp. 281-292
Author(s):  
Ibtissam El Housni ◽  
Samira Idrissi ◽  
Najlae El Mekkaoui ◽  
Sara Mtougui ◽  
Rajaa Khalladi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Diagrams ◽  
Crystal Field ◽  
Ground State ◽  
Exchange Coupling ◽  
Hysteresis Loops ◽  
Magnetic Behavior ◽  
Double Perovskite ◽  
Physical Parameters ◽  
Content Type

Purpose The purpose of this paper is to investigate the magnetic properties and the ground state phase diagrams of the double perovskite La2NiMnO6 using the Monte Carlo simulations (MCS). Design/methodology/approach In this work, the authors propose a Hamiltonian modeling this compound, described by an Ising model, with different exchange coupling interactions J11, J12 and J22 between the only magnetic atoms Ni and Mn. Findings Starting with the ground state phase diagrams, the authors present and discuss the stable configurations in different physical parameter planes. On the other hand, the authors present the investigation of the magnetic properties and the magnetization behaviors of the magnetic susceptibilities, as a function of temperature, crystal field, the exchange coupling interactions and the Zeeman energy. To complete this study, the authors illustrate the dependency of the total magnetizations for the hysteresis loops of the double perovskite La2NiMnO6 compound. This study is done for fixed values of temperature, the exchange coupling interactions and crystal field. Originality/value The authors modeled the different physical parameters of the double perovskite La2NiMnO with a Hamiltonian describing the system. At T=0K, the authors discussed the ground state phase diagrams of different physical parameters planes. For non-null temperature values, the authors studied the magnetic behavior of the double perovskite La2NiMnO using MCS under the metropolis algorithm. The authors expect that the results of these simulations can provide some important keys for the experimental research and technology applications of the double perovskite La2NiMnO6 in the future.

Analytical way of transforming the hyperbolic hysteresis model into the T(x) model

2018 ◽  
Vol 37 (3) ◽  
pp. 1131-1138 ◽  
Author(s):  
Jeno Takacs
Keyword(s):  
Hysteresis Loop ◽  
Magnetic Materials ◽  
Hysteresis Loops ◽  
Analytical Approximation ◽  
Hyperbolic Model ◽  
Content Type ◽  
Practical Applications ◽  
Multi Phase ◽  
Mathematical Operations ◽  
Vital Parameters

Purpose This paper aims to present an analytical way of formulating the vital parameters of an equivalent hysteresis loop of a composite, multi-component magnetic substance. By using the hyperbolic model, the only model, which separates the constituent parts of the composite magnetic materials, an equivalent loop can be composed analytically. So far, it was only possible to superimpose the tanh functions by numerical method. With this transformation, all multi-component composite substances can be treated mathematically as a single-phase material, as in the T(x) model, and include it in mathematical operations. The transformation works with good accuracy for major and minor loops and provides an easy analytical way to arrive to the vital parameters. This also shows an analytical way to the easy solution of some of the difficult problems in magnetism for multi-component ferrous materials, such as Fourier and Laplace transforms, accommodation and energy loss, already solved for the T(x) model. Design/methodology/approach The mathematical single loop formulation of hysteresis loop of a multi-phase substance shows the way in good approximation of the sum of constituent loops, described by tanh functions. That was so far only possible by numerical methods. By doing so, it becomes equivalent to the T(x) model for mathematical operations. Findings The described method gives an analytical formulation [identical to the T(x) model] of multi-component hysteresis loops described by hyperbolic model, leading to simple solution of difficult problems in magnetism such as loop reversal. Research limitations/implications Although the method is an approximation, its accuracy is good enough for use in magnetic research and practical applications in industries engaged in application of magnetic materials. Practical implications The hyperbolic model is the only one which separates the magnetic substance, used in practice, to constituent components by describing its multi-component state. Superimposing the components was only possible so far by numerical means. The transformation shown is an analytical approximation applicable in mathematical calculations. The transformation described here enables the user to apply all rules applicable to the T(x) model. Social implications This study equally helps researchers and practical users of the hyperbolic model. Originality/value This novel analytical approach to the problem provides an acceptable mathematical solution for practical problems in research and manufacturing. It shows a way to solutions of many difficult problems in magnetism.

Parameter identification of Jiles–Atherton model using the chaotic optimization method

2018 ◽  
Vol 37 (6) ◽  
pp. 2067-2080 ◽  
Author(s):  
Vesna Rubežić ◽  
Luka Lazović ◽  
Ana Jovanović
Keyword(s):  
Parameter Identification ◽  
Hysteresis Loop ◽  
Simulated Annealing Algorithm ◽  
Fitness Function ◽  
Optimization Method ◽  
Pattern Search ◽  
Simultaneous Optimization ◽  
Hysteresis Model ◽  
Suitable Alternative ◽  
Content Type

Purpose The purpose of this paper is to propose a chaotic optimization method for identifying the parameters of the Jiles–Atherton (J-A) hysteresis model. Design/methodology/approach The J-A model has five parameters which are assigned with physical meaning and whose determination is demanding. To determine these parameters, the fitness function, which represents the difference between the measured and the modeled hysteresis loop, is formed. Optimal parameter values are the values that minimize the fitness function. Findings The parameters of J-A model for three magnetic materials are determined. The model with the optimal parameters is validated using measured data and comparison with particle swarm optimization algorithm, genetic algorithm, pattern search and simulated annealing algorithm. The results show that the proposed method provides better agreement between measured and modeled hysteresis loop than other methods used for comparison. The proposed method is also suitable for simultaneous optimization of multiple hysteresis loops. Originality/value Chaotic optimization method is implemented for the first time for J-A model parameter identification. Numerical comparisons with results obtained with other optimization algorithms demonstrate that this method is a suitable alternative in parameters identification of J-A hysteresis model. Furthermore, this method is easy to implement and set up.

Exploration of activation energy and binary chemical reaction effects on nano Casson fluid flow with thermal and exponential space-based heat source

2019 ◽  
Vol 15 (1) ◽  
pp. 227-245 ◽  
Author(s):  
Gireesha B.J. ◽  
M. Archana ◽  
B. Mahanthesh ◽  
Prasannakumara B.C.
Keyword(s):  
Activation Energy ◽  
Heat Source ◽  
Chemical Reaction ◽  
Radiative Heat ◽  
Physical Parameters ◽  
Content Type ◽  
Heat Process ◽  
Flow Past ◽  
Non Linear ◽  
Exponential Space

PurposeThe purpose of this paper is to explore the effects of binary chemical reaction and activation energy on nano Casson liquid flow past a stretched plate with non-linear radiative heat, and also, the effect of a novel exponential space-dependent heat source (ESHS) aspect along with thermal-dependent heat source (THS) effect in the analysis of heat transfer in nanofluid. Comparative analysis is carried out between the flows with linear radiative heat process and non-linear radiative heat process.Design/methodology/approachA similarity transformation technique is utilised to access the ODEs from the governed PDEs. The manipulation of subsequent non-linear equations is carried out by a well-known numerical approach called Runge–Kutta–Fehlberg scheme. Obtained solutions are briefly discussed with the help of graphical and tabular illustrations.FindingsThe effects of various physical parameters on temperature, nanoparticles volume fraction and velocity fields within the boundary layer are discussed for two different flow situations, namely, flow with linear radiative heat and flow with non-linear radiative heat. It is found that an irregular heat source/sink (ESHS and THS) and non-linear solar radiation play a vital role in the enhancement of the temperature distributions.Originality/valueThe problem is relatively original to study the effects of activation energy and binary chemical reaction along with a novel exponential space-based heat source on laminar boundary flow past a stretched plate in the presence of non-linear Rosseland radiative heat.

CSF Pulse Pressure and B Waves

2005 ◽  
Vol 103 (4) ◽  
pp. 767-768 ◽  
Author(s):  
Zofia Czosnyka ◽  
Marek Czosnyka ◽  
John D. Pickard
Keyword(s):  
Pulse Pressure ◽  
Pressure Coefficient ◽  
Joint Effect ◽  
Physical Parameters ◽  
Wave Analysis ◽  
Short Term ◽  
Content Type ◽  
Pulse Pressure Method ◽  
Fine Print

Abstract Object. The appearance of numerous B waves during intracranial pressure (ICP) registration in patients with idiopathic adult hydrocephalus syndrome (IAHS) is considered to predict good outcome after shunt surgery. The aim of this study was to describe which physical parameters of the cerebrospinal fluid (CSF) system B-waves reflect and to find a method that could replace long-term B-wave analysis. Methods. Ten patients with IAHS were subjected to long-term registration of ICP and a lumbar constant-pressure infusion test. The B-wave presence, CSF outflow resistance (Rout), and relative pulse pressure coefficient (RPPC) were assessed using computerized analysis. The RPPC was introduced as a parameter reflecting the joint effect of elastance and pulsatory volume changes on ICP and was determined by relating ICP pulse amplitudes to mean ICP. Conclusions. The B-wave presence on ICP registration correlates strongly with RPPC (r = 0.91, p < 0.001, 10 patients) but not with CSF Rout. This correlation indicates that B waves—like RPPC—primarily reflect the ability of the CSF system to reallocate and store liquid rather than absorb it. The RPPC-assessing lumbar short-term CSF pulse pressure method could replace the intracranial long-term B-wave analysis.

scholarly journals CMOS Realization of All-Positive Pinched Hysteresis Loops

Complexity ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-15 ◽  
Author(s):  
B. J. Maundy ◽  
A. S. Elwakil ◽  
C. Psychalinos
Keyword(s):  
Hysteresis Loop ◽  
Detailed Analysis ◽  
Hysteresis Loops ◽  
Nonlinear Circuits ◽  
Experimental Results ◽  
First Order ◽  
Pinched Hysteresis Loop ◽  
A Charge ◽  
Pinched Hysteresis ◽  
Nmos Transistors

Two novel nonlinear circuits that exhibit an all-positive pinched hysteresis loop are proposed. These circuits employ two NMOS transistors, one of which operates in its triode region, in addition to two first-order filter sections. We show the equivalency to a charge-controlled resistance (memristance) in a decremental state via detailed analysis. Simulation and experimental results verify the proposed theory.

Exchange Bias Properties in Bulk Ni45Co5Mn38Sn12 Heusler Alloy

2014 ◽  
Vol 875-877 ◽  
pp. 272-276 ◽  
Author(s):  
Chao Jing ◽  
Ye Jun Yang ◽  
Dong Hua Yu ◽  
Zhe Li ◽  
Xiao Long Wang ◽  
...  
Keyword(s):  
Hysteresis Loop ◽  
Exchange Bias ◽  
Heusler Alloy ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Bias Field ◽  
Magnetic Hysteresis Loop ◽  
Zero Field ◽  
Co Substitution ◽  
Exchange Bias Field

We report the exchange bias properties in the bulk Ni45Co5Mn38Sn12quaternary Heusler alloy. The ferromagnetic (FM) –antiferromagnetic (AFM) interactions get reinforced after the Co substitution for Ni in the Ni-Mn-Sn alloy, which increase the exchange bias field (HE). A maximum shift in hysteresis loops of 306 Oe was observed in the 10 kOe field cooled sample. The origin of this large exchange bias field has been discussed. Magnetic hysteresis loop obtained in the zero field cooled (ZFC) mode shows double-shifted loop, and the reason of this phenomenon has been explained in detail.

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