Jiles-Atherton Model Research Articles

Influence of electrode contact arrangements on Polarisation-Electric field measurements of ferroelectric ceramics: A case study of BaTiO3

A range of partial top full bottom electrodes are used to explore the use of bi-polar Polarisation-Electric field (P–E) measurements to quantify recoverable energy (Wrec), energy loss (Wloss) and the efficiency (η) of ferroelectric BaTiO3 ceramics. The values obtained are dependent on the ratio of sample thickness (S) and top contact radius (r). With increasing S/r from 0.17 to 1.96 the P–E responses become increasingly distorted and broader. Measurements show Wrec increases by a factor of ∼ 1.4 but Wloss increases by a factor of ∼7 with η decreasing from ∼ 29% to 8%. Finite element modelling was used to simulate the experimental set-up of the sample/electrode arrangements using the Jiles-Atherton model to replicate the ferroelectric behaviour of BaTiO3. These models demonstrate the experimentally applied electric field using a simple geometric correction for sample thickness is an underestimation of the actual field experienced by the material under the top contact at high S/r values. We stress the importance of reporting the contact sizes and thicknesses of samples when using P–E measurements to assess Wrec, Wloss and η in non-linear dielectric materials. This will allow a fairer comparison of performances between various types of materials being considered for high-energy-density ceramic capacitors.

State Space Representation of Jiles-Atherton Hysteresis Model and Application for Closed-Loop Control.

Hysteresis is a fundamental characteristic of magnetic materials. The Jiles-Atherton (J-A) hysteresis model, which is known for its few parameters and clear physical interpretations, has been widely employed in simulating hysteresis characteristics. To better analyze and compute hysteresis behavior, this study established a state space representation based on the primitive J-A model. First, based on the five fundamental equations of the J-A model, a state space representation was established through variable substitution and simplification. Furthermore, to address the singularity problem at zero crossings, local linearization was obtained through an approximation method based on the actual physical properties. Based on these, the state space model was implemented using the S-function. To validate the effectiveness of the state space model, the hysteresis loops were obtained through COMSOL finite element software and tested on a permalloy toroidal sample. The particle swarm optimization (PSO) method was used for parameter identification of the state space model, and the identification results show excellent agreement with the simulation and test results. Finally, a closed-loop control system was constructed based on the state space model, and trajectory tracking experiments were conducted. The results verify the feasibility of the state space representation of the J-A model, which holds significant practical implications in the development of magnetically shielded rooms, the suppression of magnetic interference in cold atom clocks, and various other applications.

An explainable neural network integrating Jiles-Atherton and nonlinear auto-regressive exogenous models for modeling universal hysteresis

The inherent nonlinear and memory-dependent input-output characteristics of piezoelectric actuators pose challenges to the precision of piezoelectric positioning systems. In order to solve this problem, this paper firstly transforms the Jiles-Atherton (JA) model into a neural network structure, designs the Jiles-Atherton neural network (JANN), and combines JANN with nonlinear autoregressive exogenous input (NARX) neural network. A hybrid JA-NARX neural network model is proposed for the first time. This model has the advantages of simple structure, high modeling accuracy, and good interpretability. The effectiveness of the proposed JA-NARX neural network model is validated through a series of experiments, specifically assessing its capacity to accurately capture rate-dependent and asymmetric hysteresis characteristics. The results show that although the proposed neural network model has fewer layers and relatively simple structure, it can realize the high-precision modeling of piezoelectric hysteresis dynamics at a lower computational cost. The experimental data shows that, under the excitation of 60 Hz input signal, the model's PV error only accounts for 0.82% of the full scale range, and the modeling performance is far superior to other models.

Designing an Improved Method to Determine the Anhysteretic Curve in Soft Magnetic Materials via the Jiles-Atherton Model

Designing an Improved Method to Determine the Anhysteretic Curve in Soft Magnetic Materials via the Jiles-Atherton Model

A nonlinear dynamic hysteresis model with magnetic–prestress–thermal coupling effect and dynamic electromagnetic losses of a giant magnetostrictive actuator

Compared with traditional actuators, the giant magnetostrictive actuator has the merits of fast response, high accuracy, and high reliability and has been widely applied. However, its performance is affected by the electromagnetic loss and the temperature, prestress, and magnetic coupling effect. In order to accurately analyze its performance, it is necessary to establish a nonlinear dynamic model including the electromagnetic loss and the magnetic–prestress–thermal coupling effect. First, based on the field separation approach, the magnetic fields generated by the eddy current loss and the anomalous loss are obtained and added to the Jiles–Atherton model. Second, the magnetostrictive model is given with the magnetic–prestress–thermal coupling effect. Finally, assuming the transmission of the giant magnetostrictive actuator as a mass–spring–damper system, a nonlinear dynamic hysteresis model with magnetic–prestress–thermal coupling effect and dynamic electromagnetic losses of a giant magnetostrictive actuator is developed. Based on this model, the output displacement curves of the giant magnetostrictive actuators under different driving currents and frequencies are given. The comparison with the experimental results shows that this model agrees well with the experiment.

An improvement of the Jiles-Atherton model at various magnetic field amplitudes using the example of Terfenol-D material

Jiles-Atherton (JA) model has been widely used to describe the magnetic hysteresis property of Terfenol-D material. However, the accuracy of the classic JA model is not convincing any more when it is employed to predict the magnetizations under various amplitudes of the applied magnetic fields. This paper measures the magnetic field and magnetization indirectly and approximates the measured results to the best of the classic static JA model. Then it shows that the JA model fails to describe the magnetic hysteresis effectively, especially in computing the hysteresis width. The high computational error is caused from inappropriate value of the pinning parameter to quantify the average energy required to break pinning site. Then the parameter is modified from the constant value to an independent variable on the field amplitude. From the comparisons on the results of the maximum magnetization, maximum magnetization, residual magnetization and coercivity, the performance in describing the hysteresis property of Terfenol-D is obviously promoted by the improved model apparently compared to the classic one.

Research on the stress magnetic coupling effect of a permalloy based on an optimized Jiles Atherton model in magnetic shielding devices

Magnetic shielding devices are extensively used in the measurement of quantum physics, the static magnetic field shielding layer made of permalloy in the magnetic shielding device will work under different stresses. Due to the magnetic properties of permalloy being sensitive to the applied stress, it is necessary to establish a magnetic property model considering stress to accurately evaluate the residual magnetic field in magnetic shielding devices under different stresses. However, the measurement and modeling of the magnetic properties of permalloy under different stresses have not been considered in relevant research. In this paper, the magnetic properties of permalloy under different tensile and compressive stresses were measured, and the optimized Jiles Atherton (JA) model of permalloy considering stress constructed. The parameters of the JA model are extracted by a genetic algorithm,-the particle swarm optimization algorithm, through measurement. Finally, the effectiveness of the model in predicting magnetic properties is validated. The JA optimization model considering stress can improve the calculation accuracy of magnetic shielding devices, which is of great significance for the design and application of magnetic shielding devices.

Magnetic noise modeling and calculation of Fe-based nanocrystalline in the SERF magnetometer considering temperature effects

The Fe-based nanocrystalline has been widely used in the innermost magnetic shielding of the spin-exchange relaxation-free (SERF) magnetometer due to its high permeability and low magnetic noise, which are significant factors limiting the sensitivity and accuracy of the measurements. However, the operating temperature of the inner shielding layer is around 80°C, and temperature has a significant impact on the magnetic noise of Fe-based nanocrystalline. To precisely analyze the magnetic noise of the Fe-based nanocrystalline in the SERF magnetometer, we first numerically simulate the 1K107 Fe-based nanocrystalline magnetic shielding barrel using the finite element method (FEM). Then, a variable-temperature dynamic Jiles-Atherton (VTDJA) model is proposed. The losses of 1K107 under various temperature are separated. The magnetic noise of 1K107 is computed using the Fluctuation-Dissipation theory. Finally, the magnetic noises of 1K107 at 25℃ and 80℃ are measured by setting up an experimental test system. Results show that the simulated deviation of the magnetic noise at 80°C and 25°C is 32 %, and the actual measured deviation is 48 %. The errors between simulated and measured magnetic noises at 25°C and 80°C are 5.29 % and 6.54 %, respectively. This study provides a novel method for the performance optimization of the SERF magnetometer.

Research on multi-scale hysteresis constitutive model of giant magnetostrictive materials considering multi-field coupling

The magnetization and magnetostrictive strain of giant magnetostrictive materials exhibit a complex nonlinear trend under the coupling of multiple fields, including magnetic field, temperature field, and prestress field. To enhance prediction accuracy, we propose a three-dimensional magnetic-thermal-force coupled nonlinear multi-scale hysteresis vector model. This model is derived from the principles of thermodynamics and continuum mechanics, taking into account the interactions among magnetic domains, grains, polycrystals, and macroscopic scales. It combines the volume-averaging principle of magnetic domain microscopy with the generalized Jiles-Atherton hysteresis model. The predicted hysteresis magnetization and magnetostrictive strain curves obtained from this model are in good agreement with experimental results. By analyzing the predicted hysteresis magnetization and magnetostrictive strain under different conditions, we demonstrate that our proposed model can comprehensively describe the effects of temperature and prestress on the multi-field coupled hysteresis behaviors of giant magnetostrictive materials. Moreover, it provides theoretical guidance for both macroscopic and microscopic optimization in designing active devices incorporating super magnetostrictive materials.

Analysis and Design of Adjustable-Gap Double-Side Axial Flux Permanent Magnet Hysteresis Damper

In this paper, a novel adjustable gap double-side axial flux permanent magnet hysteresis damper (AGDSAPHD) is proposed, of which the torque can be adjusted by changing the air gap and the magnetic field angle between the upper and lower stators at the same time. To analyze and design, a modified vector Jiles-Atherton (JA) hysteresis model is used for simulating the magnetic flux distribution and the hysteresis torque of AGDSAPHD. The eddy currents in the AGDSAPHD are analyzed, which have a great influence on the output torque when the rotational speed is fast. A splitting method used in the rotor of the AGDSAPHD is proposed to reduce the effect of eddy currents. The heat distribution of the AGDSAPHD is calculated to determine its slip power and operating mode. A prototype is built and tested to verify the reliability of the analysis. The experiments prove that the modified vector JA model has high computational accuracy in calculating the hysteresis effects of the AGDSAPHD. A splitting method used in the rotor can greatly reduce the eddy current torque. AGDSAPHD has a greater torque adjustment range and better temperature stability than the traditional one.

Study on the magnetic shielding properties of nanocrystalline strips under bending stress

The study of the magnetic properties of nanocrystalline materials under stress is of great significance for the construction of small and lightweight magnetic shielding rooms. Therefore, this paper investigates the effect of stress on the magnetic properties of nanocrystalline materials under the action of external bending stress. By comparing the test results of the soft magnetic measuring device with and without bending stress, it is found that the magnetic permeability (μ i) decreases by about 51.41% when the introduced bending stress σ is increased by about 5.96 × 107 pa, whereas the KuFe−Si (induced magnetic anisotropy constant) and Hk (field of magnetic anisotropy) increase by 5.30 × 102 J m–3 and 1.08 × 102 A m−1, respectively. The Jiles-Atherton (J-A) model considering the bending stress and radius of change correlation is established, and the typical parameters of the J-A model are fitted using the Gazelle Optimization Algorithm (GOA), and the RMSE (root mean square error) of all of them are less than 0.056 T. The magnetic domain density increased with the increase of bending stress, which verified the correlation between the J-A model parameters and the bending stress. Our results reveal that the nanocrystalline macroscopic and micromechanical magnetic properties can be effectively combined with the J-A model, which will provide a theoretical basis for the simulation study of the nanocrystalline magnetic shielding device in the actual stress situation.

Linearising anhysteretic magnetisation curves: A novel algorithm for finding simulation parameters and magnetic moments

This paper proposes a new method for determining the simulation parameters of the Jiles–Atherton Model used to simulate the first magnetisation curve and hysteresis loop in ferromagnetic materials. The Jiles–Atherton Model is an important tool in engineering applications due to its relatively simple differential formulation. However, determining the simulation parameters for the anhysteretic curve is challenging. Several methods have been proposed, primarily based on mathematical aspects of the anhysteretic and first magnetisation curves and hysteresis loops. This paper focuses on finding the magnetic moments of the material, which are used to define the simulation parameters for its anhysteretic curve. The proposed method involves using the susceptibility of the material and a linear approximation of a paramagnet to find the magnetic moments. The simulation parameters can then be found based on the magnetic moments. The method is validated theoretically and experimentally and offers a more physical approach to finding simulation parameters for the anhysteretic curve and a simplified way of determining the magnetic moments of the material.

Comparison of Dynamic Loss Inclusion Under Asymmetrical Minor Loops Using Lavers Formula and Inverse Jiles–Atherton Model

Comparison of Dynamic Loss Inclusion Under Asymmetrical Minor Loops Using Lavers Formula and Inverse Jiles–Atherton Model

Anisotropic Hysteresis Representation of Steel Sheets Based on a Vectorization Technique Applied to Jiles–Atherton Model

Anisotropic Hysteresis Representation of Steel Sheets Based on a Vectorization Technique Applied to Jiles–Atherton Model

Magnetic characterization of steel strips using transient field measurements: global sensitivity analysis and regression from a machine-learning perspective

In this contribution, the magnetic characterization of steel strips is studied using synthetic data of field-gradient transients, which have been produced via the finite integration technique. The material law is described and parameterized using the Jiles–Atherton model. The sensitivity of relevant magnetic indicators with respect to the material parameters is then analyzed using two global methods: Sobol’ indices and δ-sensitivity indices. In order to accelerate the evaluation of these quantities, a fast metamodel is built using machine learning techniques from a simulated dataset. The solution of the inverse problem based on a tailored learning framework is tested for the different proposed identifiers, and their suitability for the magnetic characterization of the material in question is finally discussed.

Hysteresis measurement and generic modeling of magnetostrictive materials under high-frequency excitation and high-intensity bias field

The applied DC (direct-current) bias fields can cause the changes of hysteresis and loss properties of magnetostrictive alloys materials, which further affect the output characteristics of electromagnetic devices. This study investigates the impact of high-frequency AC (alternating-current) excitation and high intensity DC bias magnetic field on hysteresis characterization for different magnetostrictive materials. To obtain the hysteresis properties of materials, a generic dynamic magnetic measured system is established, which can test the low-permeability magnetic materials with a DC bias strength range of 0–20000 A/m at AC excitation frequency range of 1–9 kHz. The tested results show that the Terfenol-D, Fe83Ga17, and Fe30Co70 exhibit different DC bias sensitivities, which cause the largest deviation (31.68 %) of losses compared with unapplied DC bias field. To better predict these changes, a generic high-frequency dynamic Jiles-Atherton (J-A) model with the coupling AC excitation and DC bias field is proposed. The AC excitation and DC bias related terms are introduced to characterize distortion and ellipticity phenomenon for these hysteresis loops. A combined method of Simulated Annealing Particle Swarm Optimization-Linear Decreasing Inertia Weight (SA-PSO-LDIW) algorithm and Neural Network (NN) are proposed to identify the introduced relevant parameters. This paper solves the problem of high-frequency hysteresis measurement and loss calculation for low permeability and high electrical impedance magnetostrictive rods-shaped material which can help guide the high frequency application for magnetostrictive materials.

Experimental measurements and numerical modelling of additively manufactured Fe-Si cores

This paper presents experimental measurements and numerical computations for toroidal Fe-Si cores made by means of additive manufacturing (AM). The production technique of the samples is based on laser powder bed fusion (LPBF). Two different approaches, the Jiles–Atherton (JA) model and an artificial neural network (ANN), have been implemented and compared to represent the hysteretic behaviour of the samples made. The models are identified using experimental measurements at quasi-static rate for a bulk toroidal core. Their accuracy and reliability are evaluated by means of a comparison between simulations and measurements for a different data set. Moreover, a specific JA approach is implemented on the finite element scheme to evaluate its usefulness in the simulations of dynamic magnetization processes with not negligible eddy current effects.

The method of moments in Jiles–Atherton model based magnetostatic modelling of thin layers

The method of moments in Jiles–Atherton model based magnetostatic modelling of thin layers

Numerical analysis of the frequency-dependent Jiles-Atherton hysteresis model using the example of Terfenol-D material

<p>The Jiles-Atherton model has been widely used in describing the hysteretic property of a magnetic material or device. However, the calculation errors are not so easily discovered. With a complex expression, the frequency-dependent Jiles-Atherton model should be solved numerically with appropriate settings. This paper proposes an effective solving method for this model and describes some necessary analysis built on the numerical results. In the numerical method proposed in this manuscript, the anhysteretic magnetization was calculated by the secant method, and the trapezoidal rule was utilized to form the implicit function, which can be calculated by the fixed-point iteration. Compared to the other common methods, the proposed one has a friendly expression and fast computation speed. The Terfenol-D material was taken as an example for the numerical analysis. The feasible region was determined and the commonly used approximation that neglects the term of the magnetic field when calculating the magnetic induction intensity was tested. At last, the required number of sampling points per period was reached to guarantee high precision from analyzing its influence on the computation precision. The proposed numerical method is helpful for high-precision solutions of the frequency-dependent Jiles-Atherton model. The results from the numerical analysis can also help users avoid some incorrect calculations when employing this hysteresis model.</p>

Limitations of Jiles–Atherton models to study the effect of hysteresis in electrical steels under different excitation regimes

PurposeThe accurate modeling of magnetic hysteresis in electrical steels is important in several electrical and electronic applications. Numerical models have long been known that can correctly reproduce some typical behaviours of these magnetic materials. Among these, the model proposed by Jiles and Atherton must certainly be mentioned. This model is intuitive and fairly easy to implement and identify with relatively few experimental data. Also, for this reason, it has been extensively studied in different formulations. The developments and numerical tests made on this hysteresis model have indicated that it is able to accurately reproduce symmetrical cycles, especially the major loop, but often it fails to reproduce non-symmetrical cycles. This paper aims to show the positive aspects and highlight the defects of the different formulations in predicting the minor loops of electrical steels excited by non-sinusoidal currents.Design/methodology/approachThe different formulations are applied to different electrical steels, and the data coming from the simulations are compared with those measured experimentally. The direct and inverse Jiles–Atherton models, including the introduction of the dissipative factor approach, are presented, and their limitations are proposed and validated using the measurements of three non-grain-oriented materials. Only the measured major loop is used to identify the parameters of the Jiles–Atherton model. Furthermore, the direct and inverse Jiles–Atherton models were used to simulate the minor loops as well as the hysteresis cycles with direct component (DC) bias excitation. Finally, the simulation results are discussed and compared to measurements for each study case.FindingsThe paper indicates that both the direct and the inverse Jiles–Atherton model formulations provide a good agreement with the experimental data for the major loop representation; nevertheless, both models can not accurately predict the minor loops even when the modification approaches proposed in the literature were implemented.Originality/valueThe Jiles–Atherton model and its modifications are widely discussed in the literature; however, some limitations of the model and its modification in the case of the distorted current waveform are not completely highlighted. Furthermore, this paper contains an original discussion on the accuracy of the prediction of minor loops from distorted current waveforms, including DC bias.