scholarly journals Unified First Order Inertial Element Based Model of Magnetostrictive Hysteresis and Lift-Off Phenomenon

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1689
Author(s):  
Roman Szewczyk
Keyword(s):  
Hysteresis Loops ◽  
Boltzmann Distribution ◽  
Unified Approach ◽  
Local Maxima ◽  
First Order ◽  
Inertial Element ◽  
Proposed Model ◽  
Magnetostrictive Actuators ◽  
Lift Off ◽  
Good Agreement

The present paper presents a new model of magnetostrictive hysteresis loop. A unified approach of both the hysteresis of λ(B) relation, as well as the lift-off phenomenon is proposed, which are explained together on the base of the response of the first order inertial element. Considering previously presented reports, the Maxwell–Boltzmann distribution based model of magnetostrictive characteristics with local maxima, enables modeling magnetostrictive loops. The model was validated on the results of measurements of magnetostrictive hysteresis loops of Mn0.70Zn0.24Fe2.06O4 ferrite for power applications. Good agreement was confirmed for major magnetostrictive loop, especially for smaller values of flux density. As a result, the proposed model may be used for modeling the magnetostrictive response of inductive components of electrical machines, power conversion devices or magnetostrictive actuators.

scholarly journals Model of the Magnetostrictive Hysteresis Loop with Local Maximum

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 105 ◽  
Author(s):  
Roman Szewczyk
Keyword(s):  
Hysteresis Loop ◽  
Hysteresis Loops ◽  
Local Maximum ◽  
Boltzmann Distribution ◽  
Wall Movement ◽  
Construction Steel ◽  
Proposed Model ◽  
Lift Off ◽  
Power Application ◽  
Good Agreement

This paper presents a model of the magnetostrictive hysteresis loop with local maximum. The model is based on the differential equations describing magnetostriction due to the domain wall movement as well as domain magnetization rotation. The transition between these mechanisms of magnetization is quantified by the Maxwell–Boltzmann distribution. Moreover, the lift-off phenomenon in the magnetostrictive hysteresis loop is considered. The proposed model was validated on the results of measurements of magnetostrictive hysteresis loops of Mn0.70Zn0.24Fe2.06O4 ferrite for power application and 13CrMo4-5 construction steel. The results of modeling confirm that the proposed model corresponds well with experimental results. Good agreement was confirmed by determination coefficient R2, which exceeded 0.995 and 0.985 for Mn0.70Zn0.24Fe2.06O4 ferrite for power application and 13CrMo4-5 construction steel, respectively.

Unified Second-Order Stochastic Averaging Approach

1997 ◽  
Vol 64 (2) ◽  
pp. 281-291 ◽  
Author(s):  
M. Hijawi ◽  
N. Moschuk ◽  
R. A. Ibrahim
Keyword(s):  
Order Approximation ◽  
Stochastic Averaging ◽  
Nonlinear Damping ◽  
Second Order ◽  
Unified Approach ◽  
Order Analysis ◽  
First Order ◽  
Different Types ◽  
First Order Approximation ◽  
Good Agreement

First-order stochastic averaging has proven very useful in predicting the response statistics and stability of dynamic systems with nonlinear damping forces. However, the influence of system stiffness or inertia nonlinearities is lost during the averaging process. These nonlinearities can be recaptured only if one extends the stochastic averaging to second-order analysis. This paper presents a systematic and unified approach of second-order stochastic averaging based on the Stratonovich-Khasminskii limit theorem. Response statistics, stochastic stability, phase transition (known as noise-induced transition), and stabilization by multiplicative noise are examined in one treatment. A MACSYMA symbolic manipulation subroutine has been developed to perform the averaging processes for any type of nonlinearity. The method is implemented to analyze the response statistics of a second-order oscillator with three different types of nonlinearities, excited by both additive and multiplicative random processes. The second averaging results are in good agreement with those estimated by Monte Carlo simulation. For a special nonlinear oscillator, whose exact stationary solution is known, the second-order averaging results are identical to the exact solution up to first-order approximation.

An Analytical Transient Tire Model

2001 ◽  
Vol 29 (2) ◽  
pp. 108-132 ◽  
Author(s):  
A. Ghazi Zadeh ◽  
A. Fahim
Keyword(s):  
Transient Behavior ◽  
Stability Control ◽  
Vehicle Stability ◽  
Tire Model ◽  
Steering Angle ◽  
First Order ◽  
Vehicle Stability Control ◽  
Proposed Model ◽  
Depth Study ◽  
And Performance

Abstract The dynamics of a vehicle's tires is a major contributor to the vehicle stability, control, and performance. A better understanding of the handling performance and lateral stability of the vehicle can be achieved by an in-depth study of the transient behavior of the tire. In this article, the transient response of the tire to a steering angle input is examined and an analytical second order tire model is proposed. This model provides a means for a better understanding of the transient behavior of the tire. The proposed model is also applied to a vehicle model and its performance is compared with a first order tire model.

scholarly journals Compact Modelling of Electrical, Optical and Thermal Properties of Multi-Colour Power LEDs Operating on a Common PCB

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1286
Author(s):  
Krzysztof Górecki ◽  
Przemysław Ptak
Keyword(s):  
Integrated Circuits ◽  
Optical Model ◽  
Printed Circuit Board ◽  
Circuit Board ◽  
Junction Temperature ◽  
Optical Parameters ◽  
Spice Simulation ◽  
Light Emitting ◽  
Proposed Model ◽  
Good Agreement

This paper concerns the problem of modelling electrical, thermal and optical properties of multi-colour power light-emitting diodes (LEDs) situated on a common PCB (Printed Circuit Board). A new form of electro-thermo-optical model of such power LEDs is proposed in the form of a subcircuit for SPICE (Simulation Program with Integrated Circuits Emphasis). With the use of this model, the currents and voltages of the considered devices, their junction temperature and selected radiometric parameters can be calculated, taking into account self-heating phenomena in each LED and mutual thermal couplings between each pair of the considered devices. The form of the formulated model is described, and a manner of parameter estimation is also proposed. The correctness and usefulness of the proposed model are verified experimentally for six power LEDs emitting light of different colours and mounted on an experimental PCB prepared by the producer of the investigated devices. Verification was performed for the investigated diodes operating alone and together. Good agreement between the results of measurements and computations was obtained. It was also proved that the main thermal and optical parameters of the investigated LEDs depend on a dominant wavelength of the emitted light.

Analysis of the First Order and Slowly Varying Motions of an Axisymmetric Floating Body in Bichromatic Waves

2013 ◽  
Vol 135 (1) ◽  
Author(s):  
João Pessoa ◽  
Nuno Fonseca ◽  
C. Guedes Soares
Keyword(s):  
Vertical Cylinder ◽  
Vertical Axis ◽  
Second Order ◽  
The Body ◽  
Floating Body ◽  
Drift Motion ◽  
First Order ◽  
Motion Responses ◽  
Simple Geometry ◽  
Good Agreement

The paper presents an experimental and numerical investigation on the motions of a floating body of simple geometry subjected to harmonic and biharmonic waves. The experiments were carried out in three different water depths representing shallow and deep water. The body is axisymmetric about the vertical axis, like a vertical cylinder with a rounded bottom, and it is kept in place with a soft mooring system. The experimental results include the first order motion responses, the steady drift motion offset in regular waves and the slowly varying motions due to second order interaction in biharmonic waves. The hydrodynamic problem is solved numerically with a second order boundary element method. The results show a good agreement of the numerical calculations with the experiments.

Static and Dynamic Structure of Molecular Monomers and Dimers of the Rare-earth Fluorides

2001 ◽  
Vol 56 (5) ◽  
pp. 381-385
Author(s):  
Z. Akdeniz ◽  
M . Gaune-Escard ◽  
M. P. Tosi
Keyword(s):  
Rare Earth ◽  
Bond Length ◽  
Geometrical Structure ◽  
Vibrational Mode ◽  
Dynamic Structure ◽  
Molecular Shape ◽  
Proposed Model ◽  
Infrared Studies ◽  
Charged Clusters ◽  
Good Agreement

Abstract We determine a model of the ionic interactions in RF3 compounds, where R is a rare-earth element in the series from La to Lu, by an analysis of data on the bond length and the vibrational mode frequencies of the PrF3, GdF3 and HoF3 molecular monomers. All RF3 monomers are predicted to have a pyramidal shape, displaying a progressive flattening of the molecular shape in parallel with the lanthanide contraction of the bond length. The vibrational frequencies of all monomers are calculated, the results being in good agreement with the data from infrared studies of matrix-isolated molecules. We also evaluate the geometrical structure and the vibrational spectrum of the La2F6 and Ce2F6 dimers, as a further test of the proposed model. -PACS 36.40.Wa (Charged clusters)

Vulcanization of Elastomers. 23. The Chemical Kinetics of Vulcanization Reactions and The Physical Properties of The Vulcanizates. I

1960 ◽  
Vol 33 (2) ◽  
pp. 335-341
Author(s):  
Walter Scheele ◽  
Karl-Heinz Hillmer
Keyword(s):  
Activation Energy ◽  
Physical Properties ◽  
Chemical Kinetics ◽  
Kcal Mole ◽  
First Order ◽  
Equilibrium Swelling ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization ◽  
Limiting Value ◽  
Good Agreement

Abstract As a complement to earlier investigations, and in order to examine more closely the connection between the chemical kinetics and the changes with vulcanization time of the physical properties in the case of vulcanization reactions, we used thiuram vulcanizations as an example, and concerned ourselves with the dependence of stress values (moduli) at different degrees of elongation and different vulcanization temperatures. We found: 1. Stress values attain a limiting value, dependent on the degree of elongation, but independent of the vulcanization temperature at constant elongation. 2. The rise in stress values with the vulcanization time is characterized by an initial delay, which, however, is practically nonexistent at higher temperatures. 3. The kinetics of the increase in stress values with vulcanization time are both qualitatively and quantitatively in accord with the dependence of the reciprocal equilibrium swelling on the vulcanization time; both processes, after a retardation, go according to the first order law and at the same rate. 4. From the temperature dependence of the rate constants of reciprocal equilibrium swelling, as well as of the increase in stress, an activation energy of 22 kcal/mole can be calculated, in good agreement with the activation energy of dithiocarbamate formation in thiuram vulcanizations.

Models for New Corrugated and Porous Solar Air Collectors under Transient Operation

2017 ◽  
Vol 42 (1) ◽  
Author(s):  
Qahtan Adnan Abed ◽  
Viorel Badescu ◽  
Adrian Ciocanea ◽  
Iuliana Soriga ◽  
Dorin Bureţea
Keyword(s):  
Climatic Conditions ◽  
Meteorological Conditions ◽  
Bias Error ◽  
First Order ◽  
Solar Air Collector ◽  
Section Surface ◽  
South Eastern Europe ◽  
Main Components ◽  
Theoretical Results ◽  
Good Agreement

AbstractMathematical models have been developed to evaluate the dynamic behavior of two solar air collectors: the first one is equipped with a V-porous absorber and the second one with a U-corrugated absorber. The collectors have the same geometry, cross-section surface area and are built from the same materials, the only difference between them being the absorbers. V-corrugated absorbers have been treated in literature but the V-porous absorbers modeled here have not been very often considered. The models are based on first-order differential equations which describe the heat exchange between the main components of the two types of solar air heaters. Both collectors were exposed to the sun in the same meteorological conditions, at identical tilt angle and they operated at the same air mass flow rate. The tests were carried out in the climatic conditions of Bucharest (Romania, South Eastern Europe). There is good agreement between the theoretical results and experiments. The average bias error was about 7.75 % and 10.55 % for the solar air collector with “V”-porous absorber and with “U”-corrugated absorber, respectively. The collector based on V-porous absorber has higher efficiency than the collector with U-corrugated absorber around the noon of clear days. Around sunrise and sunset, the collector with U-corrugated absorber is more effective.

Doppler-Shifted Cyclotron Resonance in Thin Metal Films

1972 ◽  
Vol 50 (18) ◽  
pp. 2122-2137
Author(s):  
R. Turner ◽  
J. F. Cochran
Keyword(s):  
Magnetic Field ◽  
Metal Films ◽  
Thin Metal Film ◽  
Thin Metal ◽  
Free Electrons ◽  
Fermi Surfaces ◽  
First Order ◽  
Simple Quantum ◽  
The Magnetic Field ◽  
Good Agreement

According to Van Gelder the microwave absorption by a thin metal film in the presence of a static magnetic field normal to the film contains a series of peaks as the magnetic field is varied. In the present paper it is argued that these peaks correspond to Doppler-shifted cyclotron resonances of the carriers in the metal due to the quantization of electron momenta normal to the plane of the film. A simple quantum calculation is presented for the case of free electrons where the film is thin enough that to first order the microwave fields within are determined only by the boundary conditions and Maxwell's equations. The quantum expression is in good agreement with the absorption calculated using semiclassical arguments which can be readily extended to more complicated Fermi surfaces.

Plates in Unilateral Contact With Simple Supports: Pressure Loading

1986 ◽  
Vol 53 (1) ◽  
pp. 141-145 ◽  
Author(s):  
N. J. Salamon ◽  
T. P. Pawlak ◽  
F. F. Mahmoud
Keyword(s):  
Support System ◽  
Unilateral Contact ◽  
Response Mode ◽  
Pressure Loading ◽  
Analytical Work ◽  
Simple Supports ◽  
Square Plate ◽  
Lift Off ◽  
Good Agreement ◽  
Shear Fields

The response of a square plate, simply and unilaterally supported, to pressure loading is numerically treated. The support system consists of discrete elastic springs whose stiffnesses range from near-rigid to compliant character. It is found that, except for rather low support stiffnesses, the plate will lift off the foundation. After demonstrating good agreement with a recent analytical work, the deflections and shear fields are provided. The response mode changes dramatically as the supports approach rigidity.

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