International Journal of Applied Electromagnetics and Mechanics - Volume 39, issue 1-4

Authors: Roskosz, Maciej | Bieniek, Michał

Article Type: Research Article

Abstract: Distributions of the residual magnetic field (RMF) were compared to the results of the calculations of plastic strain and residual stress for samples made of 7CrMoVTiB10-10 (T/P24) steel. The RMF was measured on the surface of samples with a various degree of strain. The calculations of the stress and strain state were conducted by means of the finite elements method with the use of a bilinear model of the material. Qualitative and quantitative relationships were found …between plastic strain and the RMF components, as well as between residual stress and the RMF component derivatives. On the basis of the found relationships, the algorithm for the evaluation of residual stress was developed and preliminarily verified using the measurements of the RMF components. The trends of further research aiming to confirm the practical suitability of the developed algorithm for the evaluation of the stress and strain state were formulated. Show more

Keywords: Residual magnetic field, residual stress evaluation

DOI: 10.3233/JAE-2012-1505

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 521-527, 2012

Authors: Davino, Daniele | Giustiniani, Alessandro | Iannelli, Luigi | Visone, Ciro

Article Type: Research Article

Abstract: Magnetostrictive actuators are employed for several purposes but, often, the control strategy is strongly affected by their hysteretic behavior. Such issue becomes crucial if dynamic mechanical stress conditions apply. Indeed, the stress must be considered as an additional input. Nevertheless, a compensation scheme with two-input variables can be defined and fruitfully utilized in a suitable invertibility region. In this paper, different control strategies, based on a compensation algorithm able to take into account the …applied mechanical stress, are proposed and compared with simpler linear controllers in a real-time setup. Experimental data measured over a magnetostrictive actuator are presented and commented. Show more

Keywords: Magnetostriction, magnetostrictive devices, control systems, hysteresis, real-time experiments

DOI: 10.3233/JAE-2012-1506

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 529-534, 2012

Authors: Ido, Yasushi | Hayashi, Koichi | Kawai, Takuma

Article Type: Research Article

Abstract: Damping properties of a damper utilizing magnetic particles are investigated experimentally. A group of magnetic particles is treated as the working fluid in a damper instead of oil. In the presence of magnetic field, the damping force of the particles damper drastically increases. The maximum damping force appears near the dead center of vibration and higher frequency produces stronger maximum damping force, when the vibration frequency is in the range of low frequency below 5 Hz.

Keywords: Damper, magnetic particle, magnetic interaction, friction, damping force

DOI: 10.3233/JAE-2012-1507

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 535-540, 2012

Authors: Chukwuchekwa, Nkwachukwu | Moses, Anthony | Anderson, Phil

Article Type: Research Article

Abstract: Magnetic Barkhausen Noise (MBN) can be used for non-destructive evaluation of structural properties of ferromagnetic materials. An EMF due to Barkhausen noise is induced in a coil near the surface or encircling a ferromagnetic material which is subjected to an alternating external magnetic field. MBN measurements were carried out on samples of Non Grain-Oriented (NG0) steel to determine the variation with thickness and silicon content. The results show that the rms value of Barkhausen Noise (BN) …amplitude increases with decreasing sample thickness and increasing silicon content. This is explained in terms of eddy current effects which increase with increasing sample thickness and reduce with increasing silicon content. Moving domain walls induce eddy currents in the sample which give rise to effective retarding pressures on the walls which in turn leads to reduced magnetic Barkhausen noise amplitude. Show more

Keywords: Magnetic Barkhausen Noise, non-oriented steel, domain walls

DOI: 10.3233/JAE-2012-1508

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 541-545, 2012

Authors: Xiao, Ling | Ding, Chunhua | Sun, Yanhua | Yang, Lihua | Yu, Lie

Article Type: Research Article

Abstract: To analyze the influence of the component size ratio (matrix/inclusion) on the densification and magnetic property, the equivalent model of SMCs at particle scale was used for static case. The relation of porosity, density against the component size ratio δ is deduced. To calculate the effective permeability of the model, the equivalent magnetic circuit method and magnetic energy method are proposed and compared. The results show that the densification and effective permeability are …dependent on the component size ratio. The effect of porosity is even more pronounced for the effective permeability. In addition, the results of this model are consistent with the experimental results. Show more

Keywords: Soft magnetic composites, particle sizes ratio, porosity, effective permeability

DOI: 10.3233/JAE-2012-1509

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 547-553, 2012

Authors: Di Barba, Paolo | Dughiero, Fabrizio | Dusi, Maurizio | Forzan, Michele | Mognaschi, Maria Evelina | Paioli, Mauro | Sieni, Elisabetta

Article Type: Research Article

Abstract: Purpose of the paper is to study the behaviour of a submerged arc furnace for the production of ferroalloys in order to implement a new voltage-based control system of the furnace. A 3D Finite Element (FE) model has been developed to define an equivalent electric circuit model able to describe the furnace operations. Both field and circuit models are validated by measurements on a furnace installed in an industrial plant. A novel method to control a …furnace is proposed. Show more

Keywords: Finite element analysis, submerged arc furnace, voltage control

DOI: 10.3233/JAE-2012-1510

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 555-561, 2012

Authors: Nakamura, Akihiro | Suzuoka, Satoshi | Sawada, Tatsuo

Article Type: Research Article

Abstract: The two-dimensional channel flow of a magnetic fluid was experimentally investigated. When a magnetic field is applied to a magnetic fluid, ferromagnetic particles aggregate along the direction of the magnetic field and form clusters. The pressure drop of the magnetic fluid flow changes according to cluster formations. The effect of the applied magnetic field on the pressure drop was determined. The ultrasonic propagation velocity was also measured to clarify the effect of cluster formations.

Keywords: Magnetic fluid, two-dimensional flow, cluster, pressure drop, ultrasonic propagation velocity

DOI: 10.3233/JAE-2012-1511

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 563-568, 2012

Authors: Moroka, Yoshitaka | Isnikurniawan, Ahmad | Ohba, Hiromichi | Sawada, Tatsuo

Article Type: Research Article

Abstract: We carried out an impact experiment in order to investigate the influence of magnetic field intensity and inner diameter of the orifice on MR fluid motion under an impact load. The experiment was conducted by measuring the piston displacement. From the piston displacement, its velocity and acceleration were calculated.

Keywords: magnetorheological fluid, magnetic field, impact load, orifice

DOI: 10.3233/JAE-2012-1512

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 569-573, 2012

Authors: Lee, Hyung-Don | Nam, Yun-Joo | Park, Myeong-Kwan

Article Type: Research Article

Abstract: This paper is concerned with an electromagnetic design methodology for a magneto-rheological (MR) valve. In order to improve the performance of the MR valve, the magnetic circuit consisting of the MR fluid, the yoke for forming the magnetic flux path, and the electromagnetic coil should be effectively designed. For this purpose, two effective approaches are proposed: one is to shorten the magnetic flux path by removing the unnecessary bulk of the yoke to improve the static …characteristic of the MR valve, and the other is to increase the magnetic reluctance of the magnetic circuit by minimizing the cross-sectional area of the yoke through which the magnetic flux passes to improve the dynamic and hysteretic characteristics. After two MR valves, one is a conventional type valve and the other is the proposed one, are designed and fabricated, their performances are evaluated through magnetic field analysis and a series of basic experiments. Show more

Keywords: Magneto-rheological fluid, MR valve, electromagnetic design

DOI: 10.3233/JAE-2012-1513

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 575-581, 2012

Authors: Motozawa, Masaaki | Chang, Jia | Sawada, Tatsuo | Kawaguchi, Yasuo

Article Type: Research Article

Abstract: Forced convective heat transfer characteristics in a rectangular duct flow of a magnetic fluid under a magnetic field were investigated experimentally. Experiments were performed in which the magnetic field intensity was changed from 0 mT to 500 mT. The Reynolds number based on the hydraulic diameter was set to 820 (laminar flow), 1630 and 2450 (turbulent flow). The magnetic fluid in the rectangular duct was heated with a uniform heat flux. The results of the experiments …showed that in the case of laminar flow of the magnetic fluid, when the magnetic field is applied to the magnetic fluid flow, the heat transfer coefficient increases locally in the region where the magnetic field exists. In contrast, in the turbulent flow of the magnetic fluid, heat transfer is not enhanced, but slightly decreases. Show more

Keywords: Magnetic fluid, Forced convective heat transfer, Rectangular duct

DOI: 10.3233/JAE-2012-1514

Citation: International Journal of Applied Electromagnetics and Mechanics, vol. 39, no. 1-4, pp. 583-588, 2012