DOCSLIB.ORG

Magnetic Shape Memory Alloys As Smart Materials for Micro-Positioning Devices

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Magnetic Shape Memory Alloys As Smart Materials for Micro-Positioning Devices Magnetic Shape Memory Alloys as smart materials for micro-positioning devices. Arnaud Hubert, Nandish Calchand, Yann Le Gorrec, Jean-Yves Gauthier To cite this version: Arnaud Hubert, Nandish Calchand, Yann Le Gorrec, Jean-Yves Gauthier. Magnetic Shape Memory Alloys as smart materials for micro-positioning devices.. Advanced Electromagnetics Symposium, AES’12., Apr 2012, TELECOM PARISTECH, Paris, France. pp.1-10. hal-00720674 HAL Id: hal-00720674 https://hal.archives-ouvertes.fr/hal-00720674 Submitted on 25 Jul 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Magnetic Shape Memory Alloys as smart materials for micro-positioning devices A. Hubert1∗, N. Calchand1, Y. Le Gorrec1, J.-Y. Gauthier2 1Institut Femto-ST UMR 6174, UFC/ENSMM/UTBM/CNRS, 24 rue Alain Savary, 25000 Besanc¸on, France 2Laboratoire Amp`ere UMR 5005, Universit´ede Lyon/CNRS, INSA Lyon, bˆatiment A. de Saint-Exup´ery, Avenue Jean Capelle, 69621 Villeurbanne cedex, France *corresponding author, E-mail: [email protected] Abstract most used adaptive materials for positioning application. Nevertheless, alternative solutions exist and MSMAs are a In the field of microrobotics, actuators based on smart ma- class of active materials which typically generate 6% strain terials are predominant because of very good precision, in- in response to externally applied magnetic fields [12]. In tegration capabilities and high compactness. This paper contrast to conventional heat driven shape memory alloys presents the main characteristics of Magnetic Shape Mem- (SMAs), the magnetically driven MSMAs exhibit higher ory Alloys as new candidates for the design of micromecha- operating frequency, making them attractive for actuation tronic devices. The thermo-magneto-mechanical energy applications. Most of the work on characterization and conversion process is first presented followed by the ade- modeling of MSMAs has been focused on quasistatic ac- quate modeling procedure required to design actuators. Fi- tuation, i.e., strain dependence on magnetic field. Very few nally, some actuators prototypes realized at the Femto-ST studies take into account the dynamical behaviour and even institute are presented, including a push-pull bidirectional fewer propose MSMA based actuator prototypes. The pur- actuator. Some results on the control and performances of pose of this paper is to present a modeling proceduretaking these devices conclude the paper. into account the complex magneto-mechanicalbehaviors of MSMA and the dynamical characteristics of actuators at the 1. Introduction same time, to design new micropositioning devices. Electromagnetic devices have become promising con- tenders in the area of ultra-high precision manufacturing, Among all the offer concerning magnetic active materi- manipulation and sensing. Most of these promising new als, Magnetic Shape Memory Alloy is a relatively new can- technologies uses active/adaptive materials as a base for didate. It was first experimented in 1995/1996 at the MIT actuation principles because of compactness, integrations for the Ni-Mn-Ga alloy [13] and at the University of Min- and smart use capabilities [1, 2]. This paper reports recent nesota for the Fe-Pd alloy [14]. Since these first works, lots results obtained using a new type of smart material called of researchs have been conducted all around the world (see Magnetic Shape Memory Alloy (MSMA) which is an alloy [15, 16] for reviews) but very few concrete applications ex- of Ni-Mn-Ga. ist today due to the complex dynamic behaviour of MSMA and due to the difficulties to improve its manufacturing pro- Currently, most of the high-precision devices use piezo- cess. Currently, only single crystal samples present signifi- electric materials such as PZT because of their high- cant magneto-mechanical coupling characteristics and even dynamic bandwidth and their nearly linear behaviour. if a lot of studies are conducted concerning thin films de- Piezoelectric materials are used to design microposition- position and polycrystal samples [17, 18], these types of ing devices by using classical mode of working [3, 4] or structures are presently less adequate for actuation applica- by using stick and slip mode of working [5, 6]. In the tions because of a lower magneto-mechanical coupling. field of magnetic active materials, the main applications use magnetostrictive materials [7, 8] especially Terfenol- MSMA can be seen as a mixture of a classical shape D. This material is the most used because of the important memory alloy (SMA) and a magnetostrictive material. In progress in its performances since its first use in 1950 by a way, its microscopic behaviour is similar to SMAs but the Naval Ordnance Laboratory in the USA and its high strain is not only due to a martensite/austenite phase trans- magneto-mechanical coupling compared to the other mag- formation but is also due to a martensite reorientation un- netostrictive materials. Examples of actuators and position- der magnetic fields. In this second mode of working – ing devices using magnetostrictive materials can be found martensite rearrangement –, MSMA can be compared with in [9, 10, 11]. standard magnetostrictive materials but with a much more important magneto-mechanical coupling (6 % of maximal Piezoelectric and magnetostrictive materials are the strain for Ni-Mn-Ga instead of 0.16 % for Terfenol-D). Austenite Martensite variants This paper first explains the working principle of this active material and gives some tools for static and dy- m1 m namic behaviour modeling. Then, some design rules will 2 m be presented to propose efficient actuators. These mod- 3 A M1 M2 M3 eling works will be used as guidelines to design a new (a) micro-positioning stage. It will be based on two antag- onist MSMA-based actuators to perform a one-degree-of- freedom linear axis stage with a full-range motion of the y M1 Cooling + order of millimeters and a micrometers precision. Mea- A M2 x surements conducted on the prototype will be presented and + M3 commented. Heating Heating Stress application 2. Basis on MSMA modeling and behaviour Stress Stress M2 application 2.1. MSMA Properties and Characteristics M1 M2 M1 As seen before, the working principle of MSMA is quite Magnetic Magnetic field field application similar to the working of SMA but its actuation can also result from magnetic field application. This second mode (b) of working allows to increase significantly the dynami- cal bandwidth of the device because it uses a magneto- Figure 1: MSMA behaviour: (a) austenite phase and the mechanical energy conversion process instead of a thermo- three martensite variants and (b) martensitic reorientation: mechanical. Since fifteen years, these materials knew some effects of mechanical stress, magnetic field and tempera- improvements concerning mainly the working temperature ture. range and the maximum available strain. When actuated by magnetic fields, a large strain (6 to 10 %) is obtained with a response-time in the range of milliseconds (to com- pare with tenth of seconds or even seconds for SMA). Besides these interesting properties, the material also The MSMA used in this paper is a non-stoechiometric Ni- has some important drawbacks. They are the brittleness Mn-Ga monocrystal corresponding to the most currently of the single-crystal, the high required magnetic field (400 used MSMA materials. In this alloy, the martensite phase kA/m), the large dependence of the material parameters on appears in three different variants corresponding to the temperature changes, a small blocking stress (2-3 MPa) and three possible crystallographic directions in the sample (see a large hysteretical thermo-magneto-mechanical behaviour. Fig. 1 (a)). More details about the structural properties of this material The martensitic reorientation principle is presented in can be found in [15]. Fig. 1 (b): at high temperature, the MSMA sample is in austenitic phase (A). After a cooling process, the austenite 2.2. Quasi-Static Modeling of MSMA phase is transformed into a martensite phase without any favoured variants. Therefore the resulting sample contains Two theories can be used to model the behaviour of martensite variants into three equal portions (M1, M2 and MSMA: M3). If a mechanicalstress is applied in a specific direction, • The first one is based on microscopic properties and then the fraction of variant with its short axis in this direc- physics of solid. The following papers are represen- tion grows. If this stress is high enough then the sample will tative of the works done on MSMA materials with only contain this variant (for example M2 in Fig. 1 (b)). If this approach [19, 20, 21, 22]. the stress decreases, the volume fraction of the M2 variant also decrease but in an irreversible behaviour (large hystere- • The second one is based on macroscopic properties sis). In a same way, if a magnetic field is applied, the vari- and thermodynamics. In [23, 24, 25], such mod- ant with its easy magnetization axis in the field direction, is els are proposed whereas in [26, 27, 28], a more favoured. For MSMA, the easy magnetization direction is mechatronics-based approach is taken. They explic- the same as the short axis of the M1 variant. In this case, itly take into account the salient features (dynamics this variant fraction increases as shown in Fig. 1 (b) by the of system) required to make actuators. application of a magnetic field perpendicular to the stress field. The balance between magnetic field and mechanical While the first theory is prefered by physicists, the second stress allows a control of the macroscopic strain.
Load more

Recommended publications
  • Magnetostriction in Rare Earth Elements Measured with Capacitance Dilatometry
    Magnetostriction in Rare Earth Elements Measured with Capacitance Dilatometry Diplomarbeit zur Erlangung des akademischen Grades eines Magisters der Naturwissenschaften Betreuer: Dr. habil. Martin Rotter eingereicht von: Alexander Barcza Matrikelnummer: 9902823 Mai 2006 ii Eidesstattliche Erkl¨arung Ich, Alexander Barcza, geboren am 24.01.1981 in Sankt P¨olten, erkl¨are, 1. dass ich diese Diplomarbeit selbstst¨andig verfasst, keine anderen als die angegebe- nen Quellen und Hilfsmittel benutzt und mich auch sonst keiner unerlaubten Hilfen bedient habe, 2. dass ich meine Diplomarbeit bisher weder im In- noch im Ausland in irgen- deiner Form als Pr¨ufungsarbeit vorgelegt habe, Wien, am 27.05.2006 Unterschrift iii Kurzfassung Die vorliegende Diplomarbeit wurde im Zeitraum von September 2005 bis bis Mai 2006 verfasst. Die Arbeiten wurden teilweise an der Universit¨at Wien, an der Technischen Universit¨at Wien und am National High Magnetic Field Laboratory (NHMFL) Tallahassee, Florida durchgef¨uhrt. Das Thema der Arbeit ist die Mes- sung der thermischen Ausdehnung und der Magnetostriktion der Selten-Erd-Metalle Samarium und Thulium. Die Kapazit¨atsdilatometrie ist eine der empfindlichsten und deswegen am meisten eingesetzten Methoden, um diese Eigenschaften zu messen. Mit dieser Methode ist es m¨oglich, relative L¨angen¨anderungen im Bereich von 10−7 zu messen. Ein hoch entwickeltes Silber-Miniatur-Dilatometer wurde aus den Einzel- teilen zusammengebaut und an einer Serie von Standardmaterialien getestet. Das neue Dilatometer wurde auch in magnetischen Feldern von bis zu 45 T am weltweit f¨uhrenden NHMFL eingesetzt. Ein kurzer Uberblick¨ ¨uber die Technik zur Erzeugung hohe Magnetfelder, deren Vorteile und Grenzen wird gegeben. Weiters wird die K¨uhltechnik und die Stromversorgung des Forschungszentrums beschrieben.
    [Show full text]
  • The Mathematical Modeling of Magnetostriction
    THE MATHEMATICAL MODELING OF MAGNETOSTRICTION Katherine Shoemaker A Thesis Submitted to the Graduate College of Bowling Green State University in partial fulfillment of the requirements for the degree of MASTERS OF ART May 2018 Committee: So-Hsiang Chou, Advisor Kit Chan Tong Sun c 2018 Katherine Shoemaker All rights reserved iii ABSTRACT So-Hsiang Chou, Advisor In this thesis, we study a system of differential equations that are used to model the material deformation due to magnetostriction both theoretically and numerically. The ordinary differential system is a mathematical model for a much more complex physical system established in labo- ratories. We are able to clarify that the phenomenon of double frequency is more delicate than originally suspected from pure physical considerations. It is shown that except for special cases, genuine double frequency does not arise. In particular, simulation results using the lab data is consistent with the experiment. iv I dedicate this work to my family. Even if they don’t understand it, they understand so much more. v ACKNOWLEDGMENTS I would like to express my sincerest gratitude to my advisor Dr. Chou. He has truly inspired me and made my graduate experience worthwhile. His guidance, both intellectually and spiritually, helped me through all the time spent researching and writing this thesis. I could not have asked for a better advisor, or a better instructor and I am truly appreciative of all the support he gave. In addition, I would like to thank the remaining faculty on my thesis committee: Dr. Tong Sun and Dr. Kit Chan, for supporting me through their instruction and mentorship.
    [Show full text]
  • Magnetostrictive Properties of Mn0.70Zn0.24Fe2.06O4 Ferrite
    materials Article Magnetostrictive Properties of Mn0.70Zn0.24Fe2.06O4 Ferrite Adam Bie ´nkowskiand Roman Szewczyk * Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, 02-525 Warsaw, Poland; [email protected] * Correspondence: [email protected]; Tel.: +48-609-464741 Received: 18 September 2018; Accepted: 1 October 2018; Published: 3 October 2018 Abstract: This paper presents the results of measurements of magnetostrictive properties of Mn0.70Zn0.24Fe2.06O4 ferrite for power applications. Frame-shaped samples were used for measurements to guarantee a uniform magnetizing field and magnetostrictive strain distribution. Magnetostrictive hysteresis loops were measured by semiconductor strain gauges. The results indicate that the magnetostrictive characteristic of Mn0.70Zn0.24Fe2.06O4 ferrite is non-monotonic and magnetostriction changes have opposite signs for higher values of the magnetizing field. Keywords: power ferrites; Mn-Zn ferrites; magnetostriction 1. Introduction Magnetostriction is the most important magnetomechanical effect connected with the changes of the size of sample made of magnetic material subjected to a magnetizing field. In spite of the fact that the magnetostriction effect was described first in 1847 by Joule [1], this phenomenon is still not fully understood. Previously presented models of magnetostriction [2,3] are rather a general, qualitative explanation of magnetostriction mechanisms. Quantitative understanding of the magnetostrictive characteristics requires quantum effects-based models [4], which are still under development. In spite of the lack of sufficient quantitative models, magnetostriction has a great technical importance. Magnetostrictive strain is the main source of acoustic noise generated by transformers [5]. Moreover, magnetostriction can cause noise in signals from inductive components.
    [Show full text]
  • Magneto-Strictive, Magneto-Rheological & Ferrofluidic
    Magneto-strictive, Magneto-rheological & Ferrofluidic Materials Corso Materiali intelligenti e Biomimetici 2/04/2020 [email protected] Magnetic Properties Magnetic Permeability: indicates how easily a material can be magnetized. It is a constant of proportionality that exists between magnetic induction and magnetic field intensity. µr =µ/µ0 (relative permeability) -6 µ0=1.26 x 10 H/m in free space (vacuum) • Materials that cause the lines of flux to move farther apart, resulting in a decrease in magnetic flux density compared with a vacuum, are called diamagnetic; • materials that concentrate magnetic flux are called paramagnetic (non-ferrous metals such as copper, aluminum); • materials that concentrate the flux by a factor of more than ten are called ferromagnetic (iron, steel, nickel). Magnetic Properties • Diamagnetic: dipoles formed under the applied field H-> oriented in an opposite direction with respect to the applied H (no net magnetization) • Paramagnetic: existing random dipoles -> oriented in the same direction of the applied H (small magnetization) • Ferromagnetic: existing alligned dipoles -> oriented in the same direction of the applied H (large magnetization) domains Magneto-strictive materials (MS) Ferromagnetic materials have a structure that is divided into domains (regions of uniform magnetic polarization). When a magnetic field is applied, the domains rotate causing a change in the material dimensions. Magnetostriction is a property of ferromagnetic materials that causes them to change in shape of materials under the influence of an external magnetic field. Magnetostriction is a reversible exchange of energy between the mechanical and the magnetic domain (magneto-mechanical coupling). Magnetostriction The reason that a rotation of the magnetic domains of a material results in a change in the materials dimensions is a consequence of magneto-crystalline anisotropy: it takes more energy to magnetize a crystalline material in one direction than another.
    [Show full text]
  • Development of Iron-Rich Nanocrystalline Magnetic Materials to Minimize Magnetostriction for High Current Inductor Cores
    DEVELOPMENT OF IRON-RICH (FE1-X-YNIXCOY)88ZR7B4CU1 NANOCRYSTALLINE MAGNETIC MATERIALS TO MINIMIZE MAGNETOSTRICTION FOR HIGH CURRENT INDUCTOR CORES By ANTHONY MARTONE Submitted in partial fulfillment of the requirements For the degree of Master of Science Thesis Advisor: Dr. Matthew Willard Department of Materials Science and Engineering CASE WESTERN RESERVE UNIVERSITY August 2017 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the thesis of Anthony M Martone candidate for the degree of Master of Science*. Committee Chair Professor Matthew Willard Committee Member Professor David Matthiesen Committee Member Professor Alp Sehirlioglu 30 June 2017 *We also certify that written approval has been obtained for any proprietary material contained therein. Table of Contents 1. Acknowledgements ................................................................................................... 11 2. Abstract ...................................................................................................................... 12 3. Introduction ............................................................................................................... 13 1. Technological Demand for New Magnetic Core Material ................................................. 13 2. Magnetic Material and Properties ..................................................................................... 14 2.1: Inductor Magnetic Core Properties ................................................................................. 14 2.2: Coercivity
    [Show full text]
  • Magnetic Materials: Soft Magnets
    Magnetic Materials: Soft Magnets Soft magnetic materials are those materials that are easily magnetised and demagnetised. They typically have intrinsic coercivity less than 1000 Am-1. They are used primarily to enhance and/or channel the flux produced by an electric current. The main parameter, often used as a figure of merit for soft magnetic materials, is the relative permeability (µr, where µr = B/ µoH), which is a measure of how readily the material responds to the applied magnetic field. The other main parameters of interest are the coercivity, the saturation magnetisation and the electrical conductivity. The types of applications for soft magnetic materials fall into two main categories: AC and DC. In DC applications the material is magnetised in order to perform an operation and then demagnetised at the conclusion of the operation, e.g. an electromagnet on a crane at a scrap yard will be switched on to attract the scrap steel and then switched off to drop the steel. In AC applications the material will be continuously cycled from being magnetised in one direction to the other, throughout the period of operation, e.g. a power supply transformer. A high permeability will be desirable for each type of application but the significance of the other properties varies. For DC applications the main consideration for material selection is most likely to be the permeability. This would be the case, for example, in shielding applications where the flux must be channelled through the material. Where the material is used to generate a magnetic field or to create a force then the saturation magnetisation may also be significant.
    [Show full text]
  • Nonlinear and Hysteretic Magnetomechanical Model for Magnetostrictive Transducers Marcelo Jorge Dapino Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1999 Nonlinear and hysteretic magnetomechanical model for magnetostrictive transducers Marcelo Jorge Dapino Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Electromagnetics and Photonics Commons, Mechanical Engineering Commons, and the Physics Commons Recommended Citation Dapino, Marcelo Jorge, "Nonlinear and hysteretic magnetomechanical model for magnetostrictive transducers " (1999). Retrospective Theses and Dissertations. 12657. https://lib.dr.iastate.edu/rtd/12657 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-harKl comer and continuing from left to right in equal sections with small overlaps.
    [Show full text]
  • Beyond a Phenomenological Description of Magnetostriction
    ARTICLE DOI: 10.1038/s41467-017-02730-7 OPEN Beyond a phenomenological description of magnetostriction A.H. Reid et al.# Magnetostriction, the strain induced by a change in magnetization, is a universal effect in magnetic materials. Owing to the difficulty in unraveling its microscopic origin, it has been largely treated phenomenologically. Here, we show how the source of magnetostriction—the — 1234567890():,; underlying magnetoelastic stress can be separated in the time domain, opening the door for an atomistic understanding. X-ray and electron diffraction are used to separate the sub- picosecond spin and lattice responses of FePt nanoparticles. Following excitation with a 50-fs laser pulse, time-resolved X-ray diffraction demonstrates that magnetic order is lost within the nanoparticles with a time constant of 146 fs. Ultrafast electron diffraction reveals that this demagnetization is followed by an anisotropic, three-dimensional lattice motion. Analysis of the size, speed, and symmetry of the lattice motion, together with ab initio calculations accounting for the stresses due to electrons and phonons, allow us to reveal the magne- toelastic stress generated by demagnetization. Correspondence and requests for materials should be addressed to A.H.R. (email: [email protected]) or to H.A.Dür. (email: [email protected]). #A full list of authors and their affliations appears at the end of the paper. NATURE COMMUNICATIONS | (2018) 9:388 | DOI: 10.1038/s41467-017-02730-7 | www.nature.com/naturecommunications 1 ARTICLE NATURE COMMUNICATIONS | DOI: 10.1038/s41467-017-02730-7 – he functional properties of materials often depend on the substrates23 25. Our use of unconstrained FePt single-crystal detailed and subtle interplay of electronic, spin and lattice nanoparticles allows us to study the full three-dimensional lattice T 1–16 degrees of freedom .
    [Show full text]
  • Measuring the Inverse Magnetostrictive Effect in a Thin Film Using a Modified Vibrating Sample Magnetometer
    Measuring the inverse magnetostrictive effect in a thin film using a modified vibrating sample magnetometer Buford, B., Dhagat, P., & Jander, A. (2014). Measuring the inverse magnetostrictive effect in a thin film using a modified vibrating sample magnetometer. Journal of Applied Physics, 115(17), 17E309. doi:10.1063/1.4863492 10.1063/1.4863492 American Institute of Physics Publishing Version of Record http://cdss.library.oregonstate.edu/sa-termsofuse JOURNAL OF APPLIED PHYSICS 115, 17E309 (2014) Measuring the inverse magnetostrictive effect in a thin film using a modified vibrating sample magnetometer Benjamin Buford, Pallavi Dhagat, and Albrecht Jandera) Oregon State University, Corvallis, Oregon 97331, USA (Presented 8 November 2013; received 23 September 2013; accepted 30 October 2013; published online 30 January 2014) A method for measuring the magnetostriction of thin films using a vibrating sample magnetometer is described. We describe the design of a custom sample holder to apply an adjustable bending stress to the sample during measurement and observe the resulting change in the M-H loop. VC 2014 AIP Publishing LLC.[http://dx.doi.org/10.1063/1.4863492] I. INTRODUCTION II. METHODS Magnetostrictive materials, which change shape when A sample holder was constructed to apply a known placed in a magnetic field, are useful in mechanical actuator bending stress to the sample substrate during measurement. applications.1 Characterization of the magnetostrictive effect Key features of the design include light weight and axial typically consists of applying a magnetic field and measuring symmetry to avoid introducing lateral vibrations of the either the change in dimension of a bulk sample or meas- vibrating rod.
    [Show full text]
  • A Magnetoelastic Model for Villari-Effect Magnetostrictive Sensors
    A MAGNETOELASTIC MODEL FOR VILLARI-EFFECT MAGNETOSTRICTIVE SENSORS Marcelo J. Dapino¤ Department of Mechanical Engineering The Ohio State University 206 West 18th Avenue 2091 Robinson Lab Columbus, OH 43210 E-mail: [email protected] Ph.: (614) 688-3689 Fax: (614) 292-3163 Ralph C. Smith Department of Mathematics Center for Research in Scienti¯c Computation North Carolina State University Raleigh, NC 27695 Frederick T. Calkins Boeing Phantom Works Seattle, WA 98136 Alison B. Flatau Department of Aerospace Engineering and Engineering Mechanics Iowa State University Ames, IA 50011 ¤ Author to whom correspondence should be sent Key words: magnetostriction, magnetomechanical e®ect, Villari e®ect, magnetostrictive sensor, Terfenol-D ABSTRACT A magnetomechanical model for the design and control of Villari-e®ect magnetostrictive sensors is presented. The model quanti¯es the magnetization changes that a magnetostrictive material undergoes when subjected to a dc excitation ¯eld and variable stresses. The magnetic behavior is characterized by considering the Jiles-Atherton mean ¯eld theory for ferromagnetic hysteresis, which is constructed from a thermodynamic balance between the energy available for magnetic moment rotation and the energy lost as domain walls attach to and detach from pinning sites. The e®ect of stress on magnetization is quanti¯ed through a law of approach to the anhysteretic magnetization. Elastic properties of the sensor are incorporated by means of a wave equation that quanti¯es the strains and stresses arising in response to moment rotations. This yields a nonlinear PDE system for the strains, stresses and magnetization state of a magnetostrictive transducer as it drives or is driven by external loads.
    [Show full text]
  • An Online Tool to Visualize Magnetostriction
    sensors Letter MAELASviewer: An Online Tool to Visualize Magnetostriction Pablo Nieves * , Sergiu Arapan , Andrzej Piotr K ˛adzielawa and Dominik Legut IT4Innovations, VŠB—Technical University of Ostrava, 17. listopadu 2172/15, 70800 Ostrava-Poruba, Czech Republic; [email protected] (S.A.); [email protected] (A.P.K.); [email protected] (D.L.) * Correspondence: [email protected] Received: 27 September 2020; Accepted: 9 November 2020; Published: 11 November 2020 Abstract: The design of new materials for technological applications is increasingly being assisted by online computational tools that facilitate the study of their properties. In this work, based on modern web application frameworks, the online app MAELASviewer has been developed to visualize and analyze magnetostriction via a user-friendly interactive graphical interface. The features and technical details of this new tool are described in detail. Among other applications, it could potentially be used for the design of magnetostrictive materials for sensors and actuators. Keywords: magnetostriction; magnetoelastic effects; graphical user interface; web application; visualization 1. Introduction Magnetostriction is a physical phenomenon in which the process of magnetization induces a change in the shape or dimension of a magnetic material. These materials have the advantage that their magnetostrictive properties do not degrade over time as is the case for some poled piezoelectric materials, in addition to their good performance in terms of strains, forces, energy densities, and coupling coefficients [1]. As a result, magnetostrictive materials are widely used in many technological applications like sensors (torque sensors, motion and position sensors, force and stress sensors) and actuators (sonar transducers, linear motors, rotational motors, and hybrid magnetostrictive/piezoelectric devices) where a high magnetostriction is required [2–4].
    [Show full text]
  • Study of Effective Methods of Characterisation of Magnetostriction and Its Fundamental Effect on Transformer Core Noise
    STUDY OF EFFECTIVE METHODS OF CHARACTERISATION OF MAGNETOSTRICTION AND ITS FUNDAMENTAL EFFECT ON TRANSFORMER CORE NOISE PhD thesis Shervin Tabrizi A thesis submitted to the Cardiff University in candidature for the degree of Doctor of Philosophy December 2013 Wolfson Centre for Magnetics Cardiff School of Engineering Cardiff University Wales, United Kingdom i Abstract Magnetostriction of core laminations is one of the main sources of transformer acoustic noise. The magnetostriction of grain oriented silicon steel is extremely sensitive to applied compressive stress. A measurement system using piezoelectric accelerometers has been designed and built. This was optimized for magnetostriction measurements under stress within the range of 10 MPa to -10 MPa on large as-cut sheets. This system was used for characterization of wide range of grain-oriented grades. Laboratories around the world are using many different methods of measurement of the magnetostrictive properties of electrical steel. In response to this level of interest, an international round robin exercise on magnetostriction measurement has been carried out and eight different magnetostriction-measuring systems have been compared. Results show a reasonable correlation between the different methods. In this study the influence of factors such as the domain refinement process, curvature, and geometry on the magnetostriction of 3% grain oriented silicon steel were investigated. The study shows that both laser scribing and mechanical scribing have a similar effect on the sample’s domain structure and would cause an increase in magnetostriction. A proposed domain model was used successfully to estimate the effect of scribing on magnetostriction. Correlation between magnetostriction of 3% grain oriented silicon steel with transformer vibration was investigated.
    [Show full text]