Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Schiepp, Thomas
Languages: English
Types: Doctoral thesis
Subjects: TK, QA75
The systems/products and their design processes have become more and more complicated due to the fact that their requirements in terms of function, durability, reliability and energy efficiency have been increased significantly and that their leading time has to be short and their materials cost has to be low. To meet these requirements, individual parts and subsystems have to offer increased functionality and efficiency themselves. It has been found that smart materials, such as piezo ceramics or various shape memory alloys as well as less known dielectric elastomers or magnetic shape memory alloys, offer ideal preconditions to fulfil such requirements. Among the various shape memory alloys, the Magnetic Shape Memory (MSM) alloy is a kind of smart material that can elongate and contract in a magnetic field. Based on the MSM alloy a new type of smart electromagnetic actuators have been designed and developed. This kind of actuator exhibits the features above. Typically, the MSM material is a monocrystalline Ni-Mn-Ga alloy, which has the ability to change its size or shape very fast and many million times repeatedly. State-of-the-art alloys are able to achieve a magnetic field induced strain of up to 12%. The magneto-mechanical characteristic of MSM alloys is being constantly improved. However, as far as the author is aware, there are no efficient and commercially available tools for engineers to design MSM-based actuators. To achieve this, simulation tools for design are indispensable. This thesis is dedicated to this task.\ud \ud In this PhD thesis, new design and simulation techniques for MSM-based actuators have been studied. In particular, three simulation methods have been proposed. These three methods extend standard magneto-static FEM simulation techniques by taking into account the magneto-mechanical coupling and the magnetic anisotropy of the MSM materials. They differ in terms of the necessary a priori alloy characterisation (i.e., measurement effort), computational complexity and consequent computing time. The magneto-mechanical characteristics of the MSM material are a necessary and fundamental ingredient for this type of simulation. However, the characterisation of the MSM materials is a very challenging task and requires specific modifications to standard measurement approaches. So, in this thesis, some specific measurement methods of the magneto-mechanical characteristics of the MSM materials have been proposed, designed and developed. It is described how existing measurement instruments can be modified to measure the unique magneto-mechanical characteristics of MSM, so they are applicable and with practical values. Various tests have been carried out to validate the new methods and the necessary characterisations of the properties of MSM materials have been performed, such as the measurement of the permeability of MSM under a defined stress during elongation. The new measurement results have been analysed and the findings have been used to design and develop the simulation methods. The three simulation methods can be used to predict and optimise the current-elongation behaviour of an MSM element under the load of a mechanical stress while excited by a magnetic field. Extensive experiments have been carried out to validate these three simulation methods. The results show that the three methods are relatively simple but, at the same time, very effective means to model, predict and optimise the properties of an MSM actuator using finite element tools. In addition, the experiment results have also shown that the simulation methods can be used to gain some deep insights into the magneto-mechanical interaction between the MSM element and the electromagnetic actuator. In this thesis an evolutionary algorithm which works together with the simulation methods has been developed to achieve individual optimised solutions in very short times.\ud \ud In summary, from the experiment results, it has been found that the measurements and simulation methods proposed and developed in this thesis; enable designers to perform simulations for a high-quality actuator design based on the magneto-mechanical properties of MSM alloys. This is the first time that a MSM can be characterised for simulation purposes in a fast and precise way to predict MSM and electromagnetic actuator interactions and identify and optimise the design parameters of such actuators.\ud However, these simulation methods are strongly dependent on the measurement of the magneto-mechanical characteristics of magnetic shape memory alloys, whose precision can be further improved. To reach commercial success as well higher precision in the simulation prediction, further achievements in the field of material science (e.g. smoothness of mechanical curves) are also necessary.
  • The results below are discovered through our pilot algorithms. Let us know how we are doing!

    • Claeys, P., & Vogel, A. (2006). Patent No. DE 10 2004 056 279 A1. Germany.
    • Hunt, F. (1947, July). A Survey of Magnetostriction Transducer Research at the Harvard Underwater Sound Laboratory 1941-1945. The Journal of the acoustical society of America, Volume 19, Number 4 , p. 725.
    • James, R., & Wuttig, M. (1998). Magnetostriction of martensite. Philosophical Magazine A, Vol. 77 No. 5 , pp. 1273-1299.
    • Janocha, H. (2013). Unkonventionelle Aktoren. München: Oldenbourg Verlag.
    • Jiles, D. (1998). Introduction to Magnetism and Magnetic Materials, 2nd Edition. London & New York: Chapman and Hall.
    • Jiles, D., & Devine, M. (1994, November). Recent developments in modeling of the stress derivative of magnetization in Recent developments in modeling of the stress derivative of magnetization in ferromagnetic materials. Journal of Applied Physics, Vol. 76, No. 10 , pp. pp. 7015-7017.
    • Joule, J. (1847). On the Effects of Magnetism upon the Dimensions of Iron and Steel Bars. The London, Edinburgh and Dublin philosophical magazine and journal of science (Taylor & Francis) , pp. 225-241.
    • Kallenbach, E., Eick, R., Quendt, P., Ströhla, T., Feindt, K., Kallenbach, M., et al. (2012).
    • Karaman, I., & Lagoudas, C. (2006, January 29). TEES Final Progress Report to ARO on the project, “Magnetic Shape Memory Alloys with High Actuation Forces”. Texas, USA.
    • Keilig, R. (2007). Doctoral Dissertation: Entwurf von schnellschaltenden (hochdynamischen) neutralen Elektromagnetsystemen. Illmenau, Germany: Universität Illmenau.
    • Kiang, J., & Tong, L. (2009, Dezember 8). Nonlinear magneto-mechanical finite element analysis of Ni-Mn-Ga single crystals. Smart Materials and Structures, Volume 19, Number 1 , p. 015017.
    • Laufenberg, M., & Schiepp, T. (2014b). Patent No. WO 2014/019738. Worldwide.
    • Lee, T., & Aksay, I. (2001, May 03). Hierarchical Structure-Ferroelectricity Relationships of Barium Titanate Particles. Crystal Growth & Design, Vol.1, No.5 , pp. 401-419.
    • Liebermann, H., & Graham Jr., C. (1977, July). Plastic and magnetoplastic deformation of Dy single crystals. Acta Metallurgica, Volume 27, Issue 7 , pp. 715-720.
    • Likhachev, A., & Ullakko, K. (2000). Quantitaive Model of Large Magnetostrain Effect in Ferronagnetic Shape Memory Alloys. Physics Letters A, Vol. 275 No. 1-2 , pp. 142-151.
    • Ullakko, K., Huang, J., Kantner, C., & O'Handley, R. (1996, September). Large magnetic-fieldinduced strains in Ni MnGa single crystals. Appl.Phys. Lett., Vol. 69, No. 13 , pp. 1966-1968.
    • Ullakko, K., Huang, J., Kokorin, V., & O'Handley, R. (1997). Magnetically Controlled Shape Memory Effect in Ni2MnGa Intermetallics. Scripta Materialia, Vol.36 , pp. 1133-1138.
    • Ullakko, K., Jakovenko, P., & Gavriljuk, V. (1996, August). High-strength shape memory steels alloyed with nitrogen. Scripta Materialia, Volume 35, Issue 4 , pp. 473-476.
    • von Hippel, A. (1950, July 1). Ferroelectricity, Domain Structure, and Phase Transitions of Barium Titanate. Reviews of Modern Physics, Volume 22, Issue 3, , pp. 221-237.
    • Watkins, F. (1833, January 1). On the Magnetic Powers of Soft Iron. Philosophical Transactions of the Royal Society of London , pp. 333-342.
  • No related research data.
  • No similar publications.

Share - Bookmark

Cite this article