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Dr.-Ing. Rainer Heinen

  • ehem. Wissenschaftlicher Mitarbeiter
  • Lehrstuhl für Allgemeine Mechanik
  • Institut für Computational Engineering
  • Fakultät für Bau- und Umwelt-
    ingenieurwissenschaften
  • Raum IA 3/134
  • Fon +49 (0)234 /32-26000
  • Fax +49 (0)234 /32-26000
  • E-Mail: Rainer.Heinen@rub.de

Lehre

  • Lehrauftrag im Studiengang Computaional Engineering

Forschung

  • Wissenschaftliche Bearbeitung des Projektes
    Mikromechanische Modellierung von Formgedächtnismaterialien
    Sonderforschungsbereich 459 Formgedächtnistechnik, Projekt A9, der Deutschen Forschungsgemeinschaft

Kurzer Lebenslauf

1999
Abitur in Werne a. d. Lippe
1999-2000
Zivildienst in Lünen
2000-2004
Studium Maschinenbau an der Ruhr-Uni Bochum, Auslandssemester an der Escuela Superior de Ingenieros, Sevilla, und an der University of California, Berkeley
2001-2002
Studentische Hilfskraft, Lehrstuhl für Maschinenelemente und Fördertechnik, Ruhr-Uni Bochum
2003-2004
Studentische Hilfskraft, Lehrstuhl für Allgemeine Mechanik, Ruhr-Uni Bochum
2005-2007
Wissenschaftlicher Mitarbeiter

Publikationen

Heinen, R.; Hackl, K.; Windl, W.; Wagner, M.F.X.
Microstructural evolution during multiaxial deformation of pseudoelastic NiTi studied by first-principles-based micromechanical modeling,
Acta Materialia, Vol. 57(13), pp. 3856-3867, (2009).

[BibTeX] [DOI]
BibTeX: 
@article{Heinen2009,
  author = {Heinen, Rainer and Hackl, Klaus and Windl, W. and Wagner, M. F. -X.},
  title = {Microstructural evolution during multiaxial deformation of pseudoelastic NiTi studied by first-principles-based micromechanical modeling},
  journal = {Acta Materialia},
  year = {2009},
  volume = {57},
  number = {13},
  pages = {3856-3867},
  doi = {http://dx.doi.org/10.1016/j.actamat.2009.04.036}
}
Hackl, K.; Heinen, R.
An upper bound to the free energy of n-variant polycrystalline shape memory alloys,
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, Vol. 56(9), pp. 2832-2843, (2008).

[BibTeX]
BibTeX: 
@article{Hackl2008a,
  author = {Hackl, Klaus and Heinen, Rainer},
  title = {An upper bound to the free energy of n-variant polycrystalline shape memory alloys},
  journal = {JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS},
  year = {2008},
  volume = {56},
  number = {9},
  pages = {2832-2843}
}
Hackl, K.; Heinen, R.
A micromechanical model for pretextured polycrystalline shape-memory alloys including elastic anisotropy,
Continuum Mechanics and Thermodynamics, Vol. 19, pp. 8, (2008).

[Abstract] [BibTeX] [DOI]
Abstract: We present a micromechanical model for polycrystalline shape-memory alloys which is capable of reproducing important aspects of the material behavior such as pseudoelasticity, pseudoplasticity, tension–compression asymmetry and the influence of texture inhomogeneities which may occur from the production process of components or specimens. Our model is based on the optimization of the material’s free energy density and uses a dissipation ansatz which is homogeneous of first order. Considering the full anisotropic material properties of both the austenite and the martensite phase, we compute the evolution of the orientation distributions of austenite and martensite as internal variables of our model.
BibTeX: 
@article{Hackl2008b,
  author = {Hackl, Klaus and Heinen, Rainer},
  title = {A micromechanical model for pretextured polycrystalline shape-memory alloys including elastic anisotropy},
  journal = {Continuum Mechanics and Thermodynamics},
  year = {2008},
  volume = {19},
  pages = {8},
  doi = {http://dx.doi.org/10.1007/s00161-008-0067-z}
}
Hackl, K.; Heinen, R.; Schmahl, W.W.; Hasan, M.
Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions,
Materials Science and Engineering A, Vol. 481(Sp. Iss. SI), pp. 347-350, (2008).

[BibTeX]
BibTeX: 
@article{Hackl2008c,
  author = {Hackl, Klaus and Heinen, Rainer and Schmahl, W. W. and Hasan, M.},
  title = {Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions},
  journal = {Materials Science and Engineering A},
  year = {2008},
  volume = {481},
  number = {Sp. Iss. SI},
  pages = {347-350}
}
Hasan, M.; Schmahl, W.W.; Hackl, K.; Heinen, R.; Frenzel, J.; Gollerthan, S.; Eggeler, G.; Khalil-Allafi, J.; Baruj, A.
Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys under uniaxial load,
Materials Science and Engineering A, Vol. 481(Sp. Iss. SI), pp. 414-419, (2008).

[BibTeX]
BibTeX: 
@article{Hasan2008,
  author = {Hasan, M. and Schmahl, W. W. and Hackl, Klaus and Heinen, Rainer and Frenzel, J. and Gollerthan, S. and Eggeler, G. and Khalil-Allafi, J. and Baruj, A.},
  title = {Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys under uniaxial load},
  journal = {Materials Science and Engineering A},
  year = {2008},
  volume = {481},
  number = {Sp. Iss. SI},
  pages = {414-419}
}
Heinen, R.; Hoppe, U.; Hackl, K.
Prediction of microstructural patterns in monocrystalline shape memory alloys using global energy minimization,
Materials Science and Engineering A, Vol. 481(Sp. Iss. SI), pp. 362-365, (2008).

[Abstract] [BibTeX] [DOI]
Abstract: A frequent observation in materials showing martensitic phase transformations is the formation of twins. Considering monocrystalline shape memory alloys, analytical results are known stating which martensitic variants are capable of forming an unstrained interface with each other. Based on these results, an estimate of the elastic energy of the material is formulated. By global optimization, microstructural parameters such as the orientation and the composition of the martensitic twins are determined.
BibTeX: 
@article{Heinen2008,
  author = {Heinen, Rainer and Hoppe, Ulrich and Hackl, Klaus},
  title = {Prediction of microstructural patterns in monocrystalline shape memory alloys using global energy minimization},
  journal = {Materials Science and Engineering A},
  year = {2008},
  volume = {481},
  number = {Sp. Iss. SI},
  pages = {362-365},
  doi = {http://dx.doi.org/10.1016/j.msea.2006.11.175}
}
Schmahl, W.W.; Hackl, K.; Heinen, R.; Frenzel, J.; Hasan, M.
Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys $,
Materials Science and Engineering A, (2008).

[BibTeX] [URL]
BibTeX: 
@article{Schmahl2008,
  author = {Schmahl, W. W. and Hackl, Klaus and Heinen, Rainer and Frenzel, J. and Hasan, M.},
  title = {Hard X-ray studies of stress-induced phase transformations of superelastic NiTi shape memory alloys $},
  journal = {Materials Science and Engineering A},
  year = {2008},
  url = {http://linkinghub.elsevier.com/retrieve/pii/S0921509307012531}
}
Govindjee, S.; Hackl, K.; Heinen, R.
An upper bound to the free energy of mixing by twin-compatible lamination for n-variant martensitic phase transformations,
Continuum Mechanics and Thermodynamics, Vol. 18(7-8), pp. 443-453, (2007).

[Abstract] [BibTeX] [DOI]
Abstract: Modeling the energetic behavior of martensitic (phase transforming) materials usually leads to non quasiconvex energy formulations. For this reason, researchers often employ quasiconvex relaxation methods to improve the character of the formulation. Unfortunately, explicit expressions for the relaxed free energy density for multi-variant martensitic materials are typically not available. Thus, some researchers have employed a Reu?-like convex lower bound, which neglects compatibility constraints, as an estimate on the free energy of mixing. To be confident with such a technique, one needs a measure of the quality of the lower bound. In this paper, we seek such a measure by comparing the Reu?-like lower bound to an upper bound. The upper bound is constructed upon assumptions on the type of microstructures that form in such alloys. In particular, we consider lamination type microstructures which form by temperature- or stress-induced transformation in monoclinic and orthorhombic Copper-based alloys with cubic austenitic symmetry. Our results display a striking congruence of upper and lower bounds in the most relevant cases.
BibTeX: 
@article{Govindjee2007,
  author = {Govindjee, S. and Hackl, Klaus and Heinen, Rainer},
  title = {An upper bound to the free energy of mixing by twin-compatible lamination for n-variant martensitic phase transformations},
  journal = {Continuum Mechanics and Thermodynamics},
  year = {2007},
  volume = {18},
  number = {7-8},
  pages = {443-453},
  doi = {http://dx.doi.org/10.1007/s00161-006-0038-1}
}
Heinen, R.; Hackl, K.
On the calculation of energy-minimizing phase fractions in shape memory alloys,
Computer Methods in Applied Mechanics and Engineering, Vol. 196(21-24), pp. 2401-2412, (2007).

[BibTeX]
BibTeX: 
@article{Heinen2007,
  author = {Heinen, Rainer and Hackl, Klaus},
  title = {On the calculation of energy-minimizing phase fractions in shape memory alloys},
  journal = {Computer Methods in Applied Mechanics and Engineering},
  year = {2007},
  volume = {196},
  number = {21-24},
  pages = {2401-2412}
}
Heinen, R.; Hackl, K.; Kotucha, G.; Bartel, T.
A Lamination Upper Bound to the Free Energy of Shape Memory Alloys,
Proceedings in Applied Mathematics and Mechanics (PAMM), Vol. 6(1), pp. 481-482, (2006).

[Abstract] [BibTeX] [DOI]
Abstract: Modeling the energetic behavior of materials showing martensitic phase transformations usually leads to non-convex energy formulations. In a variety of models based on quasi-convex analysis, the Reuß lower bound, which neglects the compatibility constraint for the deformation fluctuations, is used as an estimate for the so-called energy of mixing.

We present an upper bound that is on the one hand based on the lamination mixture formula, which gives an estimate of the free energy of two-variant materials and is extended to a specialized n-variant case in our work. On the other hand, we rely on experimentally well established assumptions about the type of microstructure that forms in such alloys. More precisely, we restrict the set of physically admissible microstructures to the subset of second order laminated microstructres consisting of austenite and twinned martensites. We further refine our upper bound by taking into account the notion of twin-compatibility.

For the physically relevant examples of 13- and 7-variant Cu-Al-Ni shape memory alloys, striking congruence is obtained in the comparison of the Reuß lower and our upper bound for fixed volume fractions. Furthermore, we show results of global minimization of the energy obtained by each bound over the volume fractions of the variants. Similarities and differences in the energy-minimizing volume fractions are discussed.
BibTeX: 
@article{Heinen2006,
  author = {Heinen, Rainer and Hackl, Klaus and Kotucha, Gregor and Bartel, Thorsten},
  title = {A Lamination Upper Bound to the Free Energy of Shape Memory Alloys},
  journal = {Proceedings in Applied Mathematics and Mechanics (PAMM)},
  year = {2006},
  volume = {6},
  number = {1},
  pages = {481-482},
  doi = {http://dx.doi.org/10.1002/pamm.200610221}
}

Sonstiges

In meiner Freizeit gehe ich gerne ins Kino, fahre Inline-Skates und bin im Segelverein Witten-Kemnade für die Erwachsenenausbildung verantwortlich.