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An energy-relaxation-based framework for the modeling of magnetic shape memory alloys—Simulation of three-dimensional effects under homogeneous loading conditions

Bartel, Thorsten ; Kiefer, Bjoern and Menzel, Andreas LU (2021) In International Journal of Solids and Structures 208-209. p.221-234
Abstract

It is known from experimental findings that three-dimensional effects can have a strong influence on magnetic shape memory behavior. Such phenomena are, however, often neglected in MSMA constitutive models, as they only become meaningful under complex loading conditions. The extensions of our original modeling framework, cf. Bartel et al. (2020), to include 3D-effects is threefold: (i) vector-valued microstructural variables are now elements in R3, i.e. no longer parameterizable in polar coordinates, (ii) a third tetragonal martensite variant may form/vanish by switching from/back into both other variants, and (iii) a more general and robust algorithmic treatment is necessary. The latter includes the implementation of a... (More)

It is known from experimental findings that three-dimensional effects can have a strong influence on magnetic shape memory behavior. Such phenomena are, however, often neglected in MSMA constitutive models, as they only become meaningful under complex loading conditions. The extensions of our original modeling framework, cf. Bartel et al. (2020), to include 3D-effects is threefold: (i) vector-valued microstructural variables are now elements in R3, i.e. no longer parameterizable in polar coordinates, (ii) a third tetragonal martensite variant may form/vanish by switching from/back into both other variants, and (iii) a more general and robust algorithmic treatment is necessary. The latter includes the implementation of a staggered Augmented Lagrangian scheme to handle the now much larger and numerically more advanced sets of equality and inequality constraints. In this context, two extended model formulations are presented. The first considers a first-order, two-variant laminate approach (rank-one convexification), in which domain magnetizations, interface orientations etc. are now three-dimensional vectors. The second model is based on a convexification approach, for which the incorporation of the third martensitic variant is quite natural. Numerical examples are investigated to test the generalized modeling framework. Firstly, it is confirmed that both extended models recover the solution of the previously established two-dimensional model for a simple loading case. Secondly, response predictions for more complex loading scenarios (non-proportional bi-axial stresses, orthogonal magnetic field), motivated by experiments, are investigated. It is found that capturing the formation, elimination and mutual interaction of all martensitic variants as well as general three-dimensional magnetization vector orientations is of key importance under these conditions. The extended convexification model and modified algorithmic formulation are shown to reliably handle even such general cases.

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author
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type
Contribution to journal
publication status
published
subject
keywords
Constitutive modeling, Magnetic shape memory alloys, Magnetomechanical coupling, Micromagnetics, Micromechanics, Three-dimensional model formulation
in
International Journal of Solids and Structures
volume
208-209
pages
14 pages
publisher
Elsevier
external identifiers
  • scopus:85097167078
ISSN
0020-7683
DOI
10.1016/j.ijsolstr.2020.10.024
language
English
LU publication?
yes
id
15ca0e14-83f8-4618-af1c-6972c958ad92
date added to LUP
2020-12-15 05:23:03
date last changed
2022-04-26 22:31:38
@article{15ca0e14-83f8-4618-af1c-6972c958ad92,
  abstract     = {{<p>It is known from experimental findings that three-dimensional effects can have a strong influence on magnetic shape memory behavior. Such phenomena are, however, often neglected in MSMA constitutive models, as they only become meaningful under complex loading conditions. The extensions of our original modeling framework, cf. Bartel et al. (2020), to include 3D-effects is threefold: (i) vector-valued microstructural variables are now elements in R<sup>3</sup>, i.e. no longer parameterizable in polar coordinates, (ii) a third tetragonal martensite variant may form/vanish by switching from/back into both other variants, and (iii) a more general and robust algorithmic treatment is necessary. The latter includes the implementation of a staggered Augmented Lagrangian scheme to handle the now much larger and numerically more advanced sets of equality and inequality constraints. In this context, two extended model formulations are presented. The first considers a first-order, two-variant laminate approach (rank-one convexification), in which domain magnetizations, interface orientations etc. are now three-dimensional vectors. The second model is based on a convexification approach, for which the incorporation of the third martensitic variant is quite natural. Numerical examples are investigated to test the generalized modeling framework. Firstly, it is confirmed that both extended models recover the solution of the previously established two-dimensional model for a simple loading case. Secondly, response predictions for more complex loading scenarios (non-proportional bi-axial stresses, orthogonal magnetic field), motivated by experiments, are investigated. It is found that capturing the formation, elimination and mutual interaction of all martensitic variants as well as general three-dimensional magnetization vector orientations is of key importance under these conditions. The extended convexification model and modified algorithmic formulation are shown to reliably handle even such general cases.</p>}},
  author       = {{Bartel, Thorsten and Kiefer, Bjoern and Menzel, Andreas}},
  issn         = {{0020-7683}},
  keywords     = {{Constitutive modeling; Magnetic shape memory alloys; Magnetomechanical coupling; Micromagnetics; Micromechanics; Three-dimensional model formulation}},
  language     = {{eng}},
  pages        = {{221--234}},
  publisher    = {{Elsevier}},
  series       = {{International Journal of Solids and Structures}},
  title        = {{An energy-relaxation-based framework for the modeling of magnetic shape memory alloys—Simulation of three-dimensional effects under homogeneous loading conditions}},
  url          = {{http://dx.doi.org/10.1016/j.ijsolstr.2020.10.024}},
  doi          = {{10.1016/j.ijsolstr.2020.10.024}},
  volume       = {{208-209}},
  year         = {{2021}},
}