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Contributions to Books:

M. Aurada, J. Melenk, D. Praetorius:
"Mixed conforming elements for the large-body limit in micromagnetics (MATHMOD 09)";
in: "ASC Report 49/2009", issued by: Institute for Analysis and Scientific Computing; Vienna University of Technology, Wien, 2009, ISBN: 978-3-902627-02-5.



English abstract:
The macroscopic behavior of stationary micromagnetic phenomena can be
modeled by a relaxed version of the Landau-Lifshitz minimization problem first introduced
by DeSimone in 1993, [5], where the magnetic potential u is linked to the
magnetization m through the magnetostatic Maxwell equation. In the case of large and
soft magnets
, one neglects the exchange energy and convexifies the remaining energy
densities. In our discretization we enforce the pointwise side constraint |m| ≤ 1 by a
penalization strategy and we replace the entire space Rd in the energy functional E and
in the potential equation by a bounded Lipschitz domain b
containing
. Since conforming
elements appear to be unstable for the pure Galerkin discretization (cf. [3]) we
append to the Galerkin discretization a consistent stabilization term. We reformulate
the minimization problem in terms of the augmented Lagrangean, which leads us to a
so called saddle-point formulation for the corresponding Euler-Lagrange equations.
In this paper we discuss the well-posedness of the discrete problem and the a priori
error analysis. Furthermore we introduce a residual-based a posteriori error estimator
and comment on adaptive strategies


Electronic version of the publication:
http://www.asc.tuwien.ac.at/preprint/2009/asc49x2009.pdf


Created from the Publication Database of the Vienna University of Technology.