A thermodynamics-based constitutive model is derived which predicts the nonlinear
strain and magnetization response that magnetic shape memory alloys (MSMAs) exhibit
when subjected to mechanical and magnetic loads. The model development
is conducted on the basis of an extended thermo-magneto-mechanical framework.
A novel free energy function for MSMAs is proposed, from which the constitutive
equations are derived in a thermodynamically-consistent manner. The nonlinear and
hysteretic nature of the macroscopic material behavior is captured through the evolution
of internal state variables which are motivated by the crystallographic and
magnetic microstructures of MSMAs. Model predictions are presented for different
relevant loading cases and analyzed in detail. Finally, magnetostatic boundary
value problems for MSMAs are considered and numerically solved using the finite
element method. For these computations the developed constitutive model provides
the nonlinear magnetic properties of the MSMA. The knowledge of the magnetic field
distribution in the computational domain as a function of the applied field, which
results from this magnetostatic analysis, is useful for the proper interpretation of
experimental results as well as the design of experiments and applications.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/4712 |
| Date | 25 April 2007 |
| Creators | Kiefer, Bjoern |
| Contributors | Lagoudas, Dimitris C. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Dissertation, text |
| Format | 3317052 bytes, electronic, application/pdf, born digital |
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