Nonequilibrium thermodynamics of pseudoelasticity

We make use of a micromechanical model for polycrystalline shape memory alloys, whose main focus is the orientation distribution of the martensitic low symmetry variant. By energy minimization, the internal reorientation of martensite can be predicted. Hysteresis effects are included via the hypothesis that changes in the orientation distribution are connected to energy dissipation. From these considerations, we obtain evolution equations for the orientation distribution in terms of the thermomechanical driving forces. Comparing our model to results from synchrotron diffraction experiments, good agreement is found between experimentally observed and analytically predicted orientations of austenite and stressinduced martensite.

show abstract

“…A thermodynamical framework with a focus similar to this paper has been given in [6]. * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions

Hackl

Heinen

Schmahl

et al. 2008

Materials Science and Engineering: A

View full text Add to dashboard Cite

show abstract

“…A complex interior hysteresis loop was observed in uniaxial tensile tests in single crystalline shape memory alloys [47][48][49][50][51][52][53], and a similar phenomenon has been reported in martensite reorientation between two martensite lattice correspondence variants [34]. These interior hysteresis loops were given various names, such as internal elasticity, internal yield and internal recovery in the literature (for example figure 2 in [48], figures 1 and 4 in [49], figures 4, 5 and 8 in [50]). Considering an isothermal loading/unloading process as shown in figure 2, phase transformation starts at B upon loading.…”

Section: Introductionmentioning

confidence: 99%

“…Here z is the volume fraction of one phase. Similar formulae have been used for shape memory alloys [47][48][49][50][51]. Unfortunately, this simple closed-form solution is only for two-phase mixtures.…”

Section: Introductionmentioning

confidence: 99%

“…According to the experimental results in [50], the critical condition for starting a phase transformation is…”

Section: Transition Lawmentioning

confidence: 99%

“…Oblivion plays an important role in the formation of an interior hysteresis loop, which happens when an internal state crosses lines l 1 and l 2 in figure 2. Huo and Müller [50] concluded that the interior hysteresis loop is due to history-dependent pseudoelasticity, and the fraction of the last transformation state is remembered. Fedelich and Zanzotto [48] suggested choosing the fraction of martensite variant in the last transformation as an additional internal variable to describe these loops.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theory of phase transformation and reorientation in single crystalline shape memory alloys

Zhu¹,

Liang²,

Cai³

et al. 2008

Smart Mater. Struct.

View full text Add to dashboard Cite

A constitutive model, based on an (n + 1)-phase mixture of the Mori-Tanaka average theory, has been developed for stress-induced martensitic transformation and reorientation in single crystalline shape memory alloys. Volume fractions of different martensite lattice correspondence variants are chosen as internal variables to describe microstructural evolution. Macroscopic Gibbs free energy for the phase transformation is derived with thermodynamics principles and the ensemble average method of micro-mechanics. The critical condition and the evolution equation are proposed for both the phase transition and reorientation. This model can also simulate interior hysteresis loops during loading/unloading by switching the critical driving forces when an opposite transition takes place.

show abstract

Influence of Hardening and Inhomogeneity on Internal Loops in Pseudoelasticity

Kuczma

Mielke

2000

Z. angew. Math. Mech.

View full text Add to dashboard Cite

Nonequilibrium thermodynamics of pseudoelasticity

Cited by 174 publications

References 33 publications

Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions

Experimental verification of a micromechanical model for polycrystalline shape memory alloys in dependence of martensite orientation distributions

Theory of phase transformation and reorientation in single crystalline shape memory alloys

Influence of Hardening and Inhomogeneity on Internal Loops in Pseudoelasticity

Contact Info

Product

Resources

About