Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 9 of 9 for “"Pseudoelasticity"”.
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Using shape memory alloy as dampers : design methodology
… to model the stress-strain curve of SMA during pseudoelasticity. Simulation is carried out to study the dynamic response of such a system under harmonic loading. Three kinds of systems were examined, in order of increasing complexity: the friction damper system, the hysteretic damper system, and …
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Mechanics of Phase Transformation in NiTi Shape Memory Alloys at The Atomistic Scale
… SMAs relies on either the shape memory effect or pseudoelasticity, the two distinctive properties of SMAs. Both these unique properties are based on the inherent capability of SMAs to have two stable lattice structures at different stress or temperature conditions, and the ability of changing …
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Constitutive modeling and finite element analysis of the dynamic behavior of shape memory alloys
… 3-D macromechanical model of localized unstable pseudoelasticity. An important feature of this model is the reorientation of the transformation strain tensor with changes in stress tensor. Unlike previous modeling efforts, the present model can also capture the propagation of localized …
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Critical stresses for twinning, slip and transformation in shape memory alloys: modeling and experiments
… alloys with D03 austenite structures exhibit pseudoelasticity due to reversible slips and twinning-detwinning mechanisms upon loading and unloading. The advantage of these alloys compared to transforming shape memory alloys is the potentially large pseudoelastic temperature range. Reversible …
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A Novel Shape Memory Behavior of Single-crystalline Metal Nanowires
… transformation. Therefore, nanowires show either pseudoelasticity or shape memory effect depending on whether the transformation is induced by unloading or heating. It is also found that not all FCC nanowires show shape memory behavior. Only FCC metals with higher tendency for twinning (such as …
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Characterization of Stoichiometric and Aging Effects on NiTiHf High Temperature Shape Memory Alloys
… temperature and the temperature range over which pseudoelasticity versus austenite plasticity was dominant was significantly affected by aging. In addition, the aging effects were analyzed by several transmission electron microscopy techniques. Detailed STEM characterization has revealed that the …
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On the thermomechanics of localizing pseudoelastic transformations in NiTi materials and structures
… are recovered during the reverse transformation (pseudoelasticity). In a structure, the transformations occur inhomogeneously with two deformation regimes coexisting, separated by sharp fronts. Moreover, latent heat is released/absorbed at the fronts causing temperature gradients which can affect …
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Dislocation slip and twinning stress in shape memory alloys- theory and experiments
… plasticity, which results in affecting their pseudoelasticity and shape memory performance. Precisely determining Peierls stress in dislocation slip and critical twin nucleation stress in twinning is essential to facilitate the design of new transforming alloys. This thesis presents an …
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Advanced experimental measurements of heterogeneous strain and temperature change in metals
This work investigates elevated temperature deformation in the nickel-based superalloy Haynes 230 and elastocaloric cooling in shape memory alloys. Three loading conditions were examined in the elevated temperature portion: fatigue crack growth, creep, and tension. Measurements were made on varying …