A fiber-progressive-engagement model to evaluate the composition, microstructure, and nonlinear pseudoelastic behavior of porcine arteries and decellularized derivatives

Owing to geometrical non-uniformity, geometrically graded shape memory alloy (SMA) structures by design have the ability to exhibit different and novel thermal and mechanical behaviors compared to geometrically uniform conventional SMAs. This paper reports a study of the pseudoelastic behavior of geometrically graded NiTi plates. This geometrical gradient creates partial stress gradient over stress-induced martensitic transformation, providing enlarged stress controlling interval for shape memory actuation. Finite element modeling framework has been established to predict the deformation behavior of such structures in tensile loading cycles, which was validated by experiments. The modeling results show that the transformation mostly propagates along the gradient direction as the loading level increases.

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Influence of Strain Rate on Pseudoelastic Behavior in TiNi Shape Memory Alloy.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.66.496 ◽

2000 ◽

Vol 66 (643) ◽

pp. 496-501

Author(s):

Yoshirou SHIMENO ◽

Hisaaki TOBUSHI ◽

Kazuyuki TAKATA ◽

S.P. GADAJ ◽

W.K. NOWACKI

Keyword(s):

Shape Memory Alloy ◽

Strain Rate ◽

Shape Memory ◽

Pseudoelastic Behavior

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Finite element analysis of pseudoelastic behavior of NiTi shape memory alloy with thin-wall tube under extension-torsion loading

Journal of Materials Science ◽

10.1007/s10853-006-1223-0 ◽

2007 ◽

Vol 42 (7) ◽

pp. 2443-2449 ◽

Cited By ~ 2

Author(s):

X. M. Wang ◽

M. Frotscher ◽

Y. F. Wang ◽

Z. F. Yue

Keyword(s):

Finite Element Analysis ◽

Finite Element ◽

Shape Memory Alloy ◽

Shape Memory ◽

Niti Shape Memory Alloy ◽

Thin Wall ◽

Element Analysis ◽

Pseudoelastic Behavior

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Pseudoelasticity of D03-Type Fe3Al and Fe3Ga-Based Alloys

MRS Proceedings ◽

10.1557/opl.2011.386 ◽

2011 ◽

Vol 1295 ◽

Cited By ~ 1

Author(s):

Hiroyuki Y. Yasuda ◽

Yukichi Umakoshi

Keyword(s):

Chemical Composition ◽

Martensitic Transformation ◽

Deformation Temperature ◽

Antiphase Boundary ◽

Dislocation Motion ◽

In Situ Observations ◽

Loading Axis ◽

Superpartial Dislocation ◽

Pseudoelastic Behavior

ABSTRACTThe pseudoelastic behavior of Fe3Al and Fe3Ga alloys with the D03 structure is reviewed. In general, pseudoelasticity of shape memory alloys is based on a thermoelastic martensitic transformation. However, pseudoelasticity regardless of the martensitic transformation is found to take place in D03-ordered Fe3Al and Fe3Ga alloys. For instance, a 1/4<111> superpartial dislocation in Fe3Al alloys moves independently dragging an antiphase boundary (APB). During unloading, the APB pulls back the superpartial to decrease its energy resulting in pseudoelasticity, which is called “APB pseudoelasticity”. Moreover, D03-type Fe3Ga alloys were found to demonstrate three types of pseudoelasticity based on the dislocation motion, twinning and martensitic transformation depending on the chemical composition, degree of D03 order, loading axis, stress sense and deformation temperature. The mechanism of the pseudoelasticities in the D03-type intermetallics is discussed based on some in situ observations. The effects of chemical composition, deformation temperature and crystal orientation on the pseudoelastic behaviors are also discussed.

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Biocompatibility and Mechanical Performance of Ni-Ti

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.1617 ◽

2007 ◽

Vol 534-536 ◽

pp. 1617-1620 ◽

Cited By ~ 1

Author(s):

J. Kim ◽

Y.C. Choi ◽

Hyoung Seop Kim ◽

Sun Ig Hong

Keyword(s):

Mechanical Performance ◽

Orthopedic Implants ◽

Apatite Formation ◽

Martensite Formation ◽

Biomimetic Apatite ◽

Macro Scale ◽

Apatite Deposition ◽

Cold Worked ◽

Strain Responses ◽

Pseudoelastic Behavior

Biomimetic apatite deposition behaviors and mechanical performance for as-rolled and annealed Ni-Ti plates were investigated. Apatite nucleation and growth on Ni-Ti in SBF (simulated body fluid) was not appreciably influenced by heat treatment. But, the apatite deposition rate increased slightly by NaOH surface treatment. The nodular apatite on the deposited layer is favored on a macro-scale since the surface energy of polycrystalline apatite particles can be reduced by forming nodules. The weight gain after apatite deposition for Ni-Ti (0.004 g/cm2) after 10 days were found to be smaller that that of NaOH treated Ti-6Al-4V, but it was comparable to that of non- NaOH-treated Ti-6Al-4V (0.004 g/cm2). The stress-strain responses of annealed Ni-Ti displayed the pseudoelastic behavior associated with stress-induced martensite formation with the transition stress for the martensite formation equal to 320 MPa. On the other hand the cold worked Ni-Ti displayed no appreciable pseudoelastic region and the yield stress was ~500MPa. A good biomimetic apatite formation and excellent mechanical performance of Ni-Ti suggests that Ni-Ti can be an excellent candidate material for orthopedic implants.

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