Determination of the elastic properties of randomly oriented shape memory alloy (SMA) discontinuous wires reinforced epoxy resin

Abstract Background: To explore the role of nickel-titanium(NiTi) shape memory alloy embracing fixator in determination of implantation angle of hip tumor prosthesis stem and analyze its efficacy. Methods: 36 patients with proximal femur tumor were treated with extended tumor resection and prosthetic replacement. 14 patients received prosthetic replacements with the embracing fixators fixing between the junction of the prosthesis stem and the femur temporarily, while the other 22 patients received the same replacements but without the fixators. Following aspects were compared: occurrence of complications, limb function and active hip ROM.Results: There are fewer cases of hip dislocation in the group received prosthetic replacements with the use of embracing fixators. Occurrence of deep infection presented no difference between the two groups. Better limb function and higher active range of motion (ROM) on abduction or flexion were also found in the group using embracing fixators. Conclusion: Ni-Ti shape memory alloy embracing fixator plays a key part in assisting the accurate implantation angle of the prosthesis stem in the prosthetic replacement. The prosthesis stem can be adjusted to the optimal angle with the help of the embracing fixator. Patients have lower chance of dislocation, better limb function, and higher active hip ROM. Trial registration: retrospectively registered.

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Viscoelastic behavior of epoxy resin reinforced with shape-memory-alloy wires

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x20975492 ◽

2020 ◽

pp. 1045389X2097549

Author(s):

Niloufar Bagheri ◽

Mahmood M Shokrieh ◽

Ali Saeedi

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Epoxy Resin ◽

Volume Fraction ◽

Niti Alloy ◽

Micromechanical Model ◽

Viscoelastic Behavior ◽

Mechanical Analysis ◽

Reinforced Polymer ◽

Small Volume Fraction

The effect of NiTi alloy long wires on the viscoelastic behavior of epoxy resin was investigated by utilizing the dynamic mechanical analysis (DMA) and a novel micromechanical model. The present model is capable of predicting the viscoelastic properties of the shape-memory-alloy (SMA) reinforced polymer as a function of the SMA volume fraction, initial martensite volume fraction, pre-strain level in wires, and the temperature variations. The model was verified by conducting experiments. Good agreement between the theoretical and experimental results was achieved. A parametric study was also performed to investigate the effect of SMA parameters. According to the results, by the addition of a small volume fraction of SMA, the storage modulus of the composite increases significantly, especially at higher temperatures. Moreover, applying a 4% pre-strain caused a 10% increase in the maximum value of the loss factor of the SMA reinforced epoxy in comparison with the 0% pre-strained SMA reinforced epoxy.

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Determination of virial stress on atoms using 2nd nearest neighbour embedded atomic model (2NNEAM) for a nitinol shape memory alloy (SMA)

Materials Today Proceedings ◽

10.1016/j.matpr.2019.11.042 ◽

2020 ◽

Vol 26 ◽

pp. 229-234

Author(s):

Dheeraj K. Gara

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Atomic Model ◽

Nearest Neighbour ◽

Virial Stress

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Hysteresis and Anomaly in the Elastic Properties of the Shape Memory Alloy Ni0.507Ti0.493

phys stat sol (a) ◽

10.1002/1521-396x(200205)191:1<42::aid-pssa42>3.0.co;2-j ◽

2002 ◽

Vol 191 (1) ◽

pp. 42-48 ◽

Cited By ~ 2

Author(s):

Jino Bak ◽

Mun Dae Kim ◽

Chul Koo Kim ◽

M. Kaack ◽

J. Pelzl ◽

...

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Elastic Properties

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Determination of microstructure and twinning relationship between martensitic variants in 53 at.%Ni–25 at.%Mn–22 at.%Ga ferromagnetic shape memory alloy

Journal of Applied Crystallography ◽

10.1107/s0021889806027488 ◽

2006 ◽

Vol 39 (5) ◽

pp. 723-727 ◽

Cited By ~ 41

Author(s):

D. Y. Cong ◽

Y. D. Zhang ◽

Y. D. Wang ◽

C. Esling ◽

X. Zhao ◽

...

Keyword(s):

High Resolution ◽

Shape Memory Alloy ◽

Shape Memory ◽

Electron Backscatter Diffraction ◽

Ferromagnetic Shape Memory Alloy ◽

Resolution Electron ◽

Ferromagnetic Shape Memory ◽

Backscatter Diffraction ◽

Martensitic Variants

A recent study by high-resolution neutron powder diffraction provided accurate crystallographic information for the newly developed ferromagnetic shape memory alloy 53 at.%Ni–25 at.%Mn–22 at.%Ga. This made it possible to study by high-resolution electron backscatter diffraction the local microstructures and the twinning relationships between martensitic variants. The twin interfaces were also investigated and they are found to be coherent on the {112} planes.

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Determination of Preferred Morphology of Self-Accommodating Martensite in Ti-Nb-Al Shape Memory Alloy Using Optical Microscopy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.922.260 ◽

2014 ◽

Vol 922 ◽

pp. 260-263 ◽

Cited By ~ 1

Author(s):

Masatoshi Ii ◽

Masaki Tahara ◽

Hideki Hosoda ◽

Shuichi Miyazaki ◽

Tomonari Inamura

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Optical Microscopy ◽

Early Stage ◽

Type I ◽

Type Ii ◽

Different Types ◽

Forward Transformation

The preferred morphology of self-accommodation (SA) microstructure in a Ti-Nb-Al shape memory alloy was investigated by the evaluation of the frequency distribution of the habit plane variant (HPV) clusters using in-situ optical microscopy. The observed HPV clusters were classified into two different types; one is the cluster connected by the {111}o type I twin (Type I) and the other is connected by the <211>o type II twin (Type II). The total fractions of the Type I and Type II clusters were 52% and 48%, respectively. The incompatibility at junction planes (JPs) of the two clusters was almost the same among these clusters. However, most of the larger martensite plates (> 50μm) formed Type I cluster at the later stage of the reverse martensitic transformation, i.e., at the early stage of the forward transformation upon cooling. The ratio of the fraction of Type I and II is almost 2:1 at the early stage of the forward transformation.

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