scholarly journals Role of Glass Composition on Mechanical Properties of Shape Memory Alloy-Metallic Glass Composites

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Supat Chupradit ◽  
Indah Raya ◽  
Dinh Tran Ngoc Huy ◽  
Dmitry Bokov ◽  
Pham Van Tuan ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Md Simulation ◽  
Shear Bands ◽  
Laminated Composite ◽  
Softening Effect ◽  
Glass Composites ◽  
Wide Range ◽  
Tension Loading

In this work, the molecular dynamics (MD) simulation was applied to design a laminated composite structure comprised of the shape memory alloy (SMA) and Cu-Zr metallic glasses (MGs). A wide range of MG compositions was considered to tune the mechanical features and improve the homogenous plastic deformation during the tension loading. The results indicated that the martensitic transformation in the SMA inhibited the sudden shear band propagation in the composite for all the samples. Moreover, it was revealed that the mechanism of plasticity was significantly affected by the change of MG composition. In the Cu-rich MGs, the formation and propagation of thick shear bands occurred at the end of the tension loading; however, the increase in Zr content induced the interaction of multiple shear bands with finer configurations in the system. Nevertheless, the excessive Zr addition in the MG composition facilitated the aggregation of nanopores at the interface of SMA and MGs, which may be due to the softening effect in the Zr-rich MGs. Finally, it is concluded that an optimized MG composition is required for the trade-off between the plasticity and the strength in the SMA-MG composites.

scholarly journals The Role of Nickel-titanium Shape Memory Alloy Embracing Fixator in Determination of the Implantation Angle of Hip Tumor Prosthesis Stem Following Tumor Resection and the Analysis of Its Efficacy: a Retrospective Study

2021 ◽  
Author(s):  
Yang Wang ◽  
Panyu Zhou ◽  
Demeng Xia ◽  
Yunyun Wang ◽  
Sheng Wang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Tumor Resection ◽  
Hip Dislocation ◽  
Nickel Titanium ◽  
Prosthetic Replacement ◽  
Limb Function ◽  
Tumor Prosthesis

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.

A simplified analytical model to simulate martensite reorientation and plasticity in shape memory alloy ring couplers

2021 ◽  
pp. 1045389X2110572
Author(s):  
Fabrizio Niccoli ◽  
Valentina Giovinco ◽  
Cedric Garion ◽  
Carmine Maletta ◽  
Paolo Chiggiato
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
High Vacuum ◽  
Ring Expansion ◽  
Particle Accelerators ◽  
European Organization ◽  
Elastic Plastic ◽  
Wide Range ◽  
Martensite Reorientation

Recent studies on Shape Memory Alloy rings have been undertaken at the European Organization for Nuclear Research (CERN) to develop smart and leak-tight couplers for Ultra High Vacuum systems of particle accelerators. A special thermo-mechanical process (training) is needed to provide SMA rings with proper functional properties, that is to allow thermal mounting, dismounting, and leak tight coupling within a given service temperature window. Low temperature ring expansion is a crucial part of the training process as it gives suitable size, shape recovery properties, and thermal stability range to the SMA element. An analytical model, based on simplified elastic-plastic axisymmetric concepts, has been developed and implemented in a commercial software to simulate isothermal SMA rings expansions. It is particularly useful to predict the final size of a martensitic SMA coupler as a function of the initial dimensions and of the pre-deformation parameters. The effectiveness of the model has been demonstrated by analyzing the stress/deformation field occurring in a wide range of ring geometries for different load cases including martensite reorientation and plasticity. The predictions of the analytical model have been systematically compared with those obtained by axisymmetric finite element (FE) analyses based on elastic-plastic constitutive models and experimental measurements.

Role of Shape Memory Alloy Wires as a SENSAPTIC HMI Device

2020 ◽  
Vol 20 (12) ◽  
pp. 6422-6431
Author(s):  
D. Josephine Selvarani Ruth ◽  
K. Dhanalakshmi
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory

scholarly journals Modeling the behavior of bilayer shape memory alloy/functionally graded material beams considering asymmetric shape memory alloy response

2019 ◽  
Vol 31 (1) ◽  
pp. 84-99 ◽  
Author(s):  
Nguyen Van Viet ◽  
Wael Zaki ◽  
Rehan Umer ◽  
Quan Wang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Functionally Graded Material ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Alloy Layer ◽  
Functionally Graded ◽  
Tension And Compression ◽  
Graded Material ◽  
Asymmetric Shape

A new model is proposed to describe the response of laminated composite beams consisting of one shape memory alloy layer and one functionally graded material layer. The model accounts for asymmetry in tension and compression of the shape memory alloy behavior and successfully describes the dependence of the position of the neutral surface on phase transformation within the shape memory alloy and on the load direction. Moreover, the model is capable of describing the response of the composite beam to both loading and unloading cases. In particular, the derivation of the equations governing the behavior of the beam during unloading is presented for the first time. The effect of the functionally graded material gradient index and of temperature on the neutral axis deviation and on the overall behavior of the beam is also discussed. The results obtained using the model are shown to fit three-dimensional finite element simulations of the same beam.

scholarly journals Vibrational Analysis of Composite Beam Embedded with Nitinol Shape Memory Alloy Wires

2018 ◽  
Vol 7 (3.4) ◽  
pp. 143
Author(s):  
Omer Muwafaq Mohmmed Ali ◽  
Rawaa Hamid Mohammed Al-Kalali ◽  
Ethar Mohamed Mahdi Mubarak
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Frequency Response ◽  
Response Curve ◽  
Natural Frequencies ◽  
Damping Ratio ◽  
Vibrational Analysis ◽  
Laminated Composite ◽  
Vibration Modes ◽  
Frequency Response Curve

In this paper, laminated composite materials were hybridized with fibers (E-glass) and shape memory alloy wires which considered a smart material. The effect of changing frequency on the (acceleration- frequency) response curve, the damping ratio of the vibration modes, the natural frequencies of the vibration mode, the effect of shape memory alloy wires number on the damping characteristics were studied. Hand lay-up technique was used to prepare the specimens, epoxy resin type was used as a matrix reinforced by fiber, E-glass. The specimens were manufactured by stacking 2 layers of fibers. Shape memory alloy, type Nitinol (nickel-titanium) having a diameter (1 and 2mm), was used to manufacture the specimens by embedding (1,2 and 3) wires into epoxy. Experimentally, the acceleration- frequency response curve was plotted for the vibration modes, this curve was used to measure the natural frequencies of the vibration modes and calculate the damping ratio of the vibration modes. ANSYS 15- APDL was used to determine the mode shape and find the natural frequencies of the vibration modes then compared with the experimental results. The results illustrated that, for all specimens increasing the natural frequency leads to decreasing the damping ratio. Increasing the number of shape memory alloy wires leads to increase the values of the damping ratio of the vibration modes and the natural frequencies of the vibration modes at room temperature. 

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