2103 Experimental Research on Recovery Stress in TiNi Shape Memory Alloy under Several Loading Conditions

A shape memory alloy (SMA) can remember its original shape and recover from strain due to loading once it is exposed to heat (shape memory effect). SMAs also exhibit elastic response to applied stress above the characteristic temperature at which transformation to austenite is completed (pseudoelasticity or superelasticity). Shape memory effect and pseudoelasticity of SMAs have been addressed by several microscopic thermodynamic and macroscopic phenomenological models using different modeling approaches. The Tanaka and Liang-Rogers models are two of the most widely used macroscopic phenomenological constitutive models for describing SMA behavior. In this paper, we performed sensitivity and uncertainty analysis using Sobol and extended Fourier Amplitude Sensitivity Testing (eFAST) methods for the Tanaka and Liang-Rogers models at different operating temperatures and loading conditions. The stress-dependent and average sensitivity indices have been analyzed and are presented for determining the most influential parameters for these models. The results show that variability is primarily caused by a change in operating temperature and loading conditions. Both models appear to be influenced by the uncertainty in elastic modulus of the material significantly. The analyses presented in this paper aim to provide a better insight for designing applications using SMAs by increasing the understanding of these models’ sensitivity to the input parameters and the cause of output variability due to uncertainty in the same input parameters.

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The Instability Improvement of the Symmetric Angle-Ply and Cross-Ply Composite Plates with Shape Memory Alloy Using Finite Element Method

Advances in Mechanical Engineering ◽

10.1155/2014/632825 ◽

2014 ◽

Vol 6 ◽

pp. 632825 ◽

Cited By ~ 2

Author(s):

Zainudin A. Rasid ◽

Rizal Zahari ◽

Amran Ayob

Keyword(s):

Finite Element ◽

Shape Memory Alloy ◽

Shape Memory ◽

Volume Fraction ◽

Shear Deformation Theory ◽

Composite Plates ◽

Element Formulation ◽

Recovery Stress ◽

Buckling Behavior ◽

Post Buckling

Shape memory alloy (SMA) wires were embedded within laminated composite plates to take advantage of the shape memory effect property of the SMA in improving post-buckling behavior of composite plates. A nonlinear finite element formulation was developed for this study. The plate-bending formulation used in this study was developed based on the first order shear deformation theory, where the von Karman's nonlinear moderate strain terms were added to the strain equations. The effect of the SMA was captured by adding recovery stress term in the constitutive equation of the SMA composite plates. Values of the recovery stress of the SMA were determined using Brinson's model. Using the principle of virtual work and the total Lagrangian approach, the final finite element nonlinear governing equation for the post-buckling of SMA composite plates was derived. Buckling and post-buckling analyses were then conducted on the symmetric angle-ply and cross-ply SMA composite plates. The effect of several parameters such as the activation temperature, volume fraction, and the initial strain of the SMA on the post-buckling behavior of the SMA composite plates were studied. It was found that significant improvements in the post-buckling behavior for composite plates can be attained.

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Middle ear vibrations with SMA prosthesis. Experimental research

MATEC Web of Conferences ◽

10.1051/matecconf/201814812001 ◽

2018 ◽

Vol 148 ◽

pp. 12001

Author(s):

Rafal Rusinek ◽

Marcin Szymanski ◽

Grzegorz Teresinski

Keyword(s):

Transfer Function ◽

Shape Memory Alloy ◽

Shape Memory ◽

Temporal Bone ◽

Experimental Research ◽

Middle Ear ◽

Round Window ◽

Laser Doppler Vibrometer ◽

Laser Doppler ◽

Middle Ear Prosthesis

The paper focuses on experimental research of a middle ear prosthesis made of shape memory alloy. The prosthesis provides better adjustment to individual patient than classical prosthesis. The shape memory prosthesis is implemented to a fresh temporal bone and vibrations of the round window are recorded by means of the Laser Doppler Vibrometer. Finally, the results are presented in the form of transfer function and compared to the intact and damaged middle ear.

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Recovery Stress of TiNi Shape Memory Alloy. 2nd Report. Properties under Constant Maximum Strain.

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A ◽

10.1299/kikaia.60.120 ◽

1994 ◽

Vol 60 (569) ◽

pp. 120-125 ◽

Cited By ~ 2

Author(s):

Ping-Hua Lin ◽

Hisaaki Tobushi ◽

Kimio Kimura ◽

Hiroyuki Iwanaga ◽

Takeharu Hattori

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Maximum Strain ◽

Recovery Stress ◽

Constant Maximum

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Experimental Research on Two-way Shape Memory Effect of TiNi Shape Memory Alloy

The proceedings of the JSME annual meeting ◽

10.1299/jsmemecjo.2004.6.0_279 ◽

2004 ◽

Vol 2004.6 (0) ◽

pp. 279-280

Author(s):

Tomohiro KATOH ◽

Masataka TOKUDA ◽

Tadashi INABA ◽

Masakazu YAMAZAKI ◽

Kazuhiro KITAMURA

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Experimental Research

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Influence of Processing State on Recovery Stress in NiTiNb Shape Memory Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.1525 ◽

2014 ◽

Vol 875-877 ◽

pp. 1525-1528 ◽

Cited By ~ 3

Author(s):

Er Min Wang ◽

Qi Hu Hong ◽

Zhi Ming Ni ◽

Jin Han

Keyword(s):

Shape Memory Alloy ◽

Shape Memory ◽

Stress Level ◽

Microstructure Evolution ◽

Hot Rolling ◽

Cold Drawing ◽

Eutectic Microstructure ◽

Recovery Stress ◽

Tini Phase

Self-made tension machine was used to measure the evolution of recovery stress under different processing state for NiTiNb alloy. Then, SEM was used to investigate the microstructure evolution. The results show that the range of the highest recovery stress for forged NiTiNb alloy is between 210-215MPa. Otherwise, the recovery stress level of the samples enduring cold drawing and hot rolling is basically same, which all belong to the rage of 210-220MPa. After forging, the firstly precipitated TiNi phase particles become fine, only 5-8μm. The Nb tablets in eutectic microstructure, which originally contributed between TiNi phase particles, appear spheroidization.

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