scholarly journals Recovery Behavior of Fe-Based Shape Memory Alloys under Different Restraints

2020 ◽  
Vol 10 (10) ◽  
pp. 3441 ◽  
Author(s):  
Ki-Nam Hong ◽  
Yeong-Mo Yeon ◽  
Won-Bo Shim ◽  
Do-Hyung Kim
Keyword(s):  
Yield Strength ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Heating Temperature ◽  
Experimental Results ◽  
Recovery Stress ◽  
Confining Stress ◽  
Recovery Behavior ◽  
Direct Tensile ◽  
Direct Tensile Test

This paper presents the experimental results of an evaluation of the recovery behavior of Fe-based shape memory alloys (Fe-SMAs) under different restraints. For the study, three types of Fe-SMA (FSMA-A, FSMA-B, FSMA-C) were produced. As a result of the direct tensile test, the yield strength of the FSMA-A specimen was nearly 34% higher than the strength of FSMA-B and FSMA-C. Under free restraint, the recovery strains are 0.00956, 0.01445, and 0.01977 for FSMA-A, FSMA-B and FSMA-C specimens, respectively, after activation when the pre-strain is 0.04, and the heating temperature 200 °C. Under rigid restraint, the final recovery stresses are 518, 391 and 401 MPa for FSMA-A, FSMA-B, FSMA-C specimens after activation when a pre-strain of 0.04 and heating temperature 200 °C. Additionally, under the rigid restraint, the effect of pre-strain on the final recovery stress was insignificant, whereas the final recovery stress increased as the heating temperature increased. When Fe-SMA was constrained during cooling, the recovery stress is 50% lower than under rigid restraint. Hence, in order to develop a large recovery stress, Fe-SMA must be constrained during heating. In addition, a method for calculating the effective confining stress of the Fe-SMA coupler for pipe joining was proposed based on the experimental results.

Smart polyimide with recovery stress at the level of high temperature shape memory alloys

2021 ◽  
Vol 30 (3) ◽  
pp. 035027
Author(s):  
Deyan Kong ◽  
Jie Li ◽  
Anru Guo ◽  
Jianxin Yu ◽  
Xinli Xiao
Keyword(s):  
High Temperature ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Recovery Stress

Research on PA Heat-Melt Adhesive Being Used as Self-Healing Agent in Cementitious Materials

2011 ◽  
Vol 374-377 ◽  
pp. 1899-1903
Author(s):  
Xiong Zhou Yuan ◽  
Wei Sun ◽  
Xiao Bao Zuo
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Chemical Stability ◽  
Bonding Strength ◽  
Research Team ◽  
Cementitious Materials ◽  
Experimental Results ◽  
Self Healing ◽  
Detailed Consideration ◽  
Healing Agent

Based on detailed consideration of the autonomic healing concept of microencapsulated healing agent, micro- bacteria induced calcite and shape memory alloys, our research team proposed a new self-healing technique coupled with of SMA and heat-melt adhesive. In this article, chemical stability and bonding strength with cementitious materials of PA heat-melt adhesive were tested. Experimental results show that PA heat-melt adhesive may contain the ability being used in self-healing techniques coupled with SMA.

Deployable Process Analysis of Packaged SMP Sandwich Beam

2010 ◽  
Vol 123-125 ◽  
pp. 943-946 ◽  
Author(s):  
Zheng Fa Li ◽  
Zheng Dao Wang
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Sandwich Structure ◽  
Shape Recovery ◽  
Process Analysis ◽  
Sandwich Beam ◽  
Shape Memory Polymers ◽  
Recovery Stress ◽  
Recovery Response

Shape memory polymers own many advantages compared with traditional shape memory alloys or ceramics. In order to improve their shape recovery stress and realize a stable recovery response during the deployable process, the structure of SMP sandwich beam composed of two metallic skin and one SMP core is considered. The recovery behaviors of pure SMP and SMP beams reinforced by one-layer metallic skin are also discussed for comparison. The results confirm that the deployable properties of SMP matrix can be significantly improved by using sandwich structure.

scholarly journals Thermodynamical Modelling of Recovery Stress Associated with R-Phase Transformation in TiNi Shape Memory Alloys

1994 ◽  
Vol 35 (5) ◽  
pp. 325-331 ◽  
Author(s):  
Sylvain Leclercq ◽  
Christian Lexcellent ◽  
Hisaaki Tobushi ◽  
Ping-Hua Lin
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Recovery Stress

A Phenomenological Description on Thermomechanical Behavior of Shape Memory Alloys

1990 ◽  
Vol 112 (2) ◽  
pp. 158-163 ◽  
Author(s):  
K. Tanaka
Keyword(s):  
Constitutive Equation ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Thermomechanical Behavior ◽  
Heating Process ◽  
Recovery Stress ◽  
Transformation Kinetics ◽  
Stress Strain ◽  
Temperature Relation ◽  
Ni Alloy

A constitutive theory, which consists of the constitutive equation and the transformation kinetics, is proposed to describe the thermomechanical behaviors of the shape memory alloys. Simulation in Ti-Ni alloy proves a good applicability of the theory when the overall characteristics of the stress-strain-temperature relation and the recovery stress induced in the heating process are studied in the uniaxial state.

The Recovery Behavior of Quenched-In Vacancies in CuAlBe Shape Memory Alloys

1992 ◽  
Vol 105-110 ◽  
pp. 1317-1320
Author(s):  
Tian Min Wang ◽  
Bao Yi Wang ◽  
S.Y. Wang ◽  
Y.Y. Dong ◽  
Guo Zu Da
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Recovery Behavior

scholarly journals A New Rate-Dependent Constitutive Model of Superelastic Shape Memory Alloys and Its Simple Application in a Special Truss Moment Frame Simulation

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Maria I. Ntina ◽  
Dimitrios S. Sophianopoulos
Keyword(s):  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Experimental Results ◽  
Simple Application ◽  
Moment Frame ◽  
Rate Dependent ◽  
Ongoing Work ◽  
Good Agreement

In this work, a new constitutive model of the behavior of shape-memory alloys is presented, based on earlier models, showing a very good agreement with the existing experimental results. A simple approximate application concerning the use of these alloys modelled as dissipation devices in a special truss-moment frame is demonstrated. The results obtained are considered sufficiently encouraging as a motivation for the ongoing work.

scholarly journals Experimental and Numerical Analysis of Recovery Stress in Ni47Ti44Nb9 Shape Memory Alloys: Application to Tightening

2010 ◽  
Author(s):  
Boris Piotrowski ◽  
Etienne Patoor ◽  
Tarak Ben-Zineb ◽  
Andre Eberhardt
Keyword(s):  
Finite Element ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Experimental Tests ◽  
Constitutive Law ◽  
Recovery Stress ◽  
Test Bed ◽  
Home Test ◽  
Niti Sma ◽  
Transformation Hysteresis

Ni47Ti44Nb9 Shape Memory Alloys (SMAs) are widely considered for tightening applications. The alloy is composed of a NiTi SMA matrix containing niobium precipitates. A specific thermomechanical treatment strongly increases the transformation hysteresis in these alloys, what improves the tightening efficiency. Tightening pressures exhibited by Ni47Ti44Nb9 rings are experimentally investigated. Strain gage measurements allow to monitor the tightening pressure using a home test bed. Evolutions with temperature are recorded. A thermo-mechanical constitutive law, specific for Ni47Ti44Nb9, is proposed. It is based on the Mori-Tanaka scale transition technique by considering the precipitates as elastic-plastic inclusions embedded in the SMA matrix. The resulting effective law is implemented, and validated in ABAQUS via UMAT subroutine. Experimental tests are simulated by Finite Element Modeling, and comparisons are performed.

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