A Three-Phase Constitutive Model for TiNiNb Shape Memory Alloys

2010 ◽  
Vol 97-101 ◽  
pp. 660-666
Author(s):  
Jun Wang ◽  
Zhi Ming Hao ◽  
Ping An Shi ◽  
Shao Rong Yu ◽  
Wei Fen Li
Keyword(s):  
Phase Transition ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Conventional Theory ◽  
Material Parameters ◽  
Three Phase ◽  
The Individual

A three-phase constitutive model for TiNiNb shape memory alloys (SMAs) is proposed based on the fact that TiNiNb SMAs are dynamically composed of austenite, martensite and -Nb phases. In the considered ranges of stress and temperature, the behaviors of austenite, martensite and -Nb phases are assumed to be elastoplastic, and the behavior of an SMA is regarded as the dynamic combination of the individual behavior of each phase. Then a macroscopic constitutive description for TiNiNb SMAs is obtained by the conventional theory of plasticity, the theory of mixture, the theory of inclusion, and the description of phase transition by Tanaka. The method for determination of the material parameters is given. This constitutive model can describe the main characteristics of SMAs, such as ferrcelasticity, pseudoelasticity and shape memory effect.

A Three-Phase Constitutive Model and Experimental Study for TiNiNb Shape Memory Alloys

2010 ◽  
Vol 44-47 ◽  
pp. 2453-2461
Author(s):  
Jun Wang ◽  
Zhi Ming Hao ◽  
Ping An Shi ◽  
Shao Rong Yu ◽  
Wei Fen Li
Keyword(s):  
Phase Transition ◽  
Experimental Study ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Conventional Theory ◽  
Material Parameters ◽  
Three Phase ◽  
The Individual

A three-phase constitutive model for TiNiNb shape memory alloys (SMAs) is proposed based on the fact that TiNiNb SMAs are dynamically composed of austenite, martensite and -Nb phases. In the considered ranges of stress and temperature, the behaviors of austenite, martensite and -Nb phases are assumed to be elastoplastic, and the behavior of an SMA is regarded as the dynamic combination of the individual behavior of each phase. Then a macroscopic constitutive description for TiNiNb SMAs is obtained by the conventional theory of plasticity, the theory of mixture, the theory of inclusion, and the description of phase transition by Tanaka. The method for determination of the material parameters is given. This constitutive model can describe the main characteristics of SMAs, such as ferrcelasticity, pseudoelasticity and shape memory effect.

Conventional Plasticity Constitutive Model for Shape Memory Alloys

2011 ◽  
Vol 216 ◽  
pp. 469-473
Author(s):  
Hai Tao Li ◽  
Xiang He Peng
Keyword(s):  
Shape Memory Alloy ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Numerical Algorithm ◽  
Individual Behavior ◽  
Two Phase ◽  
The Individual

A two-phase constitutive model for shape memory alloys (SMAs) is proposed based on the fact that SMAs is dynamically composed of austenite and martensite. The behavior of SMAs is regarded as the dynamic combination of the individual behavior of each phase. This model can describe the main characteristics of SMAs, such as pseudoelasticity and shape memory effect. The corresponding numerical algorithm was also developed to describe the main features of shape memory alloy Au-47.5at.%Cd.

A Constitutive Model for Shape Memory Alloys Involving Transformation, Reorientation and Plasticity

2013 ◽  
Vol 535-536 ◽  
pp. 105-108
Author(s):  
Xiang He Peng ◽  
Min Mei Chen ◽  
Jun Wang
Keyword(s):  
Plastic Deformation ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Volume Fraction ◽  
Transformation Rule ◽  
Constitutive Behavior ◽  
Plastic Parts

A constitutive model is developed for shape memory alloys (SMAs) based on the concept that an SMA is a mixture composed of austenite and martensite. The deformation of the martensite is separated into elastic, thermal, reorientation and plastic parts, and that of the austenite is separated into elastic, thermal and plastic parts. The volume fraction of each phase is determined with the modified Tanaka’s transformation rule. The typical constitutive behavior of some SMAs, including pseudoelasticity, shape memory effect, plastic deformation as well as its effects, is analyzed.

A Multidimensional Constitutive Model for Shape Memory Alloys

2014 ◽  
Vol 584-586 ◽  
pp. 1141-1144
Author(s):  
Wei Wang ◽  
Ji Yuan Liu
Keyword(s):  
Free Energy ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Dissipation Energy ◽  
Thin Walled

A multidimensional constitutive model for shape memory alloys (SMA) is developed in the paper, which is based on the thermodynamics theories of free energy and dissipation energy. This model can well describe both the shape memory effect (SME) and super elasticity effect (SE) of the thin-walled SMA cylinder under an axial tensional force and torsion.

Modeling of Internal Damage Evolution During Actuation Fatigue in Shape Memory Alloys

2018 ◽  
Author(s):  
Francis R. Phillips ◽  
Daniel Martin ◽  
Dimitris C. Lagoudas ◽  
Robert W. Wheeler
Keyword(s):  
Phase Transformation ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Damage Evolution ◽  
Low Cycle Fatigue ◽  
Cycle Fatigue ◽  
Internal Damage ◽  
Functional Fatigue ◽  
Non Linear

Shape memory alloys (SMAs) are unique materials capable of undergoing a thermo-mechanically induced, reversible, crystallographic phase transformation. As SMAs are utilized across a variety of applications, it is necessary to understand the internal changes that occur throughout the lifetime of SMA components. One of the key limitations to the lifetime of a SMA component is the response of SMAs to fatigue. SMAs are subject to two kinds of fatigue, namely structural fatigue due to cyclic mechanical loading which is similar to high cycle fatigue, and functional fatigue due to cyclic phase transformation which typical is limited to the low cycle fatigue regime. In cases where functional fatigue is due to thermally induced phase transformation in contrast to being mechanically induced, this form of fatigue can be further defined as actuation fatigue. Utilizing X-ray computed microtomography, it is shown that during actuation fatigue, internal damage such as cracks or voids, evolves in a non-linear manner. A function is generated to capture this non-linear internal damage evolution and introduced into a SMA constitutive model. Finally, it is shown how the modified SMA constitutive model responds and the ability of the model to predict actuation fatigue lifetime is demonstrated.

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