Constitutive Model of Shape Memory Alloys: One-Dimensional Phase Transformation Model

2008 ◽  
pp. 84-91
Author(s):  
Tadashige Ikeda
Keyword(s):  
Phase Transformation ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Transformation Model ◽  
One Dimensional

Constitutive Model of Shape Memory Alloys: One-Dimensional Phase Transformation Model

2008 ◽  
Vol 56 ◽  
pp. 84-91
Author(s):  
Tadashige Ikeda
Keyword(s):  
Phase Transformation ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Strain Rate ◽  
Shape Memory ◽  
Strain Rate Effect ◽  
Rate Effect ◽  
Reverse Transformation ◽  
Stress Strain ◽  
One Dimensional

A simple yet accurate macroscopic constitutive model of shape memory alloys has been developed. The features of this model are (1) energy-based phase transformation criterion, (2) one-dimensional phase transformation rule based on a micromechanical viewpoint, (3) dissipated energy with a form of a sum of two exponential functions, (4) duplication of the strain rate effect, and (5) adaptability to multi-phase transformation. This model is further improved to be able to express stress-strain relationships such that the reverse transformation starts at a higher stress than the martensitic transformation starts. Here, the ideal reversible transformation temperature is empirically described by a function of the martensite volume fraction. In this paper, an outline of our model is given, where the improvement is introduced. Then, it is shown that the model can quantitatively duplicate the major and minor hysteresis loops, strain rate effect, and asymmetry in tension and compression on the stress-strain relationship. And that it can also duplicate the stress-strain relationships having the reverse transformation start stress higher than the forward one.

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.

scholarly journals An analytical model for crack monitoring of the shape memory alloy intelligent concrete

2019 ◽  
Vol 31 (1) ◽  
pp. 100-116 ◽  
Author(s):  
Bingfei Liu ◽  
Qingfei Wang ◽  
Kai Yin ◽  
Liwen Wang
Keyword(s):  
Shape Memory Alloy ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Monitoring Model ◽  
Crack Monitoring ◽  
The One

A theoretical model for the crack monitoring of the shape memory alloy intelligent concrete is presented in this work. The mechanical properties of shape memory alloy materials are first given by the experimental test. The one-dimensional constitutive model of the shape memory alloys is reviewed by degenerating from a three-dimensional model, and the behaviors of the shape memory alloys under different working conditions are then discussed. By combining the electrical resistivity model and the one-dimensional shape memory alloy constitutive model, the crack monitoring model of the shape memory alloy intelligent concrete is given, and the relationships between the crack width of the concrete and the electrical resistance variation of the shape memory alloy materials for different crack monitoring processes of shape memory alloy intelligent concrete are finally presented. The numerical results of the present model are compared with the published experimental data to verify the correctness of the model.

OS1001 A Constitutive Model for Stress and Temperature Induced Phase Transformation of Shape Memory Alloys under Multi-axial Stress

2008 ◽  
Vol 2008 (0) ◽  
pp. _OS1001-1_-_OS1001-2_ ◽  
Author(s):  
Akihiko Suzuki ◽  
Wakako Araki ◽  
Hideo Shibutani ◽  
Takaei Yamamoto ◽  
Toshio Sakuma
Keyword(s):  
Phase Transformation ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Axial Stress

Constitutive model for the numerical analysis of phase transformation in polycrystalline shape memory alloys

2012 ◽  
Vol 32-33 ◽  
pp. 155-183 ◽  
Author(s):  
Dimitris Lagoudas ◽  
Darren Hartl ◽  
Yves Chemisky ◽  
Luciano Machado ◽  
Peter Popov
Keyword(s):  
Phase Transformation ◽  
Numerical Analysis ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory
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