A hybrid elements model of stress-strain hysteresis in shape memory alloys

2009 ◽  
Author(s):  
Yongzhong Huo
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Stress Strain

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.

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.

THE USE OF SHAPE-MEMORY ALLOYS FOR MECHANICAL REFRIGERATION

2009 ◽  
Vol 02 (02) ◽  
pp. 73-78 ◽  
Author(s):  
LLUÍS MAÑOSA ◽  
ANTONI PLANES ◽  
EDUARD VIVES ◽  
ERELL BONNOT ◽  
RICARDO ROMERO
Keyword(s):  
Shape Memory Alloys ◽  
Single Crystal ◽  
Shape Memory ◽  
Large Temperature ◽  
Martensitic Transition ◽  
Stress Strain ◽  
Temperature Changes ◽  
Entropy Changes ◽  
Elastocaloric Effect ◽  
Different Temperatures

This letter reports on stress–strain experiments on a Cu – Zn – Al single crystal performed using a purpose-built tensile device which enables the load applied to the specimen to be controlled while elongation is continuously monitored. From the measured isothermal tensile curves, the stress-induced entropy changes are obtained at different temperatures. These data quantify the elastocaloric effect associated with the martensitic transition in shape-memory alloys. The large temperature changes estimated for this effect, suggest the possibility of using shape-memory alloys as mechanical refrigerators.

Thermomechanical Treatments and Their Influence on the Microstructure and Stress/Strain Diagrams of NiTi Shape Memory Alloys

2004 ◽  
Vol 43 (1) ◽  
pp. 95-108 ◽  
Author(s):  
S.D. Prokoshkin ◽  
I.Yu. Khmelevskaya ◽  
V. Brailovski ◽  
F. Trochu ◽  
S. Turenne ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Stress Strain ◽  
Niti Shape Memory Alloys

Shear Stress–Strain Behavior of Ni-rich and Ti-rich Shape Memory Alloys at High Strain Rates

2014 ◽  
Vol 6 (9) ◽  
pp. 2024-2026 ◽  
Author(s):  
Sung Young ◽  
Jeoung-Han Kim ◽  
Yeon-Wook Kim ◽  
Dong-Teak Chung ◽  
Tae-Hyun Nam
Keyword(s):  
Shear Stress ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Stress Strain ◽  
Strain Behavior

Some stress- strain- temperature relationships for shape memory alloys

1988 ◽  
Vol 19 (10) ◽  
pp. 2407-2413 ◽  
Author(s):  
E. N. Bondaryev ◽  
C. M. Wayman
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Stress Strain
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