Modified thermomechanical modeling approach for shape memory alloy behavior

2003 ◽  
Author(s):  
G. M. Kamath ◽  
G. N. Dayananda ◽  
R. Senthilpriya
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Modeling Approach ◽  
Thermomechanical Modeling

The Concept of Physical Metric in the Thermomechanical Modeling of Phase Transformations With Emphasis on Shape Memory Alloy Materials

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Vassilis P. Panoskaltsis ◽  
Lazaros C. Polymenakos ◽  
Dimitris Soldatos
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Phase Transformations ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Material Model ◽  
Internal Variable ◽  
Theoretical Interest ◽  
Numerical Examples ◽  
Thermomechanical Modeling

In this work we derive a new version of generalized plasticity, suitable to describe phase transformations. In particular, we present a general multi surface formulation of the theory which is capable of describing the multiple and interacting loading mechanisms, which occur during phase transformations. The formulation relies crucially on the consideration of the intrinsic material (“physical”) metric as a primary internal variable and does not invoke any decomposition of the kinematical quantities into elastic and inelastic (transformation induced) parts. The new theory, besides its theoretical interest, is also important for application purposes such as the description and the prediction of the response of shape memory alloy materials. This is shown in the simplest possible setting by the introduction of a material model. The ability of the model in simulating several patterns of the experimentally observed behavior of these materials such as the pseudoelastic phenomenon and the shape memory effect is assessed by representative numerical examples.

scholarly journals Ni-Mn-Ga single crystal Shape Memory Alloy magneto-thermomechanical modeling

2010 ◽  
Vol 6 ◽  
pp. 29003 ◽  
Author(s):  
J.Y. Gauthier ◽  
C. Lexcellent ◽  
A. Hubert ◽  
J. Abadie ◽  
N. Chaillet
Keyword(s):  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Crystal Shape ◽  
Thermomechanical Modeling

Dynamic Thermomechanical Modeling of a Wet Shape Memory Alloy Actuator

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Joel D. Ertel ◽  
Stephen A. Mascaro
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Temperature Change ◽  
Cold Water ◽  
Thermomechanical Model ◽  
Martensite Fraction ◽  
Mechanical Models ◽  
Strain Martensite ◽  
The Wire ◽  
Thermomechanical Modeling

This paper presents combined thermal and mechanical models of a wet shape memory alloy (SMA) wire actuator. The actuator consists of a SMA wire suspended concentrically in a compliant tube. Actuation occurs as hot and cold water that are alternately pumped through the tube to contract and extend the wire, respectively. The thermomechanical model presented in this paper accounts for the nonuniform temperature change of the SMA wire due to alternating the temperature of the flow along the wire. The thermal portion of the model consists of analysis of the heat transfer between the fluid and the SMA wire. Heat loss to the environment and the temperature change of the fluid through the actuator are taken into account. Based on this analysis, the temperature of the wire at segments along its length can be determined as a function of time. The mechanical portion of the model approximates the strain-martensite fraction and martensite fraction-temperature relationships. By combining the thermal and mechanical models, the displacement of the wire can be determined as a function of time. The combined thermomechanical model will be useful for predicting the performance of wet SMA actuators in a variety of applications.

scholarly journals Thermomechanical Modeling of Shape Memory Alloys with Rate Dependency on the Pseudoelastic Behavior

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jin-Ho Roh
Keyword(s):  
Shape Memory Alloy ◽  
Constitutive Model ◽  
Shape Memory ◽  
Loading Rate ◽  
Strain Rates ◽  
Rate Dependency ◽  
Strain Rate Dependency ◽  
Improved Model ◽  
Thermomechanical Modeling ◽  
Pseudoelastic Behavior

The loading-rate dependency on the pseudoelastic behaviors of shape memory alloy (SMA) wires is experimentally and numerically investigated. The results are analyzed to estimate the parameters for a thermomechanical constitutive model of SMA wire with strain-rate dependency of the hysteresis behavior. An analytical model of SMAs is developed by using nonconstant parameters during various strain rates. Numerical simulations are performed to demonstrate the accuracy of the improved model.

Structure and mobility of martensite variant interfaces in a Cu-Zn-AI shape memory alloy

2003 ◽  
Vol 112 ◽  
pp. 519-522 ◽  
Author(s):  
W. Cai ◽  
J. X. Zhang ◽  
Y. F. Zheng ◽  
L. C. Zhao
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Martensite Variant
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