Equivalent linear elastic-viscous model of shape memory alloy for isolated structures

2016 ◽  
Vol 99 ◽  
pp. 1-8 ◽  
Author(s):  
Sharad Ghodke ◽  
R.S. Jangid
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Linear Elastic ◽  
Equivalent Linear ◽  
Isolated Structures

Study on Shape Memory Alloy Plate with Circular Hole under Biaxial Uneven Tension

2012 ◽  
Vol 457-458 ◽  
pp. 994-997
Author(s):  
Bo Zhou ◽  
Xu Kun Li ◽  
Gang Ling Hou
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Circular Hole ◽  
Complex Stress ◽  
Complex Stress State ◽  
Transformation Model ◽  
Alloy Plate ◽  
Linear Elastic ◽  
The One

This paper focuses on the thermo-mechanical behaviors of a shape memory alloy (SMA) plate with a circular hole under biaxial uneven tension. The phase transformation behaviors of SMA under complex stress state are formulated based on the one-dimensional phase transformation model developed by Zhou and Yoon. The stress field equation of the SMA plate with a circular hole is derived according to linear elastic mechanics. The phase transformation behaviors near the region around the circular hole are numerically simulated under different conditions of applied stress.

Development of a shape memory alloy multiple-point injector for chemotherapy

2005 ◽  
Vol 219 (3) ◽  
pp. 213-217 ◽  
Author(s):  
W Xu ◽  
T G Frank ◽  
A Cuschieri
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Direct Injection ◽  
Element Model ◽  
Multiple Point ◽  
Linear Elastic ◽  
Outer Needle ◽  
Non Linear ◽  
Deformation Force ◽  
Medical Needle

A medical needle is described that allows injection to take place at multiple sites through a single stab wound. This is achieved by extruding multiple, thin, and curved internal needles from a larger, straight, outer needle. The development and finite element modelling of the shape memory alloy (SMA) inner needles is presented in this paper. A non-linear elastic element model was used in this process to allow for the non-linear properties of the alloy and the large deformations that occur. The model provided maximum strain values and penetration forces for the inner needles. The deformation force on the tip of the needle was measured against displacement to confirm the predicted penetration force. Applications for the device include the treatment of liver cancer by direct injection of alcohol into the tumours.

On the Path-Dependency of the J-Integral in a Pseudoelastic Shape Memory Alloy

2011 ◽  
Author(s):  
Theocharis Baxevanis ◽  
Yves Chemisky ◽  
Dimitris Lagoudas
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Path Dependence ◽  
Crack Tip ◽  
Transformation Strain ◽  
Small Scale ◽  
J Integral ◽  
Transformation Zone ◽  
Linear Elastic ◽  
Path Dependent

Detailed finite-element calculations are carried out to examine the path-dependence of the J-integral in a pseudoelastic Shape Memory Alloy (SMA) for mode I loading under the approximation of linear kinematics. The evolution equation for the transformation strain is consistent with the classical rate-independent J2 flow theory. The small-scale nonlinearity assumption is employed using a boundary layer approach, wherein the actual boundary conditions have been replaced by the requirement of an asymptotic approach to the linear elastic inverse-square-root stress/strain distribution at large distances from the crack tip. The J-integral is found to be path-dependent inside the transformation zone, close to the crack tip.

Shape-memory coaxial bimorphs

2009 ◽  
Vol 223 (11) ◽  
pp. 2713-2716 ◽  
Author(s):  
R Jähne ◽  
L F Campanile
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Shape Recovery ◽  
Design Method ◽  
Smart Structures ◽  
Finite Element Simulations ◽  
Alloy Component ◽  
Linear Elastic

The thermal shape recovery shown by shape memory alloys is a property that makes these materials very attractive for applications in the field of smart structures, e.g. bending actuators. This article shows a design method for coaxial bimorphs that are composed of a linear-elastic and shape memory alloy component, properly coupled. A simple and effective method is proposed to solve for the component designs in order to achieve given bimorph configurations. Analytical examples and finite-element simulations are shown for the case of assigned bimorph's warm shape.

Study on Crack Tip Field of Mode I of Shape Memory Alloy in Plane Strain State

2012 ◽  
Vol 457-458 ◽  
pp. 744-747
Author(s):  
Bo Zhou ◽  
Yan Yan Hou ◽  
Jun Lv
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Crack Tip ◽  
Complex Stress ◽  
Complex Stress State ◽  
Mode I ◽  
Crack Tip Field ◽  
Linear Elastic ◽  
Elastic Mechanics

This paper focuses on the thermo-mechanical behaviors of a shape memory alloy (SMA) plate with a crack of mode I. A phase transformation equation is supposed to express the phase transformation behaviors of SMA under complex stress state. The stress field near the crack tip is described based on linear elastic mechanics. The martensitic phase transformation zones near the crack tip at various temperatures are numerically determined.

Variational Estimates for the Effective Response of Shape Memory Alloy Actuated Fiber Composites

2002 ◽  
Vol 69 (4) ◽  
pp. 470-480 ◽  
Author(s):  
J. P. Briggs ◽  
P. Ponte Castaneda
Keyword(s):  
Composite Materials ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermal Activation ◽  
Fiber Composites ◽  
Homogenization Procedure ◽  
Effective Response ◽  
Linear Elastic ◽  
The Matrix ◽  
Active Composite

The homogenization procedure of Ponte Castan˜eda is used to estimate the effective behavior of active composite materials consisting of aligned shape memory alloy (SMA) fibers embedded in a linear elastic matrix. Results are presented for thermal activation of the SMA with various applied tractions on the composite. While increasing stiffness of the matrix phase inhibits the contraction of the SMA, the simulations indicate that the use of a prestress in the manufacturing of the composite may provide an increase in the response time of the system without reducing performance.

Non-linear elastic behavior of Ni-Fe-Ga(Co) shape memory alloy and Landau-energy landscape reconstruction

2021 ◽  
pp. 117530
Author(s):  
Kristýna Zoubková ◽  
Hanuš Seiner ◽  
Petr Sedlák ◽  
Elena Villa ◽  
Masaki Tahara ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Energy Landscape ◽  
Elastic Behavior ◽  
Linear Elastic ◽  
Landscape Reconstruction ◽  
Non Linear

Study on Elliptical Cross-Section Rod of Shape Memory Alloy Subjected to Torsion Deformation

2012 ◽  
Vol 457-458 ◽  
pp. 511-514
Author(s):  
Bo Zhou ◽  
Xu Kun Li ◽  
Bin Hu
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Cross Section ◽  
Elliptical Cross Section ◽  
Transformation Model ◽  
Elliptical Cross ◽  
Linear Elastic ◽  
Elastic Mechanics ◽  
Torsion Deformation

This paper focuses on the thermo-mechanical behaviors of shape memory alloy (SMA) elliptical cross-section rod subjected to torsion deformation. The stress solution in the elliptical cross-section is derived according to linear elastic mechanics. The phase transformation behaviors of the elliptical cross-section rod are described based on the phase transformation model developed by Zhou and Yoon. The phase transformation zone in the elliptical cross-section is numerically determined and discussed.

Study on Crack Tip Field of Shape Memory Alloy Board under Bending Load

2012 ◽  
Vol 457-458 ◽  
pp. 409-412
Author(s):  
Bo Zhou ◽  
Tai Yue Yin ◽  
Xu Kun Li
Keyword(s):  
Phase Transformation ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Crack Tip ◽  
Transformation Model ◽  
Crack Tip Field ◽  
Transformation Zone ◽  
Linear Elastic ◽  
Bending Load ◽  
Elastic Mechanics

This paper focuses on the thermo-mechanical behaviors of shape memory alloy (SMA) board with a crack subjected to bending load. The stress field near the crack tip of SMA board is described according to the solution of linear elastic mechanics. The phase transformation behaviors of SMA board are formulated based on Zhou’s one-dimensional phase transformation model. The phase transformation zone equation is derived to describe the phase transformation zone near the crack tip.

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