Effect of structural transformation and deformation nonlinearity on the stability of a shape memory alloy rod

2010 ◽  
Vol 45 (6) ◽  
pp. 876-884 ◽  
Author(s):  
A. A. Movchan ◽  
I. A. Movchan ◽  
L. G. Sil’chenko
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Structural Transformation ◽  
The Stability

Effect of deformation on the stability of stress-induced martensite in nanocrystalline NiTi shape memory alloy

2014 ◽  
Vol 131 ◽  
pp. 233-235 ◽  
Author(s):  
Xiaobin Shi ◽  
Mengying Yu ◽  
Fangmin Guo ◽  
Zhenyang Liu ◽  
Daqiang Jiang ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Niti Shape Memory Alloy ◽  
The Stability

Theoretical analysis on the adaptive vibration attenuation of a fixed-fixed beam realized by a piezo-shape memory alloy ferrule

2019 ◽  
Vol 30 (14) ◽  
pp. 2079-2090 ◽  
Author(s):  
Longfei Wang ◽  
Ying Wu ◽  
Zishun Liu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Self Regulation ◽  
Nonlinear Dynamic Response ◽  
Adaptive Property ◽  
Proposed Model ◽  
Vibration Attenuation ◽  
The Stability ◽  
System Characteristics ◽  
Fixed Beam

In this article, the vibration attenuation of a fixed-fixed beam with a piezo-shape memory alloy ferrule is theoretically investigated. First, a dynamic model of the beam with a piezo-shape memory alloy ferrule is established, and the nonlinear dynamic response of the model is numerically analysed. The results show that the stability of the beam structure can be improved adaptively through self-regulation of the stiffness of the piezo-shape memory alloy ferrule undergoing external excitations. The effects of some internal system characteristics, such as the ferrule dimensions as well as the initial ferrule temperatures and boundary conditions, on the vibration attenuation of the beam are discussed. The stability of the proposed model under different external factors, including damping and external excitations, is also investigated. Compared with an aluminium ferrule, the present ferrule is better at the suppressing vibrations of the beam, and its adaptive property avoids the structural resonances for bigger ferrule sizes, making it more intelligent, efficient and convenient.

scholarly journals Operational Space Control of a Lightweight Robotic Arm Actuated by Shape Memory Alloy (SMA) Wires

2016 ◽  
Author(s):  
Serket Quintanar-Guzmán ◽  
Somasundar Kannan ◽  
Miguel A. Olivares-Mendez ◽  
Holger Voos
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Closed Loop ◽  
Loop System ◽  
Robotic Arm ◽  
Control Law ◽  
Closed Loop System ◽  
End Effector ◽  
Position Regulation ◽  
The Stability

This paper presents the design and control of a two link lightweight robotic arm using a couple of antagonistic Shape Memory Alloy (SMA) wires as actuators. A nonlinear robust control law for accurate positioning of the end effector of the two-link SMA based robotic arm is developed to handle the hysteresis behavior present in the system. The model presented consists of two subsystems: firstly the SMA wires model and secondly the dynamics of the robotic arm itself. The control objective is to position the robotic arm’s end effector in a given operational plane position. For this regulation problem a sliding mode control law is applied to the hysteretic system. Finally a Lyapunov analysis is applied to the closed-loop system demonstrating the stability of the system under given conditions. The simulation results demonstrate the accurate and fast response of the control law for position regulation. In addition, the stability of the closed-loop system can be corroborated.

Stochastic recruitment control of shape memory alloy cellular actuators based on multi-state Markov chain model

2021 ◽  
pp. 1045389X2110026
Author(s):  
Chen Zhang ◽  
Jianjiang Cui
Keyword(s):  
Markov Chain ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Markov Chain Model ◽  
Open Loop ◽  
Chain Model ◽  
Control Laws ◽  
Loop Control ◽  
Stochastic Recruitment ◽  
The Stability

A new broadcast stochastic recruitment approach to the control of shape memory alloy (SMA) cellular actuators is proposed. The control design is based on a Markov chain model of multi-state cells, which is able to better characterize the inherent hysteresis of SMA in phase transition. The closed-loop and open-loop control laws are derived from random Lyapunov stability analysis and the stability conditions are analyzed. Simulation experiments demonstrate the effectiveness of the proposed method.

Research on stability and nonlinear vibration of shape memory alloy hybrid laminated composite panel under aerodynamic and thermal loads

2016 ◽  
Vol 27 (20) ◽  
pp. 2851-2861 ◽  
Author(s):  
Zhenhua Zhang ◽  
Piao Sheng
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Nonlinear Vibration ◽  
Laminated Composite ◽  
Composite Panel ◽  
Dynamic Equations ◽  
Stable Region ◽  
Thermal Loads ◽  
Aerodynamic Pressure ◽  
The Stability

The stability and nonlinear vibration of a NiTi shape memory alloy hybrid laminated composite panel under aerodynamic and thermal loads are investigated. The partial differential dynamic equations of the shape memory alloy hybrid laminated composite panel are derived based on the large deformation theory, the first-order piston theory of aerodynamic pressure and a simple constitutive model of shape memory alloy. Then, the general expressions of multimode discrete equations of the shape memory alloy hybrid laminated composite panel are obtained for the first time using Galerkin method. The stability of the shape memory alloy hybrid laminated composite panel is analyzed first based on the Routh–Hurwitz criteria, and the results show that the temperature and aerodynamic pressure parameter plane can be divided into a flat and stable region, a flutter region, and a buckling region, and the flat and stable region can be greatly enlarged as the shape memory alloy volume fraction increases. Meanwhile, numerical results of the dynamic equations show that the shape memory alloy hybrid laminated composite panel can produce various dynamic motions, and the bifurcation characteristics of the responses with temperature obtained by numerical method coincide well with the stability boundaries determined by analytical method.

scholarly journals A Biomechanical Research of Growth Control of Spine by Shape Memory Alloy Staples

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Wei Zhang ◽  
Yonggang Zhang ◽  
Guoquan Zheng ◽  
Ruyi Zhang ◽  
Yan Wang
Keyword(s):  
Stainless Steel ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Growth Control ◽  
Biomechanical Properties ◽  
Thoracic Vertebrae ◽  
Recovery Stress ◽  
Pullout Strength ◽  
Functional Spinal Unit ◽  
The Stability

Shape memory alloy (SMA) staples in nickel titanium with shape memory effect are effective for spinal growth control. This study was designed to evaluate the biomechanical properties of the staples and observe the stability of the fixed segments spine after the staples were implanted. According to the vertical distance of the vertebrae, SMA staples of 5, 6.5, and 8 mm were designed. The recovery stress of 24 SMA staples in three groups was measured. The pullout strength of SMA staples and stainless steel staples in each functional spinal unit was measured. Each of the six fresh specimens was divided into three conditions: normal, single staple, and double staples. Under each condition, the angle and torque of spinal movements in six directions were tested. Results show that the differences in recovery stress and maximum pullout strength between groups were statistically significant. In left and right bending, flextion, and extention, the stability of spine was decreased in conditions of single staple and double staples. Biomechanical function of SMA staples was superior to stainless steel staple. SMA staples have the function of hemiepiphyseal compression and kyphosis and scoliosis model of thoracic vertebrae in goat could be successfully created by the fusionless technique.

Unbuckling of superelastic shape memory alloy columns

2018 ◽  
Vol 29 (7) ◽  
pp. 1360-1378 ◽  
Author(s):  
Ryan T Watkins ◽  
John A Shaw
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Compressive Load ◽  
Bending Moment ◽  
Load Level ◽  
Stiff Material ◽  
The Stability ◽  
The Right ◽  
Novel Applications ◽  
Feasible Space

Our recent buckling experiments on superelastic shape memory alloy columns (initially straight rods and tubes) discovered that during axial shortening, certain specimens bent (buckled) at a critical compressive load and then, surprisingly, straightened (unbuckled) at a larger compressive load. This “buckling–unbuckling” phenomenon, defined here as the deviation from and then return to a straight configuration during monotonic loading, is not only an intriguing phenomenon (contrary to the post-buckling behavior of conventional materials) but also presents the possibility for novel applications. This work aims to provide a clearer understanding of when and why unbuckling occurs, presenting the experimental observations of this phenomenon and the stability analysis of a modified Shanley column model that captures the unbuckling behavior. Unbuckling behavior is shown to be a consequence of a secondary branch that deviates from the principal path at a low-load level (critical buckling load), but reattaches to the principal path at a higher load level (unbuckling load). The analysis shows that unbuckling behavior can only occur for certain combinations of column geometries and nonlinear (stiff–soft–stiff) material laws, that is, relatively stout columns with the right sequence of softening/stiffening to create the necessary restorative bending moment to reset the column to a straight configuration. The feasible space is defined by closed-form bounds on geometric and material parameters, along with a sensitivity analysis of these parameters on the amplitude of unbuckling.

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