Design of a Flexible Bending Biomimetic Octopus Arm Unit with Embedded SMA Wires

2010 ◽  
Vol 44-47 ◽  
pp. 2543-2547
Author(s):  
Yu Kui Wang ◽  
Cheng Guo ◽  
Jian Li ◽  
Zhen Long Wang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model

This paper discusses a design of a flexible bending biomimetic octopus arm unit. Firstly, bending function of the octopus arm is analyzed. Secondly, the structure of the arm unit driven by shape memory alloy (SMA) is presented which can realize flexible bending. Meanwhile, mechanical model of the arm unit is established to find the proper parameters of the arm unit. Finally, experiments are carried out to demonstrate the feasibility of the structure.

A thermo-mechanical model for shape memory alloy–based crank heat engines

2014 ◽  
Vol 26 (6) ◽  
pp. 652-662
Author(s):  
Fabrizio Niccoli ◽  
Carmine Maletta ◽  
Emanuele Sgambitterra ◽  
Franco Furgiuele
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Heat Engines

scholarly journals A Tetra-State Hopping Robot Driven by Shape Memory Alloy Spring

2011 ◽  
Vol 2-3 ◽  
pp. 402-407 ◽  
Author(s):  
Tian Qi Liu ◽  
Shu Ping Chen ◽  
Jiang Long Guo ◽  
Zhi Long Dou ◽  
Chun Liu ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Lagrange Method ◽  
Hopping Robot ◽  
Jumping Robot

According to the characteristics of jumping locomotion, a solution of Tetra-state Hopping Robot (for short: THR) actuated by Shape Memory Alloy Spring (for short: SMAS) is presented in this paper. This article establishes a mechanical model of the jumping robot and analyzes the kinematics and the dynamics of the mechanical model. Lagrange method is applied to analyze the dynamics the mechanical model. Meanwhile, a preliminary explanation of the THR flipping phenomenon during the take-off and flight process is conducted from the perspective of momentum moment.

scholarly journals Modeling and Experimental Research of One Kind of New Planar Vortex Actuator Based on Shape Memory Alloy

Actuators ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Xiangsen Kong ◽  
Yilei Gu ◽  
Jiajun Wu ◽  
Yang Yang ◽  
Xing Shen
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Angular Displacement ◽  
Complex Structure ◽  
Maximum Error ◽  
Coefficient Of Determination ◽  
Minimum Error ◽  
Output Torque ◽  
The Relationship

In order to alleviate the problems of complex structure and low reliability of traditional Shape Memory Alloy (SMA) rotary actuator, a planar vortex actuator (PVA) based on SMA material was proposed to directly output torque and angular displacement. Based on the calculation method of PVA and the constitutive model of the phase transition equation of SMA, the mechanical model is established, and the pre-tightening torque, temperature, output torque, and rotation angle are obtained. The relationship expression between the tests has verified the mechanical model. The results show that the relationship between the excitation temperature and the output torque, the coefficient of determination between the calculated value and the tested value, is 0.938, the minimum error is 0.46%, and the maximum error is 49.8%. In the relationship between angular displacement and torque, the coefficient of determination between the calculated value and the test value is 0.939, the maximum error is 58.5%, and the minimum error is 28.0%. The test results show that the calculated values of mechanical model and experimental data have similar representation form.

scholarly journals Induction heating of a shape memory alloy beam

2018 ◽  
Vol 83 (3) ◽  
pp. 30905 ◽  
Author(s):  
S. Dufour ◽  
G. Vinsard
Keyword(s):  
Temperature Field ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Induction Heating ◽  
Mechanical Model ◽  
Eddy Currents ◽  
Shape Change ◽  
Nickel Titanium ◽  
Thin Shells ◽  
Induced Currents

The shape memory alloy heating by eddy currents is a quick solution for the shape change. Then, the analysis of the temperature field as a function of the shape is important to build a mechanical model in large deformation. Even if the temperature can be obtained by experiment, a computational model is useful. The computation of the induced currents in a nickel–titanium shape memory alloy beam is here considered with a T − Ω model adapted to thin shells with the help of a change of coordinates. It allows us to take into account the shape change, without the need of remeshing, as a function of the temperature. Experiments are carried out to validate the model.

Super-Elastic Behavior Analysis of Shape Memory Alloy Vascular Stent

2016 ◽  
Vol 725 ◽  
pp. 405-409 ◽  
Author(s):  
Liang Tao ◽  
Chang Luo ◽  
Wei Xuan Li ◽  
Yao Jiang Zhang
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Elastic Behavior ◽  
Niti Shape Memory Alloy ◽  
Analysis Model ◽  
Vascular Stent ◽  
Free Expansion ◽  
Deformation Equation ◽  
Nonlinear Mechanical

NiTi shape memory alloy (SMA) vascular stent, with good bio-compatibility and super-elastic properties, has become an important medical device in clinical treatment of cardiovascular or cerebrovascular diseases. The free expansion of stent in vessel involves the mechanical behavior of geometric large deformation related to the structure of super-elastic. In this paper, the nonlinear mechanical model for the substructure of NiTi shape memory alloy vascular stent is established, and the displacement deformation equation is derived. The geometric non-linearity of the structure is proved. Furthermore, the geometric nonlinear mechanical model is verified by numerical method. The mechanical analysis model of NiTi shape memory alloy vascular stent is widely used in the field of tracheal stent and so on.

Formulation of a Mechanical Model for Composites With Embedded SMA Actuators

1992 ◽  
Vol 114 (4) ◽  
pp. 670-676 ◽  
Author(s):  
J. Jia ◽  
C. A. Rogers
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Shape Control ◽  
Plate Theory ◽  
Damage Control ◽  
Variable Stiffness ◽  
Dynamic Tuning ◽  
Acoustic Control ◽  
Highly Nonlinear

Shape memory alloy reinforced composites are an extremely versatile class of materials with adaptive characteristics that may be exploited for damage control, active structural acoustic control, dynamic tuning, and shape control. In order to design structures reliably with embedded shape memory alloy actuators, a fundamental mechanical model must be formulated to predict the materials’ variable stiffness, induced moments and loads, and the change of curvature that can result. The mechanical model described in this paper is formulated from the micromechanical behavior of the highly nonlinear shape memory alloy actuators and classical lamination theory. The behavior of typical shape memory alloys will be presented and then used in formulating a one- and two-dimensional model and the results will be applied to plate theory.

scholarly journals Theoretical and Experimental Study of a Thermo-Mechanical Model of a Shape Memory Alloy Actuator Considering Minor Hystereses

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1120
Author(s):  
Rosen Mitrev ◽  
Todor Todorov ◽  
Andrei Fursov ◽  
Borislav Ganev
Keyword(s):  
Mathematical Model ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Mechanical Model ◽  
Pulse Width Modulation ◽  
Classical Model ◽  
Experimental Studies ◽  
Physical Factors ◽  
In Series ◽  
Displacement Force

The paper presents a theoretical and experimental investigation of a thermo-mechanical model of an actuator composed of a shape memory alloy wire arranged in series with a bias spring. The developed mathematical model considers the dynamics of the actuator in the thermal and mechanical domains. The modelling accuracy is increased through the developed algorithm for modelling the minor and sub minor hystereses, thus removing the disadvantages of the classical model. The algorithm improves the accuracy, especially when using pulse-width modulation control, for which minor and sub minor hystereses are likely to occur. Experimental studies show that the system is very sensitive, and there are physical factors whose presence cannot be considered in the mathematical model. The experimental research has shown that setting constant values of the duty cycle is impossible to obtain a stable value of displacement and force. The comparison between the developed mathematical model results and the experimental results shows that the differences are acceptable. The improved modelling serves as a basis for designing such actuators and creating an improved automatic feedback control system to maintain a given displacement (force) or trajectory tracking.

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