Feasibility of Shape Memory Alloy Wire Actuation for an Active Steerable Cannula

2015 ◽  
Vol 9 (2) ◽  
Author(s):  
Bardia Konh ◽  
Naresh V. Datla ◽  
Parsaoran Hutapea
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Breast Biopsy ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Needle Insertion ◽  
Design Parameters ◽  
Fe Model ◽  
In Series ◽  
Steerable Cannula

Needle insertion is used in many diagnostic and therapeutic percutaneous medical procedures such as brachytherapy, thermal ablations, and breast biopsy. Insufficient accuracy using conventional surgical cannulas motivated researchers to provide actuation forces to the cannula's body for compensating the possible errors of surgeons/physicians. In this study, we present the feasibility of using shape memory alloy (SMA) wires as actuators for an active steerable surgical cannula. A three-dimensional (3D) finite element (FE) model of the active steerable cannula was developed to demonstrate the feasibility of using SMA wires as actuators to bend the surgical cannula. The material characteristics of SMAs were simulated by defining multilinear elastic isothermal stress–strain curves that were generated through a matlab code based on the Brinson model. Rigorous experiments with SMA wires were done to determine the material properties as well as to show the capability of the code to predict a stabilized SMA transformation behavior with sufficient accuracy. In the FE simulation, birth and death method was used to achieve the prestrain condition on SMA wire prior to actuation. This numerical simulation was validated with cannula deflection experiments with developed prototypes of the active cannula. Several design parameters affecting the cannula's deflection such as the cannula's Young's modulus, the SMA's prestrain, and its offset from the neutral axis of the cannula were studied using the FE model. Real-time experiments with different prototypes showed that the quickest response and the maximum deflection were achieved by the cannula with two sections of actuation compared to a single section of actuation. The numerical and experimental studies showed that a highly maneuverable active cannulas can be achieved using the actuation of multiple SMA wires in series.

Active tuning and maximization of natural frequency in three-dimensional functionally graded shape memory alloy composite structures using meshless local Petrov–Galerkin method

2019 ◽  
Vol 25 (15) ◽  
pp. 2093-2107 ◽  
Author(s):  
Foad Nazari ◽  
Seyed Mahmoud Hosseini ◽  
Mohammad Hossein Abolbashari
Keyword(s):  
Shape Memory Alloy ◽  
Free Vibration ◽  
Shape Memory ◽  
Natural Frequency ◽  
Composite Structures ◽  
Three Dimensional ◽  
Functionally Graded ◽  
Design Parameters ◽  
3D Analysis ◽  
Fiber Reinforced

A mesh-less method based on the local Petrov–Galerkin approach is developed and numerically implemented for active tuning and three-dimensional (3D) analysis of free vibration response of functionally graded (FG) shape memory alloy (SMA) sandwich composites. The local symmetric weak formulation is derived based on the 3D equilibrium equations of elasticity and the field variables are interpolated using the moving-least squares approach. Two main goals are followed. Firstly, free vibration analysis of a sandwich plate made of a SMA fiber reinforced composite core and two FG face sheets are presented. A parametric study is performed to investigate the influences of design parameters on the fundamental natural frequency (FNF) of composite structure and also maximize that. Secondly, SMA wires are embedded to fiber reinforced (FR) composite structures to enable precisely active control of their dynamic characteristics and change that in a required manner. To increase the controllability level and tune the complex exhibits, functionally graded shape memory alloys are considered which have the advantage of combining the functionalities of the shape memory effect and those of FG structures. This paper uses multi-layer activation patterns and the polynomial graded orientation angle of SMA wire along the structure thickness to furnish the FR composite designer with a powerful free vibration control tool. Finally, two activation techniques of SMA wires, the active property tuning (APT) and the active strain energy tuning (ASET) techniques, are compared. It is concluded from all investigated cases that the obtained FNF of ASET technique is always larger than the APT technique.

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.

Design and Optimization of a Shape Memory Alloy-Based Self-Folding Sheet

2013 ◽  
Vol 135 (11) ◽  
Author(s):  
Edwin Peraza-Hernandez ◽  
Darren Hartl ◽  
Edgar Galvan ◽  
Richard Malak
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Three Dimensional ◽  
Building Blocks ◽  
Passive Layer ◽  
Von Mises Stress ◽  
Maximum Temperature ◽  
Radius Of Curvature ◽  
Folding Angle ◽  
The Impact

Origami engineering—the practice of creating useful three-dimensional structures through folding and fold-like operations on two-dimensional building-blocks—has the potential to impact several areas of design and manufacturing. In this article, we study a new concept for a self-folding system. It consists of an active, self-morphing laminate that includes two meshes of thermally-actuated shape memory alloy (SMA) wire separated by a compliant passive layer. The goal of this article is to analyze the folding behavior and examine key engineering tradeoffs associated with the proposed system. We consider the impact of several design variables including mesh wire thickness, mesh wire spacing, thickness of the insulating elastomer layer, and heating power. Response parameters of interest include effective folding angle, maximum von Mises stress in the SMA, maximum temperature in the SMA, maximum temperature in the elastomer, and radius of curvature at the fold line. We identify an optimized physical realization for maximizing folding capability under mechanical and thermal failure constraints. Furthermore, we conclude that the proposed self-folding system is capable of achieving folds of significant magnitude (as measured by the effective folding angle) as required to create useful 3D structures.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Finite Element Analysis of the Nut-Supports Subassembly Based on ANSYS

2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reference Data ◽  
Three Dimensional ◽  
Design Parameters ◽  
Weak Links ◽  
Fe Model ◽  
Element Analysis ◽  
Design And Optimization ◽  
Wave Maker

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.

Corrugated structures reinforced by shape memory alloy sheets: Analytical modeling and finite element modeling

2018 ◽  
Vol 233 (7) ◽  
pp. 2445-2454 ◽  
Author(s):  
Maryam Koudzari ◽  
Mohammad-Reza Zakerzadeh ◽  
Mostafa Baghani
Keyword(s):  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory Alloys ◽  
Finite Element Modeling ◽  
Shape Memory ◽  
Smart Structure ◽  
Design Parameters ◽  
Asymmetric Mode ◽  
Element Modeling ◽  
Structure Changes

In this study, an analytical solution is presented for a trapezoidal corrugated beam, which is reinforced by shape memory alloy sheets on both sides. Formulas are presented for shape memory alloys in states of compression and tension. According to the modified Brinson model, shape memory alloys have different thermomechanical behavior in compression and tension, and also these alloys would behave differently in different temperatures. The developed formulation is based on Euler–Bernoulli theory. Deflection of the smart structure and the effect of asymmetric response in shape memory alloys are studied. Results found from the semi-analytic modeling are compared to and validated through a finite element modeling, and there is more than [Formula: see text] agreement between two solutions. With regard to the results, the neutral axis of the smart structure changes in each section. The maximum deflection ratio of asymmetric mode to symmetric one mode is 1.7. Additionally, the effect of design parameters on deflection is studied in detail.

Design Framework for Multi-Section Shape Memory Alloy Axial Actuators Considering Material and Geometric Uncertainties

2020 ◽  
Author(s):  
Weilin Guan ◽  
Edwin A. Peraza Hernandez
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
High Energy ◽  
High Energy Density ◽  
Design Framework ◽  
Efficient Design ◽  
Cross Sectional ◽  
Geometric Uncertainties ◽  
In Series ◽  
The Wire

Abstract Shape memory alloys are metallic materials with the capability of performing as high energy density actuators driven by temperature control. This paper presents a design framework for shape memory alloy (SMA) axial actuators composed of multiple wire sections connected in series. The various wire sections forming the actuators can have distinct cross-sectional areas and lengths, which can be modulated to adjust the overall thermomechanical response of the actuator. The design framework aims to find the optimal cross-sectional areas and lengths of the wire sections forming the axial actuator such that its displacement vs. temperature actuation path approximates a target path. Constraints on the length-to-diameter aspect ratio and stress of the wire sections are incorporated. A reduced-order numerical model for the multi-section SMA actuators that allows for efficient design evaluations is derived and implemented. An approach to incorporate uncertainty in the geometry and material parameters of the actuators within the design framework is implemented to allow for the determination of robust actuator designs. A representative application example of the design framework is provided illustrating the benefits of using multiple wire sections in axial actuators to modulate their overall response and approximate a target displacement vs. temperature actuation path.

Wet Shape Memory Alloy Actuated Robotic Heart

2009 ◽  
Author(s):  
Joel Ertel ◽  
Stephen Mascaro
Keyword(s):  
Shape Memory Alloy ◽  
Theoretical Analysis ◽  
Shape Memory ◽  
Preliminary Analysis ◽  
Design Concept ◽  
Design Parameters ◽  
Sma Actuators ◽  
Fluid Analysis ◽  
Cold Fluid ◽  
Simulation And Experiment

This paper presents a conceptual design and preliminary analysis for a biomimetic robotic heart. The purpose of the robotic heart is to distribute hot and cold fluid to robotic muscles composed of wet shape-memory alloy (SMA) actuators. The robotic heart is itself powered by wet SMA actuators. A heart design concept is proposed and the feasibility of self-sustaining motion is investigated through simulation and experiment. The chosen design employs symmetric pumping chambers for hot and cold fluid. Analysis of this design concept shows that there exists a range of design parameters that will allow the heart to output more fluid than it uses. Additionally, it is shown that the heartbeat rate decreases as the system increases in size, and that the number of actuators and their length limit the power output of the pump. Experimental results from a prototype heart agree with the predicted trends from theoretical analysis and simulation.

A Novel Design of a Large-Stroke Shape Memory Alloy Linear Actuator

2019 ◽  
Author(s):  
Fei Yang ◽  
Jian Wang ◽  
Miaoling Han ◽  
Yifan Lu ◽  
Honghao Yue ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Linear Actuator ◽  
Confined Space ◽  
Output Displacement ◽  
Tandem Structure ◽  
In Series ◽  
Sma Actuator ◽  
Application Fields ◽  
Actuation Systems

Abstract The traditional actuation systems such as combustion engines, electro motors, hydraulic and pneumatic machines, have several drawbacks: large volume and weight, huge energy consumption and high cost. To overcome these problems, this paper presents a novel large-stroke linear actuator actuated by shape memory alloy (SMA) wires. Multiple SMA wires are distributed in the space three-dimensionally and connected in series to achieve a larger stroke of the actuator. The tandem structure makes the SMA actuator easy to integrate into a narrow available space with dimension constraints. A theoretical model for bias element selection is developed through analysis of the driving paths. A prototype of the proposed SMA actuator is fabricated and corresponding experiments are conducted to verify the functions and performances. The critical working performances of the SMA actuator such as the output displacement, heating electric current, actuation time and reset time are obtained and investigated. The results prove that the proposed SMA actuator can output an ideal driving stroke and enough actuation force in confined space. This research provides design ideas for the large-stroke SMA actuator in more application fields.

scholarly journals An analytical model for crack monitoring of the shape memory alloy intelligent concrete

2019 ◽  
Vol 31 (1) ◽  
pp. 100-116 ◽  
Author(s):  
Bingfei Liu ◽  
Qingfei Wang ◽  
Kai Yin ◽  
Liwen Wang
Keyword(s):  
Shape Memory Alloy ◽  
Constitutive Model ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Monitoring Model ◽  
Crack Monitoring ◽  
The One

A theoretical model for the crack monitoring of the shape memory alloy intelligent concrete is presented in this work. The mechanical properties of shape memory alloy materials are first given by the experimental test. The one-dimensional constitutive model of the shape memory alloys is reviewed by degenerating from a three-dimensional model, and the behaviors of the shape memory alloys under different working conditions are then discussed. By combining the electrical resistivity model and the one-dimensional shape memory alloy constitutive model, the crack monitoring model of the shape memory alloy intelligent concrete is given, and the relationships between the crack width of the concrete and the electrical resistance variation of the shape memory alloy materials for different crack monitoring processes of shape memory alloy intelligent concrete are finally presented. The numerical results of the present model are compared with the published experimental data to verify the correctness of the model.

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