Design of Shape Memory Alloy (SMA) Actuators

Preface

Acknowledgments

Contents

1 Introduction to Shape Memory Alloys

1.1 Smart Materials--An Overview

1.2 Smart Structures---System Level Response

1.3 Shape Memory Alloys: Temperature Induced Phase Transformations

1.4 Shape Memory Effect and Superelasticity/Pseudoelasticity

1.5 Commonly Used Shape Memory Alloys

1.6 SMA Applications: Overview

1.6.1 Biomedical Applications

1.6.2 Civil Engineering Applications

1.6.3 Aerospace and Automotive Applications

1.6.4 Miscellaneous Applications

1.7 Chapter Summary

References

2 Need and Functionality Analysis

2.1 The System Design Process

2.1.1 Design Methodology: Structure and Guidelines

2.2 The Five Major Subsystems

2.3 How Do We Identify Need and Functionality for SMAs

References

3 Manufacturing and Post Treatment of SMA Components

3.1 Different Manufacturing Techniques

3.1.1 Vacuum Induction Melting (VIM) Technique

3.1.2 Vacuum Arc Remelting (VAR) Technique

3.1.3 Electronic Beam Melting (EBM) Technique

3.1.4 Conventional/Normal Sintering Technique

3.1.5 Selective Laser Sintering (SLS)

3.1.6 Hot Isotactic Pressing (HIP)

3.1.7 Spark Plasma Sintering (SPS)

3.1.8 Selective Laser Melting (SLM)

3.1.9 Metal Injection Molding (MLM)

3.2 Post Treatment of SMAs

3.2.1 Machining of SMA Components

3.2.2 Surface Treatment of SMA Components

3.2.3 Annealing and Coldworking of SMA

3.2.4 Joining of SMA to Itself and Other Materials Like Stainless Steel

3.2.5 Shape Setting of Nitinol

References

4 Basic SMA Component Geometries and Responses

4.1 SMA Wire Response---Tensile Loading

4.2 SMA Wire Response---Torsional Loading

4.3 SMA Spring Response---Torsional Loading

References

5 Factors Influencing Design of SMA Actuators

5.1 Geometry Factors

5.2 Effect of Alloy Composition

5.3 Effect of Shape Setting Conditions for Custom Shape (Making SMA Springs)

5.4 Effect of Operating Temperature on Mechanical Response

5.5 Effect of Loading Rates

5.6 Wire Training/Hysteresis Stabilization

References

6 Graphical Description of Temperature Controlled Actuation of SMA Wires

6.1 SMA Wire + Bias Spring Arrangement

6.1.1 SMA Wire Selection

6.1.2 Operating Temperature of SMA Wire

6.2 Graphical Design Approach for Stroke Estimation

6.2.1 Graphical Design Approach for Stroke Estimation---Load and Displacement Controlled Tests

6.2.2 SMA Wire + Bias Spring: Graphical Design Approach for Stroke Estimation Using Linearized Loading Response only

6.3 Case Study 2: Linear to Rotary Arrangement Using a SMA Wire + Bias Spring Arrangement Using Linearized Loading Response Only

6.4 Case Study 3: SMA Wire + Bias Spring Arrangement Using Linearized Loading---Unloading Response

6.5 Case Study 4: SMA Wire + Bias Spring Arrangement ƒ

References

7 Case Studies in the Preliminary Design of SMA Actuators

7.1 Different Modes of Operation

7.1.1 Constant Force Mode

7.1.2 Constant Deflection Mode

7.1.3 Simultaneous Force-Deflection Mode

7.2 Design of SMA Wires Under Constant Force

7.3 Case Study II: Design Procedure for Ti--Ni (SMA) Springs

7.4 Spring Design Case Study

7.4.1 Design Model and Assumptions

7.4.2 Terms Used in Design of SMA Springs

7.5 Example: Design of a Remote Controlled Flow Control Valve Using an SMA

7.5.1 Statement of Requirement

7.6 Extensional Spring Design

7.7 Heating and Cooling of Shape Memory Wires

7.7.1 Time Taken to Heat Up and Cool Down

References

8 Coupling SMA Actuators with Mechanisms: Principle of Virtual Work

8.1 The Need for Mechanisms

8.2 The Loading Curve and the SMA Response

8.3 3-D Design

8.4 Bias Forces

Reference

9 Fatigue of SMAs

9.1 Structural and Functional Fatigue in SMAs

9.2 Reporting Fatigue Data

References