Handbook of Compliant Mechanisms

A fully illustrated reference book giving an easy-to-understand introduction to compliant mechanisms

A broad compilation of compliant mechanisms to give inspiration and guidance to those interested in using compliant mechanisms in their designs, the Handbook of Compliant Mechanisms includes graphics and descriptions of many compliant mechanisms. It comprises an extensive categorization of devices that can be used to help readers identify compliant mechanisms related to their application. It also provides chapters on the basic background in compliant mechanisms, the categories of compliant mechanisms, and an example of how the Compendium can be used to facilitate compliant mechanism design.

• Fully illustrated throughout to be easily understood and accessible at introductory levels

• Covers all aspects pertaining to classification, elements, mechanisms and applications of compliant mechanisms

• Summarizes a vast body of knowledge in easily understood diagrams and explanations

• Helps readers appreciate the advantages that compliant mechanisms have to offer

• Practical approach is ideal for potential practitioners who would like to realize designs with compliant mechanisms, members and elements

• Breadth of topics covered also makes the book a useful reference for more advanced readers

Intended as an introduction to the area, the Handbook avoids technical jargon to assist non engineers involved in product design, inventors and engineers in finding clever solutions to problems of design and function.

Auteur

Editors
LARRY L. HOWELL and SPENCER P. MAGLEBY, Brigham Young University, USA
BRIAN M. OLSEN, Los Alamos National Laboratory, USA

Contenu

List of Contributors xi

Acknowledgments xv

Preface xvii

Part One Introduction to Compliant Mechanisms

1 Introduction to Compliant Mechanisms 3

1.1 What are Compliant Mechanisms? 3

1.2 What are the Advantages of Compliant Mechanisms? 6

1.3 What Challenges do Compliant Mechanisms Introduce? 6

1.4 Why are Compliant Mechanisms Becoming More Common? 7

1.5 What are the Fundamental Concepts that Help Us Understand Compliance? 8

1.5.1 Stiffness and Strength are NOT the Same Thing 8

1.5.2 It is Possible for Something to be Flexible AND Strong 8

1.5.3 The Basics of Creating Flexibility 10

1.6 Conclusion 13

References 13

2 Using the Handbook to Design Devices 15

2.1 Handbook Outline 16

2.2 Considerations in Designing Compliant Mechanisms 16

2.3 Locating Ideas and Concepts in the Library 19

2.4 Modeling Compliant Mechanisms 20

2.5 Synthesizing Your Own Compliant Mechanisms 21

2.6 Summary of Design Approaches for Compliant Mechanisms 22

Further Reading 24

Part Two Modeling of Compliant Mechanisms

3 Analysis of Flexure Mechanisms in the Intermediate Displacement Range 29

3.1 Introduction 29

3.2 Modeling Geometric Nonlinearities in Beam Flexures 31

3.3 Beam Constraint Model 34

3.4 Case Study: Parallelogram Flexure Mechanism 38

3.5 Conclusions 41

Further Reading 42

4 Modeling of Large Deflection Members 45

4.1 Introduction 45

4.2 Equations of Bending for Large Deflections 46

4.3 Solving the Nonlinear Equations of Bending 47

4.4 Examples 48

4.4.1 Fixed-Pinned Beam 48

4.4.2 Fixed-Guided Beam (Bistable Mechanism) 49

4.5 Conclusions 52

Further Reading 53

References 53

5 Using Pseudo-Rigid Body Models 55

5.1 Introduction 55

5.2 Pseudo-Rigid-Body Models for Planar Beams 57

5.3 Using Pseudo-Rigid-Body Models: A Switch Mechanism Case-Study 60

5.4 Conclusions 65

Acknowledgments 65

References 65

Appendix: Pseudo-Rigid-Body Examples (by Larry L. Howell) 66

A.1.1 Small-Length Flexural Pivot 66

A.1.2 Vertical Force at the Free End of a Cantilever Beam 67

A.1.3 Cantilever Beam with a Force at the Free End 67

A.1.4 Fixed-Guided Beam 69

A.1.5 Cantilever Beam with an Applied Moment at the Free End 70

A.1.6 Initially Curved Cantilever Beam 70

A.1.7 Pinned-Pinned Segments 71

A.1.8 Combined Force-Moment End Loading 73

A.1.9 Combined Force-Moment End Loads 3R Model 74

A.1.10 Cross-Axis Flexural Pivot 74

A.1.11 Cartwheel Flexure 76

References 76

Part Three Synthesis of Compliant Mechanisms

6 Synthesis through Freedom and Constraint Topologies 79

6.1 Introduction 79

6.2 Fundamental Principles 82

6.2.1 Modeling Motions using Screw Theory 82

6.2.2 Modeling Constraints using Screw Theory 84

6.2.3 Comprehensive Library of Freedom and Constraint Spaces 86

6.2.4 Kinematic Equivalence 86

6.3 FACT Synthesis Process and Case Studies 87

6.3.1 Flexure-Based Ball Joint Probe 87

6.3.2 X-Y-ThetaZ Nanopositioner 88

6.4 Current and Future Extensions of FACT's Capabilities 89

Acknowledgments 90

References 90

7 Synthesis through Topology Optimization 93

7.1 What is Topology Optimization? 93

7.2 Topology Optimization of Compliant Mechanisms 95

7.3 Ground Structure Approach 98

7.4 Continuum Approach 100

7.4.1 SIMP Method 100 7.4.2 Homogenization Method 103</p&...