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, theHandbook 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 theCompendium can be used to facilitate compliant mechanism design.
Fully illustrated throughout to be easily understood and accessible at introductory levelsCovers all aspects pertaining to classification, elements, mechanisms and applications of compliant mechanismsSummarizes a vast body of knowledge in easily understood diagrams and explanationsHelps readers appreciate the advantages that compliant mechanisms have to offerPractical approach is ideal for potential practitioners who would like to realize designs with compliant mechanisms, members and elementsBreadth of topics covered also makes the book a useful reference for more advanced readers
Intended as an introduction to the area, theHandbook avoids technical jargon to assist non engineers involved in product design, inventors and engineers in finding clever solutions to problems of design and function.
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 (byLarry 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
6.3.2X-Y-ThetaZNanopositioner 88
6.4 Current and Future Extensions of FACTs 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
7.5 Discussion 104
7.6 Optimization Solution Algorithms 105
Acknowledgment 106
References 106
8 Synthesis through Rigid-Body Replacement 109
8.1 Definitions, Motivation, and Limitations 109
8.2 Procedures for Rigid-Body Replacement 111
8.2.1 Starting with a Rigid-Body Mechanism 111
8.2.2 Starting with a Desired Task 114
8.2.3 Starting with a Compliant Mechanism Concept 115
8.2.4 How DoWe Choose the Best Configurations Considering Loads, Strains, and Kinematics? 116
8.3 Simple Bicycle Derailleur Example 116
References 121
9 Synthesis through Use of Building Blocks 123
9.1 Introduction 123
9.2 General Building-Block Synthesis Approach 123
9.3 Fundamental Building Blocks 124
9.3.1 Compliant Dyad 124
9.3.2 Compliant 4-Bar 125
9.4 Elastokinematic Representations to Model Functional Behavior 125
9.4.1 Compliance Ellipses and Instant Centers 126
9.4.2 Compliance Ellipsoids 127
9.4.3 Eigentwist and Eigenwrench Characterization 130
9.5 Decomposition Methods and Design Examples 134
9.5.1 Single-Point Mechanisms 135
9.5.2 Multi-Port Mechanisms using Compliance Ellipsoids 139
9.5.3 Displacement Amplifying Mechanisms using Instant Centers 143
9.6 Conclusions 145
Further Reading 145
References 146
Part Four Library of Compliant Mechanisms
10 Library Organization 149
10.1 Introduction 149
10.1.1 Categorization 149
10.2 Library of Compliant Designs 151
10.3 Conclusion 153
References 153
11 Elements of Mechanisms 155
11.1 Flexible Elements 155
11.1.1 Beams 155
11.1.2 Revolute 161
11.1.3 Translate 179
11.1.4 Universal 181
11.2 Rigid-Link Joints 186
11.2.1 Revolute 186
11.2.2 Prismatic 187
11.2.3 Universal 188
11.2.4 Others 189
References 191
12 Mechanisms 193
12.1 Basic Mechanisms 193
12.1.1 Four-Bar Mechanism 193
12.1.2 Six-Bar Mechanism 195
12.2 Kinematics 197
12.2.1 Translational 197
12.2.2 Rotational 204
12.2.3 TranslationRotation 209
12.2.4 Parallel Motion 214
12.2.5 Straight Line 218
12.2.6 Unique Motion Path 220
12.2.7 Stroke Amplification 227
12.2.8 Spatial Positioning 230
12.2.9 Metamorphic 233
12.2.10 Ratchet 237
12.2.11 Latch 241
12.2.12 Others 243
12.3 Kinetics 245
12.3.1 Energy Storage 245
12.3.2 Stability 252
12.3.3 Constant Force 262
12.3.4 Force Amplification 263
12.3.5 Dampening 267
12.3.6 Mode 268
12.3.7 Others 269
References 272
13 Example Application 277
13.1 Elements of Mechanisms: Flexible Elements 277
13.2 Mechanisms: Kinematic 282
13.3 Mechanisms: Kinetic 291
References 317
Index 319
