Adaptive Structures

Adaptive structures have the ability to adapt, evolve or change their properties or behaviour in response to the environment around them. The analysis and design of adaptive structures requires a highly multi-disciplinary approach which includes elements of structures, materials, dynamics, control, design and inspiration taken from biological systems. Development of adaptive structures has been taking place in a wide range of industrial applications, but is particularly advanced in the aerospace and space technology sector with morphing wings, deployable space structures; piezoelectric devices and vibration control of tall buildings.

Bringing together some of the foremost world experts in adaptive structures, this unique text:

• includes discussions of the application of adaptive structures in the aerospace, military, civil engineering structures, automotive and MEMS.

• presents the impact of biological inspiration in designing adaptive structures, particularly the use of hierarchy in nature, which typically induces multi-functional behavior.

• sets the agenda for future research in adaptive structures in one distinctive single volume.

Adaptive Structures: Engineering Applications is essential reading for engineers and scientists working in the fields of intelligent materials, structural vibration, control and related smart technologies. It will also be of interest to senior undergraduate and postgraduate research students as well as design engineers working in the aerospace, mechanical, electrical and civil engineering sectors.

Auteur
The Editors are from the Departments of Aerospace and Mechanical Engineering at the University of Bristol. Friswell is the Sir George White Professor of Aerospace Engineering and currently a Royal Society-Wolfson Research Merit Award Holder. Bond, Drinkwater, Wagg and Weaver are all currently EPSRC Advanced Research Fellows. The editors have significant publication records in areas related to adaptive structures, which can be viewed from here: http://www.men.bris.ac.uk/ and http://www.aer.bris.ac.uk/. They are all involved in a significant amount of funded research projects (see http://www.epsrc.ac.uk/) for example the new Bristol Laboratories for Advanced Dynamic Engineering (BLADE) funded by a recent £15 million JIF award (GR/R51261/01) as well as numerous other research projects funded by the EPRSC and industry. Inman is the George R. Goodson Professor of Mechanical Engineering, and Director of the Center for Intelligent Material Systems and Structures at Virginia Tech, USA. He is also the Benjamin Meaker Visiting Professor at Bristol.

Contenu

List of Contributors xi

Preface xvii

1 Adaptive Structures for Structural Health Monitoring 1
Daniel J. Inman and Benjamin L. Grisso

1.1 Introduction 1

1.2 Structural Health Monitoring 4

1.3 Impedance-Based Health Monitoring 6

1.4 Local Computing 8

1.5 Power Analysis 11

1.6 Experimental Validation 13

1.7 Harvesting, Storage and Power Management 18

1.7.1 Thermal Electric Harvesting 19

1.7.2 Vibration Harvesting with Piezoceramics 22

1.8 Autonomous Self-healing 25

1.9 The Way Forward: Autonomic Structural Systems for Threat Mitigation 27

1.10 Summary 29

Acknowledgements 30

References 30

2 Distributed Sensing for Active Control 33
Suk-Min Moon, Leslie P. Fowler and Robert L. Clark

2.1 Introduction 33

2.2 Description of Experimental Test Bed 35

2.3 Disturbance Estimation 36

2.3.1 Principal Component Analysis 36

2.3.2 Application of PCA: Case Studies 37

2.3.3 Combining Active Control and PCA to Identify Secondary Disturbances 40

2.4 Sensor Selection 43

2.4.1 Model Estimation 45

2.4.2 Optimal Sensor Strategy 45

2.4.3 Experimental Demonstration 48

2.5 Conclusions 55

Acknowledgments 56

References 56

3 Global Vibration Control Through Local Feedback 59
Stephen J. Elliott

3.1 Introduction 59

3.2 Centralised Control of Vibration 61

3.3 Decentralised Control of Vibration 63

3.4 Control of Vibration on Structures with Distributed Excitation 67

3.5 Local Control in the Inner Ear 76

3.6 Conclusions 84

Acknowledgements 85

References 85

4 Lightweight Shape-Adaptable Airfoils: A New Challenge for an Old Dream 89
L.F. Campanile

4.1 Introduction 89

4.2 Otto Lilienthal and the Flying Machine as a Shape-Adaptable Structural System 91

4.3 Sir George Cayley and the Task Separation Principle 93

4.4 Being Lightweight: A Crucial Requirement 95

4.5 Coupling Mechanism and Structure: Compliant Systems as the Basis of Lightweight Shape-Adaptable Systems 104

4.5.1 The Science of Compliant Systems 104

4.5.2 Compliant Systems for Airfoil Shape Adaptation 113

4.5.3 The Belt-Rib Airfoil Structure 115

4.6 Extending Coupling to the Actuator System: Compliant Active Systems 118

4.6.1 The Need for a Coupled Approach 118

4.6.2 Solid-State Actuation for Solid-State Deformability 120

4.6.3 Challenges and Trends of StructureActuator Integration 123

4.7 A Powerful Distributed Actuator: Aerodynamics 125

4.7.1 The Actuator Energy Balance 125

4.7.2 Balancing Kinematics by Partially Recovering Energy from the Flow 125

4.7.3 Active and Semi-Active Aeroelasticity 126

4.8 The Common Denominator: Mechanical Coupling 127

4.9 Concluding Remarks 128

Acknowledgements 129

References 129

5 Adaptive Aeroelastic Structures 137
Jonathan Cooper

5.1 Introduction 137

5.2 Adaptive Internal Structures 142

5.2.1 Moving Spars 143

5.2.2 Rotating Spars 147

5.3 Adaptive Stiffness Attachments 152

5.4 Conclusions 159

5.5 The Way Forward 160

Acknowledgements 161

References 162

6 Adaptive Aerospace Structures with Smart Technologies A Retrospective and Future View 163
Christian Boller

6.1 Introduction 163

6.2 The Past Two Decades 165

6.2.1 SHM 167

6.2.2 Shape Control and Active Flow 170

6.2.3 Damping of Vibration and Noise 173

6.2.4 Smart Skins 176

6.2.5 Systems 177 6.3 Added Value to the System 179</p&g...