| Introduction | p. 1 |
| Adaptive Structural Systems | p. 1 |
| Objective and Scope | p. 2 |
| Outline and Overview | p. 3 |
| Helicopter Applications | p. 5 |
| Noise and Vibration | p. 5 |
| Generation | p. 5 |
| Areas of Relevance | p. 7 |
| Main Rotor | p. 8 |
| Rotational Sources | p. 8 |
| Impulsive Sources | p. 9 |
| Broadband Sources | p. 10 |
| Passive Concepts | p. 10 |
| External Devices | p. 10 |
| Aeroelastic Conformability | p. 11 |
| Active and Adaptive Concepts | p. 13 |
| Pitch Control at the Blade Root | p. 13 |
| Discrete Flap Actuation | p. 14 |
| Integral Blade Actuation | p. 14 |
| Adaptive Beam Aspects | p. 15 |
| Beam Actuation Concepts | p. 16 |
| Adaptive System Concepts | p. 17 |
| Development Status | p. 17 |
| Fundamental Considerations | p. 19 |
| Mathematical Preliminaries | p. 19 |
| Euclidean Vectors | p. 19 |
| Tensor Representation | p. 20 |
| Matrix Representation | p. 21 |
| Deformable Structures-Mechanical Fields | p. 22 |
| Loads | p. 23 |
| Stresses | p. 23 |
| Mechanical Equilibrium | p. 24 |
| Strains | p. 25 |
| Transformations | p. 26 |
| Dielectric Domains-Electrostatic Fields | p. 28 |
| Electric Charge | p. 29 |
| Electric Flux Density | p. 29 |
| Electrostatic Equilibrium | p. 29 |
| Electric Field Strengths | p. 30 |
| Principle of Virtual Work | p. 31 |
| General Principle of Virtual Work | p. 31 |
| Principle of Virtual Displacements | p. 32 |
| Principle of Virtual Loads | p. 33 |
| Principle of Virtual Electric Potential | p. 34 |
| D'Alembert's Principle in the Lagrangian Version | p. 35 |
| Summation of Virtual Work Contributions | p. 37 |
| Other Variational Principles | p. 38 |
| Extended Dirichlet's Principle of Minimum Potential Energy | p. 38 |
| Extended General Hamilton's Principle | p. 39 |
| Piezoelectric Materials | p. 41 |
| Piezoelectric Effect | p. 41 |
| Historical Development | p. 41 |
| Crystal Structures | p. 42 |
| Constitutive Formulation | p. 45 |
| Mechanical Fields | p. 46 |
| Electrostatic Fields | p. 47 |
| Electromechanical Coupling | p. 48 |
| Spatial Rotation | p. 49 |
| Analogy of Electrically and Thermally Induced Deformations | p. 49 |
| Constitutive Examination | p. 50 |
| Constitutive Relation | p. 50 |
| Converse Piezoelectric Effect | p. 52 |
| Direct Piezoelectric Effect | p. 53 |
| Constitutive Reduction | p. 56 |
| Unidirectional Electrostatic Fields | p. 57 |
| Planar Mechanical Fields | p. 61 |
| Planar Rotation | p. 63 |
| Negated Electric Field Strength | p. 64 |
| Actuator and Sensor Conditions | p. 65 |
| Actuator Application with Voltage and Current Source | p. 65 |
| Sensor Application with Voltage and Current Measurement | p. 66 |
| Piezoelectric Composites | p. 69 |
| Classification of General Composites | p. 69 |
| Topology of the Inclusion Phase | p. 69 |
| Laminated Composites and Laminated Fiber Composites | p. 70 |
| Conception of Piezoelectric Composites | p. 70 |
| Interdigitated Electrodes and Piezoelectric Fibers | p. 71 |
| Electroding Implications | p. 72 |
| Development Status | p. 73 |
| Representative Volume Element and Fiber Geometry | p. 74 |
| Modeling Preliminaries | p. 77 |
| Micro-Electromechanics with Equivalent Inclusions | p. 77 |
| Mean Fields and Concentration Matrices | p. 78 |
| Elementary Rules of Mixture | p. 79 |
| Equivalence of Inclusion and Inhomogeneity | p. 79 |
| Non-Dilute Concentrations | p. 81 |
| Micro-Electromechanics with Sequential Stacking | p. 82 |
| Stacking of Constituents with Uniform Fields | p. 82 |
| Normal Mode Stacking Coefficients | p. 83 |
| Shear Mode Stacking Coefficients | p. 86 |
| Stacking Sequences | p. 87 |
| Non-Homogeneous Electrostatic Fields | p. 89 |
| Stacking Sequences for Non-Homogeneous Electrostatic Fields | p. 92 |
| Validation of the Micro-Electromechanics | p. 93 |
| Experiments and Finite Element Models | p. 94 |
| Dielectric, Piezoelectric, and Mechanical Properties | p. 95 |
| Adaptive Laminated Composite Shells | p. 99 |
| Macro-Electromechanics | p. 99 |
| Lamination Theory | p. 99 |
| Laminates with Groups of Electrically Paralleled Laminae | p. 101 |
| Kinematics and Equilibrium | p. 103 |
| General Thin Shell Kinematics | p. 103 |
| Cylindrical Thin Shell Kinematics | p. 104 |
| Cylindrical Thin Shell Equilibrium | p. 106 |
| Constitutive Reduction | p. 107 |
| Negligence of Strain and Stress Components | p. 107 |
| Potential Energy Considerations | p. 109 |
| Adaptive Thin-Walled Beams | p. 115 |
| General Beam Kinematics | p. 115 |
| Positions and Displacements | p. 115 |
| Rotations | p. 116 |
| Simplifications | p. 117 |
| Strains | p. 119 |
| Thin-Walled Beam Kinematics | p. 120 |
| Differential Geometry | p. 120 |
| Cartesian and Curvilinear Positions and Displacements | p. 121 |
| Strains of Wall and Beam | p. 123 |
| Electric Field Strength | p. 125 |
| Torsional Out-of-Plane Warping for Thin Walls | p. 126 |
| General Formulation | p. 126 |
| Non-Branched Open and Closed Cross-Sections | p. 128 |
| General Cross-Sections with Open Branches and Closed Cells | p. 130 |
| Exemplary Configurations | p. 132 |
| Consistency Contemplations | p. 134 |
| Rotating Beams | p. 136 |
| Rotor Kinematics | p. 136 |
| Transformation Properties | p. 137 |
| Virtual Work Statements | p. 139 |
| Internal Virtual Work | p. 139 |
| Internal Loads of Beam and Wall | p. 140 |
| Constitutive Relation | p. 140 |
| Constitutive Coefficients | p. 141 |
| Partially Prescribed Electric Potential | p. 146 |
| External Virtual Work | p. 147 |
| Applied Load Contributions | p. 148 |
| Inertia Load Contributions | p. 148 |
| Equilibrium and Boundary Contributions | p. 150 |
| Second-Order Theory | p. 151 |
| Additional Internal Load Contributions | p. 152 |
| Reformulation | p. 153 |
| Solution Variants | p. 155 |
| Statics of the Non-Rotating Structure | p. 155 |
| Configuration Restrictions | p. 155 |
| Extension, Torsion, and Warping Solution | p. 156 |
| Shear and Bending Solution | p. 159 |
| Dynamics of the Rotating Structure | p. 160 |
| Virtual Work Roundup | p. 160 |
| Finite Element Formulation | p. 161 |
| Solution | p. 165 |
| Demonstration and Validation | p. 169 |
| Beam Configurations | p. 169 |
| Actuation and Sensing Schemes | p. 169 |
| Set-Up of Walls | p. 172 |
| Set-Up of Cross-Sections | p. 174 |
| Constitutive Coefficients | p. 176 |
| Elementary Examinations | p. 178 |
| Beam Geometry Influences on the Actuation Schemes | p. 178 |
| Beam Property Adaptation | p. 180 |
| Wall Geometry Optimization | p. 182 |
| Validation and Evaluation | p. 187 |
| Reference Configurations | p. 187 |
| Reference Calculations | p. 189 |
| Static Behavior | p. 190 |
| Free Vibrations | p. 193 |
| Forced Vibrations | p. 197 |
| Conclusion | p. 199 |
| Summary | p. 199 |
| Perspective | p. 200 |
| Material Properties | p. 203 |
| Helicopter Rotor Properties | p. 205 |
| References | p. 207 |
| Index | p. 217 |
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