Sound and structural vibration radiationPDF电子书下载

1.Waves in Fluids and Solid Structures 1

1.1 Frequency and Wavenumber 1

1.2 Sound Waves in Fluids 8

1.3 Longitudinal Waves in Solids 11

1.4 Quasi-Longitudinal Waves in Solids 13

1.5 Transverse （Shear） Waves in Solids 14

1.6 Bending Waves in Bars 19

1.7 Bending Waves in Thin Plates 26

1.8 Dispersion Curves 27

1.9 Flexural Waves in Thin-Walled Circular Cylindrical Shells 30

1.10 Natural Frequencies and Modes of Vibration 38

1.11 Forced Vibration and Resonance 50

1.12 Modal Density and Modal Overlap 64

1.13 The Roles of Modal Density in Vibroacoustics 69

Problems 72

2 Structural Mobility，Impedance，Vibrational Energy and Power 75

2.1 Mobility and Impedance Representations 75

2.2 Concepts and General Forms of Mobility and Impedance of Lumped Mechanical Elements 79

2.3 Mobility Functions of Uniform Beams in Bending 84

2.3.1 Infinite Beam 84

2.3.2 Finite Beam （Closed Form） 87

2.3.3 Finite Beam （Modal Summation） 90

2.4 Mobility and Impedance Functions of Thin Uniform Flat Plates 102

2.4.1 Infinite Plate 102

2.4.2 Finite Plate 106

2.5 Radial Driving-Point Mobility of Thin-Walled Circular Cylindrical Shells 110

2.6 Mobility and Impedance Matrix Models 115

2.7 Structural Power 121

2.8 Energy Density and Energy Flux of Vibrational Waves 129

Problems 134

3. Sound Radiation by Vibrating Structures 135

3.1 The Importance and Mechanism of Sound Radiation by Vibrating Structures 135

3.2 The Simple Volume Source 138

3.3 Sound Radiation by a Pair of Elementary Surface Sources 141

3.4 The Baffled Piston 143

3.5 Sound Radiation by Flexural Modes of Plates 145

3.6 Sound Radiation by Plates in Multi-Mode Flexural Vibration 159

3.6.1 Formulation in Terms of Structural Modes 159

3.6.2 Formulation in Terms of Elementary Radiators 165

3.7 Independent Radiation Modes 168

3.7.1 Formulation in Terms of Structural Modes 169

3.7.2 Formulation in Terms of Elementary Radiators 170

3.7.3 Radiation Modes and Efficiencies 171

3.7.4 A Comparison of Self- and Mutual Radiation by Plate Modes 172

3.8 Sound Radiation by Flexural Waves in Plates 175

3.9 The Frequency-Average Radiation Efficiency of Plates 185

3.10 Sound Radiation due to Concentrated Forces and Displacements 195

3.11 Sound Radiation by Non-Uniform Plate Structures 204

3.11.1 Beam-Stiffened Plates 204

3.11.2 Corrugated Plates 209

3.11.3 Sandwich Plates 210

3.11.4 Composite Sound Insulation Panels 212

3.12 Sound Radiation by Curved Shells 213

3.13 Sound Radiation by Irregularly Shaped Vibrating Bodies 227

Problems 240

4.Fluid Loading of Vibrating Structures 243

4.1 Practical Aspects of Fluid Loading 243

4.2 Pressure Fields on Vibrating Surfaces 245

4.3 Wave Impedances of Structures and Fluids 256

4.4 Fluid Loading of Vibrating Plates 261

4.5 Natural Frequencies of Fluid-Loaded Plates 267

4.6 Effects of Fluid Loading on Sound Radiation from Point-Excited Plates 268

4.7 Natural Frequencies of Fluid-Loaded，Thin-Walled，Circular Cylindrical Shells 270

4.8 Effects of Fluid Loading on Sound Radiation by Thin-Walled，Circular Cylindrical Shells 270

4.9 Damping of Thin Plates by Porous Sheets 275

Problems 275

5.Transmission of Sound through Partitions 277

5.1 Practical Aspects of Sound Transmission through Partitions 277

5.2 Transmission of Normally Incident Plane Waves through an Unbounded Partition 278

5.3 Transmission of Obliquely Incident Plane Waves through an Unbounded Flexible Partition 284

5.4 Transmission of Diffuse Sound through a Bounded Partition in a Baffle 296

5.5 Transmission of Sound through a Partition between Two Rooms 299

5.6 Double-Leaf Partitions 303

5.7 Transmission of Normally Incident Plane Waves through an Unbounded Double-Leaf Partition 304

5.8 The Theoretical Effect of Cavity Sound Absorption on Normal Incidence Transmission Loss 310

5.9 Transmission of Obliquely Incident Plane Waves through an Unbounded Double-Leaf Partition 314

5.10 Mechanical Stiffening and Coupling of Double Partition Leaves 323

5.11 Close-Fitting Enclosures 330

5.12 Transmission of Sound through Stiffened，Composite，Multilayer and Non-Uniform Panels 337

5.13 Transmission of Sound through Circular Cylindrical Shells 352

5.14 Coupling between Shell Modes and Acoustic Modes of a Contained Fluid 353

5.15 Vibrational Response of Pipes to Internal Acoustic Excitation 358

5.16 Transmission of Internally Generated Sound through Pipe Walls 364

5.17 Transmission of Externally Incident Sound through Large-Diameter，Thin-Walled Cylinders 366

Problems 372

6.Acoustically Induced Vibration of Structures 375

6.1 Practical Aspects of Acoustically Induced Vibration 375

6.2 Decomposition of a Sound Field 376

6.3 Response of a Baffled Plate to Plane Sound Waves 379

6.4 The Principle of Vibroacoustic Reciprocity 385

6.5 Modal Reciprocity：Radiation and Response 386

6.6 Radiation Due to Point Forces and Response to Point Sources 391

6.7 An Application of Response Theory to Building Acoustics 396

Problems 400

7.Acoustic Coupling between Structures and Enclosed Volumes of Fluid 403

7.1 Practical Importance of the Problem 403

7.2 A Simple Case of Fluid-Structure Interaction 404

7.3 Harmonic Sound Fields in an Enclosed Volume of Fluid 408

7.4 Sound Field in a Closed Space with Rigid Surfaces 414

7.5 Interaction Analysis by Green’s Function 415

7.6 Modal-Interaction Model 418

7.7 Solutions of the Modal-Interaction Model 422

7.8 Power Flow and Statistical Energy Analysis 427

7.9 Wave Propagation in Plates Loaded by Confined Fluid Layers 433

7.10 Wave Propagation in Fluid-Filled Tubes of Circular Cross Section 443

Problems 447

8.Introduction to Numerically Based Analyses of Fluid-Structure Interaction 449

8.1 The Role of Numerical Analysis 449

8.2 Numerical Analysis of Vibration in Solids and Fluids 451

8.3 Finite Element Analysis 453

8.4 Finite Element Analysis of Vibrations in Solid Structures 455

8.4.1 Flexural Vibration of Slender Beams：Rayleigh-Ritz Method 456

8.4.2 Flexural Vibration of Slender Beams：Finite Element Analysis 461

8.4.3 Flexural Vibration of Thin Flat Plates：Finite Element Analysis 470

8.4.4 Finite Element Models for Other Types of Structure 478

8.5 Finite Element Analysis of Acoustic Vibrations of Fluids in Cavities 479

8.5.1 One-Dimensional Acoustic Vibration of a Fluid in a Uniform Straight Pipe：Rayleigh-Ritz Method 480

8.5.2 One-Dimensional Acoustic Vibration of Fluid in a Uniform Straight Pipe：Finite Element Analysis 484

8.5.3 Acoustic Vibration of a Fluid in a Three-Dimensional Cavity：Finite Element Analysis 489

8.6 Coupled Fluid-Structure Analysis 496

8.7 Boundary Element Analysis for Vibroacoustic Problems 503

8.7.1 Direct Boundary Element Method 505

8.8 Coupled Structure-Fluid Analysis 515

Problems 519

9.Introduction to Active Control of Sound Radiation and Transmission 521

9.1 Introduction to Active Control 521

9.2 Fundamentals of Active Control Theory 522

9.2.1 Feed-Forward Control 523

9.2.2 Feedback Control 532

9.3 Sensor-Actuator Transducers 548

9.3.1 Strain Actuators 549

9.3.2 Inertial Electrodynamic Actuators 555

9.3.3 Strain Sensors 561

9.3.4 Inertial Sensors （Accelerometers） 565

9.4 From Active Noise Control to Active Structural Acoustic Control and Active Vibration Control 569

9.4.1 Feed-Forward Active Noise Control and Active Noise-Vibration Control 570

9.4.2 Feed-Forward Active Structural Acoustic Control 573

9.4.3 Feedback Active Structural Acoustic Control 575

9.4.4 Decentralised Feedback Active Vibration Control 576

9.5 Smart Panels for ASAC and AVC Systems 580

9.5.1 Models of Smart Panels 580

9.5.2 Smart Panels with Feed-Forward MIMO and SISO Control Systems 584

9.5.3 Smart Panel with Feed-Forward SISO Control Systems Using a Volume Velocity Distributed Sensor and Uniform Force Distributed Actuator 588

9.5.4 Smart Panels with Feedback MIMO and SISO Control Systems 590

9.5.5 Smart Panel with a Feedback SISO Control System Using a Volume Velocity Sensor and Uniform Force Actuator 595

Problems 596

Answers 597

References 607

Index 621