Elastic Waves in Solids, Volume 2: Radiation, Scattering, Generation

Elastic waves are used in fields as diverse as the non-destructive evaluation of materials, medicine, seismology and telecommunications.  Elastic Waves in Solids 2 analyzes the radiation, scattering and generation of these waves. It studies the emission of bulk or surface waves from sources localized on the surface of an isotropic or anisotropic solid. It then examines the scattering of a longitudinal or transverse elastic wave by one or more cylindrical or spherical heterogeneities. Finally, it explores the methods and devices used to generate and detect elastic waves, using the piezoelectric effect or the interaction with a laser beam. Accompanying figures illustrate these properties, and the text provides the orders of magnitude of some characteristic parameters. This book is intended for students completing a master’s degree in acoustics, mechanics, geophysics or engineering, as well as teachers and researchers in these disciplines.

Table of Contents:
Preface vii List of Main Symbols xi Chapter 1. Radiation of Elastic Waves 1 1.1. Acoustic radiation in a fluid 1 1.1.1. Integral formulation of the Helmholtz equation 3 1.1.2. Rayleigh integral 5 1.1.3. Rayleigh–Sommerfeld integral 8 1.1.4. Harmonic case 8 1.1.5. Impulse diffraction 20 1.2. Generation of elastic waves by a surface source 32 1.2.1. Solid with orthotropic symmetry 34 1.2.2. Far field 36 1.2.3. Generation in a plate 48 1.3. Radiation of elementary spherical sources 52 1.3.1. Pulsating sphere 53 1.3.2. Oscillating sphere with a rotational motion 54 1.3.3. Oscillating sphere with a translational motion 55 Chapter 2. Scattering of Elastic Waves 59 2.1. Acoustic scattering by an immersed cylinder 63 2.1.1. Scattering by a rigid cylinder 65 2.1.2. Scattering by an elastic cylinder 68 2.1.3. Circumferential waves 71 2.2. Scattering of elastic waves by a cylinder 73 2.3. Scattering of elastic waves by a spherical particle 77 2.3.1. General formulation of the problem 77 2.3.2. Scattering of a longitudinal plane wave 78 2.3.3. Scattering of a transverse plane wave 85 2.4. Scattering by a set of particles 92 2.4.1. Scalar theory of multiple scattering 93 2.4.2. Velocity and attenuation of coherent waves 100 Chapter 3. Generation and Detection 105 3.1. Piezoelectric transducer for bulk waves 106 3.1.1. Materials and structures 106 3.1.2. One-dimensional model, equivalent circuits 110 3.1.3. Frequency and impulse responses – emitted power 117 3.1.4. Electrical impedance, efficiency 122 3.2. Piezoelectric transducer for surface waves 125 3.2.1. Operating principle 126 3.2.2. Impulse response model 132 3.2.3. Three-port circuit (hexapole): scattering matrix 139 3.2.4. Coupled modes method 143 3.3. Generation by laser impact 154 3.3.1. Thermoelastic regime 156 3.3.2. Ablation regime 166 3.4. Optical measurement of mechanical displacements 169 3.4.1. Non-interferometric methods 169 3.4.2. Interferometric methods 172 3.4.3. Doppler velocimetry 177 3.4.4. Picosecond acoustics 181 Appendix 1 185 Appendix 2 195 References 201 Index 207