Scattering of Acoustic and Elastic Waves by Surfaces of Arbitrary Shape PDF Download

Author: Robert Peter Banaugh
Publisher:
ISBN:
Category : Elastic waves
Languages : en
Pages : 196

View

Book Description

Author: Richard Paul Shaw
Publisher:
ISBN:
Category : Elastic waves
Languages : en
Pages : 17

View

Book Description
The scattering of elastic waves by rigid obstacles of arbitrary shape is discussed in terms of an integro-differential equation similar to Kirchoff's equation. This approach has proved valuable in the treatment of acoustic scattering problems and the extension proposed is relatively straightforward. The advantage of this approach is that the problem can be formulated completely in terms of surface values of stress and strain thereby reducing the order of magnitude of the problem. From a numerical point of view this is a significant economy. Field values can be obtained from the surface values by a direct quadrature if required. A simple problem is discussed as an example of the procedure. More complicated problems are being considered as well as extensions of this approach to other boundary conditions (e.g. free, discontinuity in elastic properties, etc.). (Author).

Author: Bo A. Peterson
Publisher:
ISBN:
Category :
Languages : en
Pages : 44

View

Book Description
A scattering or T-matrix approach is presented for studying the scattering of acoustic waves by elastic and viscoelastic obstacles immersed in a fluid. A Kelvin-Voigt model is used to obtain the complex elastic moduli of the viscoelastic solid. The T-matrix formulation is somewhat complicated because the wave equations and fields are quite different in the solid and fluid regions and are coupled by continuity conditions at the interface. We have obtained fairly extensive numerical results for prolate and oblate spheroids for a variety of scattering geometries. The backscattering, bistatic, absorption and extinction cross-section are presented as a function of the frequency of the incident wave. (Author).

Author: Claude Bourrely
Publisher: World Scientific
ISBN: 981461887X
Category :
Languages : en
Pages : 374

View

Book Description
Contents:Light Scattering Problems in Astrophysics (J M Perrin)Surface Integral Operators and their Use in Acoustics and Electromagnetics (A Berthon)Acoustic Diffraction by Slender Bodies of Arbitrary Shape (M Tran-Van-Nhieu)High and Low Energy Approximations for the Electromagnetic Scattering by Irregular Objects (B Torresani)Electromagnetic Scattering and Mutual Interactions Between Closely Spaced Spheroids (J Dalmas & R Deleuil)Acoustical Imaging of 2D Fluid Targets Buried in a Half Space: A Diffraction Tomography Approach Using Line-Sources Insonification (B Duchene et al)Contribution of Radar Polarimetry in Radar Target Discrimination. The “Poincaré Planisphere”: a New Representation Method (E Pottier)Electromagnetic and Acoustic Waves in Random Media: from Propagation to Anderson Localization (B Souillard)Weak Disorder: Homogeneisation Method and Propagation (C Bardos)Coherent Propagation of Surface Acoustic Waves in Quasi-Periodic and Random Arrays of Grooves (D Sornette et al)On Asymptotic Behaviour of Waves States in Random Media (F Bentosela & R Rodriguez)A Study of Acoustic Transmission of Transient Signal in a Inhomogeneous Medium with the Help of a Wavelet Transform. Application to an Air-Water Plane Interface (G Saracco & Ph Tchamitchian)Three-Dimensional Impedance Scattering Theory (P Sabatier)Survey of Optimization Algorithms Applied to Inverse Problems (A Roger)A Linearized Inverse Problem: Acoustic Impedance Tomography of Biological Media (J P Lefebvre)and others Readership: Electrical engineers and mathematicians.

Author: Ronald P. Radlinski
Publisher:
ISBN:
Category :
Languages : en
Pages : 18

View

Book Description
An acoustic scattering formulation has been derived from a modification of the extended boundary integral method developed for elastic wave scattering from infinite cylindrical shells of arbitrary shape. The boundary condition of no tangential component of surface traction at the fluid-shell interface allows a simplification of the thin shell equations assumed to describe the motion of the scatterer. Expansion of the normal and tangential displacements of the shell into Fourier series which are a function of arc length reduces the shell equations to algebraic form. For this presentation the geometry is specialized to elliptical shells. Results are presented for shells of different materials and eccentricities. Comparisons are made between acoustic scattering and elastic p-p wave scattering. At low frequencies, modal resonances dominate the response of the shell in fluid. In an elastic medium, the modal response at the shell is reduced. At higher frequencies, creeping waves are generated for particular angles of incident.

Author: V. K. Varadan
Publisher: Pergamon
ISBN:
Category : Science
Languages : en
Pages : 712

View

Book Description

Author: Allan D. Pierce
Publisher: Academic Press
ISBN: 1483257762
Category : Technology & Engineering
Languages : en
Pages : 395

View

Book Description
Underwater Scattering and Radiation describes the relevant theoretical foundations of underwater scattering and radiation. Acoustic scattering from elastic solids is discussed, and variational formulations in acoustic radiation and scattering are presented. Surface waves and quasi-cylindrical modes are also explored, along with the Helmholtz-Kirchhoff integral corollaries. Comprised of two chapters, this volume begins with a comprehensive account of scattering by elastic objects, focusing on the classic idealized shapes of spheres and infinite cylinders. The reader is introduced to important concepts such as normal modes, the S-matrix, and the T-matrix as well as resonances, whispering gallery modes, Franz modes, and Stoneley waves. Subsequent sections describe methods for treating scattering by elastic bodies of more general shapes. The T-matrix formalism is discussed and then applied to spheroidal scatterers and finite cylinders. The second chapter analyzes how variational principles can be used in acoustics, with the choice of topics directed toward applications to underwater acoustic radiation and scattering. This book will be of interest to physicists.

Author: Alexander G. Ramm
Publisher: World Scientific
ISBN: 9812561862
Category : Technology & Engineering
Languages : en
Pages : 314

View

Book Description
This book presents analytical formulas which allow one to calculate the S-matrix for the acoustic and electromagnetic wave scattering by small bodies or arbitrary shapes with arbitrary accuracy. Equations for the self-consistent field in media consisting of many small bodies are derived. Applications of these results to ultrasound mammography and electrical engineering are considered.The above formulas are not available in the works of other authors. Their derivation is based on a mathematical theory for solving integral equations of electrostatics, magnetostatics, and other static fields. These equations are at a simple characteristic value. Convergent iterative processes are constructed for stable solution of these equations. The theory completes the classical work of Rayleigh on scattering by small bodies by providing analytical formulas for polarizability tensors for bodies of arbitrary shapes.

Author: Karl F. Graff
Publisher: Courier Corporation
ISBN: 0486139573
Category : Science
Languages : en
Pages : 690

View

Book Description
Self-contained coverage of topics ranging from elementary theory of waves and vibrations in strings to three-dimensional theory of waves in thick plates. Over 100 problems.

Author: Georgia Lynott
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description