Transient Waves in Visco-Elastic Media


Book Description

Developments in Solid Earth Geophysics 10: Transient Waves in Visco-Elastic Media deals with the propagation of transient elastic disturbances in visco-elastic media. More specifically, it explores the visco-elastic behavior of a medium, whether gaseous, liquid, or solid, for very-small-amplitude disturbances. This volume provides a historical overview of the theory of the propagation of elastic waves in solid bodies, along with seismic prospecting and the nature of seismograms. It also discusses the seismic experiments, the behavior of waves propagated in accordance with the Stokes wave equation, and wavelet functions and their polynomials. The book explains the laws of propagation of seismic wavelets and seismic ray paths, as well as the equations of wavelet propagation, the velocity-type seismic wavelet, and the spectrum of the wavelet. It discusses the motion of a mechanical seismograph disturbed by extraneous forces or motions. It also provides information on the differential equation describing the motion of a galvanometer, laboratory studies of wavelet contraction, and characteristics of a wavelet-contractor amplifier. Furthermore, the book explains the experimental studies of the primary seismic disturbance and internal friction. This monograph is a valuable source of information for physicists, students who want to pursue a career in geophysics or selenophysics, and those who actively working in these fields.




Elastic wave propagation in transversely isotropic media


Book Description

In this monograph I record those parts of the theory of transverse isotropic elastic wave propagation which lend themselves to an exact treatment, within the framework of linear theory. Emphasis is placed on transient wave motion problems in two- and three-dimensional unbounded and semibounded solids for which explicit results can be obtained, without resort to approximate methods of integration. The mathematical techniques used, many of which appear here in book form for the first time, will be of interest to applied mathematicians, engeneers and scientists whose specialty includes crystal acoustics, crystal optics, magnetogasdynamics, dislocation theory, seismology and fibre wound composites. My interest in the subject of anisotropic wave motion had its origin in the study of small deformations superposed on large deformations of elastic solids. By varying the initial stretch in a homogeneously deformed solid, it is possible to synthesize aniso tropic materials whose elastic parameters vary continuously. The range of the parameter variation is limited by stability considerations in the case of small deformations super posed on large deformation problems and (what is essentially the same thing) by the of hyperbolicity (solids whose parameters allow wave motion) for anisotropic notion solids. The full implication of hyperbolicity for anisotropic elastic solids has never been previously examined, and even now the constraints which it imposes on the elasticity constants have only been examined for the class of transversely isotropic (hexagonal crystals) materials.




Ultrasound Elastography for Biomedical Applications and Medicine


Book Description

Ultrasound Elastography for Biomedical Applications and Medicine Ivan Z. Nenadic, Matthew W. Urban, James F. Greenleaf, Mayo Clinic Ultrasound Research Laboratory, Mayo Clinic College of Medicine, USA Jean-Luc Gennisson, Miguel Bernal, Mickael Tanter, Institut Langevin – Ondes et Images, ESPCI ParisTech CNRS, France Covers all major developments and techniques of Ultrasound Elastography and biomedical applications The field of ultrasound elastography has developed various techniques with the potential to diagnose and track the progression of diseases such as breast and thyroid cancer, liver and kidney fibrosis, congestive heart failure, and atherosclerosis. Having emerged in the last decade, ultrasound elastography is a medical imaging modality that can noninvasively measure and map the elastic and viscous properties of soft tissues. Ultrasound Elastography for Biomedical Applications and Medicine covers the basic physics of ultrasound wave propagation and the interaction of ultrasound with various media. The book introduces tissue elastography, covers the history of the field, details the various methods that have been developed by research groups across the world, and describes its novel applications, particularly in shear wave elastography. Key features: Covers all major developments and techniques of ultrasound elastography and biomedical applications. Contributions from the pioneers of the field secure the most complete coverage of ultrasound elastography available. The book is essential reading for researchers and engineers working in ultrasound and elastography, as well as biomedical engineering students and those working in the field of biomechanics.




Acoustic Interactions with Submerged Elastic Structures


Book Description

This series of volumes constitutes an outstanding collection of contributions by the most active research workers in the area of acoustics and mechanics. It brings the reader up to date on the status of the various aspects of research in this field. The volumes should preserve their value for a long time, as they represent a monument to the achievements of human research capabilities in the underwater-acoustics aspects of the environment.




Fractional Calculus And Waves In Linear Viscoelasticity: An Introduction To Mathematical Models (Second Edition)


Book Description

Fractional Calculus and Waves in Linear Viscoelasticity (Second Edition) is a self-contained treatment of the mathematical theory of linear (uni-axial) viscoelasticity (constitutive equation and waves) with particular regard to models based on fractional calculus. It serves as a general introduction to the above-mentioned areas of mathematical modeling. The explanations in the book are detailed enough to capture the interest of the curious reader, and complete enough to provide the necessary background material needed to delve further into the subject and explore the research literature. In particular the relevant role played by some special functions is pointed out along with their visualization through plots. Graphics are extensively used in the book and a large general bibliography is included at the end.This new edition keeps the structure of the first edition but each chapter has been revised and expanded, and new additions include a novel appendix on complete monotonic and Bernstein functions that are known to play a fundamental role in linear viscoelasticity.This book is suitable for engineers, graduate students and researchers interested in fractional calculus and continuum mechanics.




Wave Propagation in Viscoelastic and Poroelastic Continua


Book Description

Wave propagation is an important topic in engineering sciences, especially, in the field of solid mechanics. A description of wave propagation phenomena is given by Graff [98]: The effect of a sharply applied, localized disturbance in a medium soon transmits or 'spreads' to other parts of the medium. These effects are familiar to everyone, e.g., transmission of sound in air, the spreading of ripples on a pond of water, or the transmission of radio waves. From all wave types in nature, here, attention is focused only on waves in solids. Thus, solely mechanical disturbances in contrast to electro-magnetic or acoustic disturbances are considered. of waves - the compression wave similar to the In solids, there are two types pressure wave in fluids and, additionally, the shear wave. Due to continual reflec tions at boundaries and propagation of waves in bounded solids after some time a steady state is reached. Depending on the influence of the inertia terms, this state is governed by a static or dynamic equilibrium in frequency domain. However, if the rate of onset of the load is high compared to the time needed to reach this steady state, wave propagation phenomena have to be considered.




Review of Progress in Quantitative Nondestructive Evaluation


Book Description

These Proceedings, consisting of Parts A and B, contain the edited versions of most of the papers presented at the annual Review of Progress in Quantitative Nondestructive Evaluation held at Bowdoin College, Brunswick, Maine on July 28 to August 2, 1996. The Review was organized by the Center for NDE at Iowa State University, in cooperation with the American Society of Nondestructive Testing, the Ames Laboratory of the USDOE, the Federal Aviation Administration, the National Institute of Standardsand Technology, and the National Science Foundation Industry!University Cooperative Research Centers pro gram. This year's Review of Progress in QNDE was attended by approximately 400 participants from the U.S. and many foreign countries who presented over 350 papers. As usual, the meetingwas divided into 36 sessions, with as many as four sessions running concurrently. The Review covered all phases of NDE research and development from fundamental investigations to engineering applications or inspection systems, and it included many important methods of inspection techniques from acoustics to x-rays. In the last eight to ten years, the Review has stabilized at about its current size, which most participants seem to agree is large enough to permit a full-scale overview of the latest developments, but still small enough to retain the collegial atmosphere which has marked the Review since its inception.










Dynamics With Friction, Modeling, Analysis And Experiments, Part Ii


Book Description

The dynamics of dissipative mechanical and structural systems is being investigated at various institutions and laboratories worldwide with ever-increasing sophistication of modeling, analysis and experiments.This book offers a collection of contributions from these research centers that represent the state-of-the-art in the study of friction oscillators. It provides the reader with the fruits of a team effort by leaders in this fascinating field.The present part II of this volume on Dynamics with Friction is a continuation of the previous part I, and is designed to help synthesize our current knowledge regarding the role of friction in mechanical and structural systems as well as everyday life. The topics covered include interaction of vibration and friction at dry sliding contacts, friction-induced instability in disks, dynamics of lubricated flexible links in kinematic chains, modal interactions in periodic structures, dynamics of an experimentally excited beam, transient waves in viscoelastic materials, dynamic stability of plates with damping, friction modeling and dynamic computation, damping through use of passive and semi-active dry friction forces.This book gives a comprehensive picture of dynamics of dissipative mechanical and structural systems. It also gives an up-to-date account of the present state of the field. It will be of interest to engineers, rheologists, material scientists, applied mathematicians, physicists and historians of science and technology.