Author: A. Alippi
Publisher: Springer Science & Business Media
ISBN: 9400935757
Category : Technology & Engineering
Languages : en
Pages : 407
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Book Description
The purpose of the School, the content of which is reflected in this book, is to bring together experiences and knowledge of those acousticians who are particularly sensible to materials and their properties, specifically to those materials that may be called inhomo geneous. The two things together: acoustics and inhomogeneity, define factually a dimension less parameter, AI a, which is the ratio between the sound wavelength and the spatial length of the material where its physical characteristics notably change. An implicit defmition is, therefore, at hand for an inhomogeneous medium, which has the characteristic of a condi tioned definition and sets a looser constraint to the otherwise strict statement of invariance under translations. Composite, biologicai, porous, stratified materials are in the list of inhomogeneous materials, whose technological or structural interest has grown greatly in recent times. Ul trasonic waves offer a means for their investigation, which is valuable for it can be non destructive, continuous in time, spatially localized, dependent on the size of inhomoge neities.
Author: Chinta, Prashanth Kumar
Publisher: kassel university press GmbH
ISBN: 386219616X
Category : Ultrasonic testing
Languages : en
Pages : 173
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Book Description
This thesis discusses ultrasonic testing by means of numerical modeling and image reconstruction techniques using elastic and acoustic wave fields. Numerical modeling of elastic waves (part one of the thesis) is used to understand the elastic wave scattering due to material defects and the propagation of surface waves in inhomogeneous isotropic and anisotropic media, with special emphasis on transversely isotropic and orthotropic media. Different imaging techniques (part two of the thesis) are investigated to develop a software, implemented in Matlab, which can give imaging results immediately after the measurement almost in real time as it can read and process the data obtained directly from the measurement. Acoustic wave scattering using analytical techniques and imaging techniques based on Radon transform are investigated. The data obtained from the Radon transform are subjected for imaging utilizing the filtered back projection algorithm and the Fourier slice theorem. The fundamentals of elastic wave propagation in solids are extensively elaborated. The point source synthesis to compute the Green’s functions for anisotropic media and the plane wave synthesis to compute slowness, phase and group velocity surfaces are studied. The elastic integral equations for the so called stretched coordinate system are derived. Based on these equations the numerical tool ’Three-dimensional Elastodynamic Finite Integration Technique’ (3D-EFIT) has been enhanced to treat not only isotropic media but also anisotropic media. For fast computation, the 3D-EFIT code using the Message Passing Interface (MPI) is used by which processing on massive parallel computers is made possible. In 3D-EFIT the Convolutional Perfectly Matched Layers (CPML) can also be applied to absorb the elastic body waves as well as the surface and evanescent waves. 3D-EFIT for homogeneous anisotropic media is validated by comparing computed Green’s functions with an analytical solution. After the validation, the applications of EFIT such as elastic wave modeling in inhomogeneous austenitic steel welds and inhomogeneous orthotropic wooden structures are presented. The results of the 2D-EFIT and 3D-EFIT modeling are compared against measurements performed at Federal Institute for Materials Research and Testing (BAM). After the modeling part of the thesis, inverse scattering techniques for fast imaging of inhomogeneities are studied. For three-dimensional imaging of defects in concrete, the Synthetic Aperture and Focusing Technique (SAFT) and Fourier Transformed Synthetic aperture Focusing Technique (FT-SAFT) are applied to data measured using a transducer array. The seismic Dip-Moveout (DMO) method has been utilized to convert measured bistatic data into monostatic data. A special treatment of SAFT as a technique for back propagation of the wave fields using time reversal, utilizing the knowledge of the geometry, is presented. Finally, time domain anisotropic SAFT (AnSAFT) is studied for image reconstruction of defects in inhomogeneous geometry with orthotropic crystal structure of the embedding medium.
Author: Chi-hau Chen
Publisher: World Scientific
ISBN: 9812704094
Category : Medical
Languages : en
Pages : 682
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Book Description
Ultrasonic methods have been very popular in nondestructive testing and characterization of materials. This book deals with both industrial ultrasound and medical ultrasound. The advantages of ultrasound include flexibility, low cost, in-line operation, and providing data in both signal and image formats for further analysis. The book devotes 11 chapters to ultrasonic methods. However, ultrasonic methods can be much less effective with some applications. So the book also has 14 chapters catering to other or advanced methods for nondestructive testing or material characterization. Topics like structural health monitoring, Terahertz methods, X-ray and thermography methods are presented. Besides different sensors for nondestructive testing, the book places much emphasis on signal/image processing and pattern recognition of the signals acquired.
Author: Karl-Jörg Langenberg
Publisher: CRC Press
ISBN: 1439855900
Category : Science
Languages : en
Pages : 756
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Book Description
This book features a comprehensive discussion of the mathematical foundations of ultrasonic nondestructive testing of materials. The authors include a brief description of the theory of acoustic and electromagnetic fields to underline the similarities and differences with respect to elastodynamics. They also cover vector, elastic plane, and Rayleigh surface waves as well as ultrasonic beams, inverse scattering, and ultrasonic nondestructive imaging. A coordinate-free notation system is used that is easier to understand and navigate than standard index notation.
Author: Tribikram Kundu
Publisher: CRC Press
ISBN: 9780203501962
Category : Science
Languages : en
Pages : 848
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Book Description
Most books on ultrasonic nondestructive evaluation (NDE) focus either on its theoretical background or on advanced applications. Furthermore, information on the most current applications, such as guided wave techniques and acoustic microscopy, is scattered throughout various conference proceedings and journals. No one book has integrated these aspe
Author: J.D. Achenbach
Publisher: Springer
ISBN: 3709143152
Category : Technology & Engineering
Languages : en
Pages : 392
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Book Description
Nondestructive evaluation (NDE) procedures are needed for materials processing, as well as for post-process materials testing. They play important roles in product design, analysis of service-life expectancy, manufacturing and quality control of manufactured products. They are also essential to on-line monitoring of the integrity of structural elements and complex systems. Rational accept and reject criteria should be based on NDE tests. Critical safety, efficiency and operational features of large-scale structures depend on adequate NDE capabilities. The lectures presented in this volume are concerned with quantitative ultrasonic NDE. They present fundamental concepts and basic theory, as well as applications to the detection of cracks and the evaluation of material properties. The following topics are discussed: basic wave propagation theory for ultrasonic NDE; piezoelectric transducers, EMATS and ultrasonic spectroscopy; laser-based ultrasonics; acoustoelasticity; ultrasound in solids with porosity, microcracking and polycrystalline structuring; the determination of mechanical properties of composite materials; inverse problems and imaging.
Author: Karl-Jörg Langenberg
Publisher: CRC Press
ISBN: 1439855889
Category : Science
Languages : en
Pages : 774
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Book Description
Ultrasonic Nondestructive Testing of Materials: Theoretical Foundations explores the mathematical foundations and emerging applications of this testing process, which is based on elastic wave propagation in isotropic and anisotropic solids. In covering ultrasonic nondestructive testing methods, the book emphasizes the engineering point of view, yet it relies on the physics and mathematics aspects involved in elastic wave propagation theory. As a result, this resource becomes a missing link in the literature by combining coverage of the theoretical aspects of testing and providing intuitive assessments of numerous standard problems to illustrate fundamental assertions. Content includes a brief description of the theory of acoustic and electromagnetic fields to underline the similarities and differences as compared to elastodynamics. It also covers vector algebra and analysis, elastic plane and Rayleigh surface waves, and ultrasonic beams, as well as transducer radiation, inverse scattering, and ultrasonic nondestructive imaging. Includes numerical computations to explain wave propagation phenomena and compare results of analytical formulations Although ultrasonic nondestructive testing can often be roughly understood in terms of plane waves and beams, this book addresses the key issues of transducer radiation and defect scattering and imaging, respectively. The authors physically formulate point source synthesis, and, in mathematical terms, they use representation integrals with Green functions, always including intuitive interpretations with mathematical evaluations. Replacing cumbersome index notation with a coordinate-free version, this reference offers step-by-step documentation of relevant tensorial elastodynamic cases involving isotropic and anisotropic materials. It provides all necessary mathematical tools readers require to understand the mathematical and physical basis for ultrasonic nondestructive testing.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Resonant Ultrasound Spectroscopy (RUS) has been used successfully to determine the elastic properties of single crystal and homogeneous materials. We have attempted to answer the following question. Under what conditions is RUS a useful tool for determining the moduli of macroscopic, inhomogeneous samples. We concentrated on identifying a sample geometry that will maximize success with RUS. The work consisted of numerical modeling of sample resonances under varying conditions, and empirical testing of rock samples. Numerical modeling and empirical testing indicate that RUS is a viable technique for characterizing the average isotropic elastic moduli of inhomogeneous materials, although larger RMS errors can be expected than for single crystal materials. Success with RUS can optimized by ensuring that the sample size is large compared to the scale of inhomogeneity and by using a high aspect ratio parallelepiped sample.
Author: K. Kirk Shung
Publisher: CRC Press
ISBN: 1351406361
Category : Medical
Languages : en
Pages : 520
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Book Description
Ultrasonic Scattering in Biological Tissues contains 14 chapters written by world-renowned authorities who describe current work related to theoretical and experimental aspects of ultrasonic scattering phenomenon in biological tissues. Introductory material regarding ultrasonic scattering in biological tissues is presented, followed by discussions on theoretical treatments, experimental approaches, in vitro results on selective tissues, in vivo results on various tissues, and the current status of quantitative backscatter imaging. Ultrasonic Scattering in Biological Tissues will be an excellent reference for biomedical engineers, ultrasound specialists, biophysicists, and radiology researchers.
Author: Lester W. Schmerr Jr
Publisher: Springer Science & Business Media
ISBN: 0387490639
Category : Technology & Engineering
Languages : en
Pages : 602
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Book Description
Using a systems level approach, this book employs aspects of linear systems theory and wave propagation and scattering theory to develop a comprehensive model of an entire ultrasonic measurement system. This integrated approach leads to a new model-based engineering technology for designing, using and optimizing ultrasonic nondestructive evaluation inspections. In addition, the book incorporates MATLAB examples and exercises.
