Elastic characterization of anisotropic materials by speckle interferometry

Physical Ultrasonics of Composites is a rigorous introduction to the characterization of composite materials by means of ultrasonic waves. Composites are treated here not simply as uniform media, but as inhomogeneous layered anisotropic media with internal structure characteristic of composite laminates. The objective here is to concentrate on exposing the singular behavior of ultrasonic waves as they interact with layered, anisotropic materials, materials which incorporate those structural elements typical of composite laminates. This book provides a synergistic description of both modeling and experimental methods in addressing wave propagation phenomena and composite property measurements. After a brief review of basic composite mechanics, a thorough treatment of ultrasonics in anisotropic media is presented, along with composite characterization methods. The interaction of ultrasonic waves at interfaces of anisotropic materials is discussed, as are guided waves in composite plates and rods. Waves in layered media are developed from the standpoint of the "Stiffness Matrix", a major advance over the conventional, potentially unstable Transfer Matrix approach. Laminated plates are treated both with the stiffness matrix and using Floquet analysis. The important influence on the received electronic signals in ultrasonic materials characterization from transducer geometry and placement are carefully exposed in a dedicated chapter. Ultrasonic wave interactions are especially susceptible to such influences because ultrasonic transducers are seldom more than a dozen or so wavelengths in diameter. The book ends with a chapter devoted to the emerging field of air-coupled ultrasonics. This new technology has come of age with the development of purpose-built transducers and electronics and is finding ever wider applications, particularly in the characterization of composite laminates.

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Characterization of microvibrations by speckle interferometry

10.1117/12.212646 ◽

1995 ◽

Cited By ~ 2

Author(s):

Roland Hoefling ◽

Volkmar Liebig ◽

Claus-Dieter Schmidt

Keyword(s):

Speckle Interferometry

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Mathematical methods for the characterization of ultrasound in anisotropic materials

Canadian Journal of Physics ◽

10.1139/p00-054 ◽

2000 ◽

Vol 78 (9) ◽

pp. 803-821 ◽

Cited By ~ 3

Author(s):

B O'Neill ◽

R Gr. Maev

Keyword(s):

Wave Propagation ◽

Acoustic Waves ◽

Asymptotic Theory ◽

Anisotropic Materials ◽

Bulk Wave ◽

Mathematical Methods ◽

Theoretical Methods ◽

The Past ◽

Fundamental Equations

Although the fundamental equations for the propagation of elastic and acoustic waves in anisotropic materials have not changed in more than a 100 years, the last few decades have seen a surge in interest in the topic. Much of this interest stems from the growing need for characterization of an increasing number of exotic materials. The intent of this paper is to review, for the benefit of beginning researchers in acoustics and ultrasonics, the fundamental phenomena related to elastic wave propagation in anisotropic media. We also present the most common and interesting theoretical methods developed over the past 20 years to model bulk wave propagation in such media. The methods discussed include plane wave superpositions, ray asymptotic theory, paraxial beams, and Green's functions. More peripheral issues, including anisotropic effects combined with various other exotic effects, are dealt with in the bibliography. PACS No.: 43.90

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Rheological characterization of anisotropic materials

Composites ◽

10.1016/0010-4361(89)90677-0 ◽

1989 ◽

Vol 20 (1) ◽

pp. 21-27 ◽

Cited By ~ 105

Author(s):

T.G. Rogers

Keyword(s):

Anisotropic Materials ◽

Rheological Characterization

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Microdamage in Composite Laminates: Experiments and Observation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.518.84 ◽

2014 ◽

Vol 518 ◽

pp. 84-89

Author(s):

Janis Varna ◽

Leif Asp

Keyword(s):

Composite Laminates ◽

Speckle Interferometry ◽

Damage State ◽

Axis Orientation ◽

Fiber Reinforced Composite ◽

X Ray ◽

Reinforced Composite ◽

Loading Direction ◽

Intralaminar Cracking

The first mode of damage in fiber reinforced composite laminates is usually intralaminar cracking in layers with off-axis orientation regarding the main loading direction. This papers analyzes the most typical methods used for the characterization of the damage state: edge replicas, optical microscopy, x-ray images, acoustic emission, speckle interferometry and Raman spectroscopy

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