Physical Ultrasonics Of Composites

The objective of this book is to treat the behavior of ultrasonic waves as they interact with layered, anisotropic materials incorporating those structural aspects unique to composite laminates addressing both experimental and modeling methodologies. Anisotropic material interfaces, guided waves, waves in layered media and laminated plates are treated. The influence of finite-aperture transducers on electronic signals and the field of air-coupled ultrasonics end the work.

Ultrasonic waves provide an excellent means to study the mechanical properties of both heterogeneous and composite materials. Recently, both theoretically and experimentally, we studied characteristics of elastic wave propagation through fiber and particle reinforced composites. Theoretically we analyzed phase velocities of longitudinal and shear waves propagating through composite media with aligned continuous fibers and ellipsoidal shaped particles. Alignment of reinforcing fibers (or particles) imparts anisotropy to the effective mechanical and physical properties of the composite. Theoretically, we modeled the anisotropic phase velocities, which agree with experimental measurements. One important feature of this combined theoretical and experimental study is the possibility of obtaining the (often uncertain) fiber (or particle) elastic properties by comparing the model predictions with the observations. We show that one can use the theoretical model to obtain effective properties of media containing voids (Pores). As examples, we consider porous olivine and creep cavities in copper. In the latter case some experimental results are presented which show good agreement with predictions. Finally, we present some results for attenuation in a particulate composite including the effect of nonideal interface properties. (Author).

This book deals with all aspects of advanced composite materials; what they are, where they are used, how they are made, their properties, how they are designed and analyzed, and how they perform in-service. It covers both continuous and discontinuous fiber composites fabricated from polymer, metal, and ceramic matrices, with an emphasis on continuous fiber polymer matrix composites.

This book contains 17 invited papers and 80 communicated papers presented at the International Symposium on Physical Acoustics, held at the University Campus of Kortrijk, Belgium, from 19-22 June 1990. The twenty-fifth anniversary of the Campus was celebrated with special activi ties such as concerts, exhibitions and scientific meetings. This symposium was a part of the celebration. The 120 participants came from 18 different countries. Among the largest groups we mention 32 French contributions and 19 contributions from the U.S.S.R. We especially thank Prof. V.V. Proklov from Moscow and Prof. S.V. Kulakov from Leningrad who helped us with the distribution of invitations in the U.S.S.R. We also thank Prof. G. Quentin and Ir B. Poiree from Paris who endeav oured to inform all French acousticians. We thank all the lecturers for their effort in producing the material for the book in time. The invited lectures have been collected and retyped by Prof. M. Breazeale (U.S.A.), while the contributed papers were collec ted by Prof. O. Leroy and retyped in Belgium. The first 200 pages of the book comprise the invited lectures, not classified by topic, but are in alphabetical order with reference to the first author. The second part of the book contains the contributed papers and posters also classified in alphabetical order according to the first author.

The increased use of polymer matrix composites in structural applications has led to the growing need for a very high level of quality control and testing of products to ensure and monitor performance over time. Non-destructive evaluation (NDE) of polymer matrix composites explores a range of NDE techniques and the use of these techniques in a variety of application areas. Part one provides an overview of a range of NDE and NDT techniques including eddy current testing, shearography, ultrasonics, acoustic emission, and dielectrics. Part two highlights the use of NDE techniques for adhesively bonded applications. Part three focuses on NDE techniques for aerospace applications including the evaluation of aerospace composites for impact damage and flaw characterisation. Finally, the use of traditional and emerging NDE techniques in civil and marine applications is explored in part four. With its distinguished editor and international team of expert contributors, Non-destructive evaluation (NDE) of polymer matrix composites is a technical resource for researchers and engineers using polymer matrix composites, professionals requiring an understanding of non-destructive evaluation techniques, and academics interested in this field. Explores a range of NDE and NDT techniques and considers future trends Examines in detail NDE techniques for adhesively bonded applications Discusses NDE techniques in aerospace applications including detecting impact damage, ultrasonic techniques and structural health monitoring

A model is developed relating composite constituents properties with ultrasonic energy loss factors for longitudinal waves propagating in the principal directions of a unidirectional graphite/epoxy fiber composite. All the constituents are assumed to behave as linear viscoelastic materials with energy dissipation properties defined by loss factors. It is found that by introducing a new constituent called the interface material, the composite and constituent properties can be brought into consistency with simple series and parallel models. An expression relating the composite loss factors to the loss factors of the constituents is derived and its coefficients are evaluated. Williams, J. H., Jr. and Lee, S. S. and Nayebhashemi, H. Unspecified Center NASA-CR-3181 NSG-3210

New applications for composite materials are being developed at a rapid pace. However, their complex microstructures present considerable challenges for nondestructive testing and characterization. Ultrasonic waves provide quantitative means of nondestructive evaluation of these materials and structures. For this purpose, it is necessary to obtain

Non Destructive Testing and Non Destructive Evaluation using Ultrasounds covers an important field of applications and requires a wide range of fundamental theoretical, numerical and experimental investigations. In the present volume, the reader will find some relevant research results on wave propagation in complex materials and structures which are concerned with today’s problems on composites, bonding, guided waves, contact or damage, imaging and structural noise. The fifth meeting of the Anglo-French Research Group on "Wave propagation in non homogeneous media with a view to Non Destructive testing" was held in Anglet, France, June 2-6, 2008.