Wave Propagation In Materials And Structures

This book focuses on basic and advanced concepts of wave propagation in diverse material systems and structures. Topics are organized in increasing order of complexity for better appreciation of the subject. Additionally, the book provides basic guidelines to design many of the futuristic materials and devices for varied applications. The material in the book also can be used for designing safer and more lightweight structures such as aircraft, bridges, and mechanical and structural components. The main objective of this book is to bring both the introductory and the advanced topics of wave propagation into one text. Such a text is necessary considering the multi-disciplinary nature of the subject. This book is written in a step-by step modular approach wherein the chapters are organized so that the complexity in the subject is slowly introduced with increasing chapter numbers. Text starts by introducing all the fundamental aspects of wave propagations and then moves on to advanced topics on the subject. Every chapter is provided with a number of numerical examples of increasing complexity to bring out the concepts clearly The solution of wave propagation is computationally very intensive and hence two different approaches, namely, the Finite Element method and the Spectral Finite method are introduced and have a strong focus on wave propagation. The book is supplemented by an exhaustive list of references at the end of the book for the benefit of readers.

Wave propagation is any of the ways in which waves travel. With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves. For electromagnetic waves, propagation may occur in a vacuum as well as in a material medium. Other wave types cannot propagate through a vacuum and need a transmission medium to exist. In the recent decades, there has been a growing interest in micro- and nanotechnology. The advances in nanotechnology give rise to new applications and new types of materials with unique electromagnetic and mechanical properties. Wave Propagation in Materials and Structures is devoted to the modern methods developed to describe wave propagation in modern materials and structures. The book contains original works of prominent scientists in the field of wave propagation who produced new theoretical and experimental methods in the research field and obtained new and important results. Elastic wave propagation has been used for years for assessment of the structural integrity of engineering materials. The advantage it deals is the direct association to elastic properties, the quite easy application through commercial equipment along with numerous empirical correlations between pulse velocity and material strength or quality in general. Advanced features like frequency dependence of wave parameters may further improve the characterisation capacity. Concrete materials because of their intrinsic microstructure, which is enhanced by the existence of damage-induced cracking, demonstrate a complicated behavior relating to the propagation of pulses of different frequencies. The different wave lengths interact with inhomogeneities according to their size and therefore, leave their signature on the phase velocity and attenuation versus frequency curves. Although experimental measurements are troublesome in concrete structures, mainly due to attenuation of high frequencies, it is suggested that, whenever possible, application of different frequencies can provide a more detailed insight on the internal condition of the structure. This book intends to basic and advanced concepts of wave propagation in diverse material systems and structures. Such a text is necessary considering the multi-disciplinary nature of the subject. Therefore, actively working readers (scientists, engineers, students, as well as researchers and practitioners) will find many interesting results and new ideas in this book.

Elastic Wave Propagation in Structures and Materials initiates with a brief introduction to wave propagation, different wave equations, integral transforms including fundamentals of Fourier Transform, Wavelet Transform, Laplace Transform and their numerical implementation. Concept of spectral analysis and procedure to compute the wave parameters, wave propagation in 1-D isotropic waveguides, wave dispersion in 2-D waveguides is explained. Wave propagation in different media such as laminated composites, functionally graded structures, granular soils including non-local elasticity models is addressed. The entire book is written in modular form and analysis is performed in frequency domain. Features: Brings out idea of wave dispersion and its utility in the dynamic responses. Introduces concepts as Negative Group Speeds, Einstein’s Causality and escape frequencies using solid mathematical framework. Discusses the propagation of waves in materials such as laminated composites and functionally graded materials. Proposes spectral finite element as analysis tool for wave propagation. Each concept/chapter supported by homework problems and MATLAB/FORTRAN codes. This book aims at Senior Undergraduates and Advanced Graduates in all streams of engineering especially Mechanical and Aerospace Engineering.

This book focuses on basic and advanced concepts of wave propagation in diverse material systems and structures. Topics are organized in increasing order of complexity for better appreciation of the subject. Additionally, the book provides basic guidelines to design many of the futuristic materials and devices for varied applications. The material in the book also can be used for designing safer and more lightweight structures such as aircraft, bridges, and mechanical and structural components. The main objective of this book is to bring both the introductory and the advanced topics of wave propagation into one text. Such a text is necessary considering the multi-disciplinary nature of the subject. This book is written in a step-by step modular approach wherein the chapters are organized so that the complexity in the subject is slowly introduced with increasing chapter numbers. Text starts by introducing all the fundamental aspects of wave propagations and then moves on to advanced topics on the subject. Every chapter is provided with a number of numerical examples of increasing complexity to bring out the concepts clearly The solution of wave propagation is computationally very intensive and hence two different approaches, namely, the Finite Element method and the Spectral Finite method are introduced and have a strong focus on wave propagation. The book is supplemented by an exhaustive list of references at the end of the book for the benefit of readers.

Elastic Wave Propagation in Structures and Materials initiates with a brief introduction to wave propagation, different wave equations, integral transforms including fundamentals of Fourier Transform, Wavelet Transform, Laplace Transform and their numerical implementation. Concept of spectral analysis and procedure to compute the wave parameters, wave propagation in 1-D isotropic waveguides, wave dispersion in 2-D waveguides is explained. Wave propagation in different media such as laminated composites, functionally graded structures, granular soils including non-local elasticity models is addressed. The entire book is written in modular form and analysis is performed in frequency domain. Features: Brings out idea of wave dispersion and its utility in the dynamic responses. Introduces concepts as Negative Group Speeds, Einstein’s Causality and escape frequencies using solid mathematical framework. Discusses the propagation of waves in materials such as laminated composites and functionally graded materials. Proposes spectral finite element as analysis tool for wave propagation. Each concept/chapter supported by homework problems and MATLAB/FORTRAN codes. This book aims at Senior Undergraduates and Advanced Graduates in all streams of engineering especially Mechanical and Aerospace Engineering.

This book is the first to apply the Spectral Finite Element Method (SFEM) to inhomogeneous and anisotropic structures in a unified and systematic manner. Readers will gain understanding of how to formulate Spectral Finite Element; learn about wave behaviour in inhomogeneous and anisotropic media; and, be able to design some diagnostic tools for monitoring the health of a structure. Tables, figures and graphs support the theory and case studies are included.

This book introduces spectral analysis as a means of investigating wave propagation and transient oscillations in structures. After developing the foundations of spectral analysis and the fast Fourier transform algorithm, the book provides a thorough treatment of waves in rods, beams, and plates, and introduces a novel matrix method for analysing complex structures as a collection of waveguides. The presentation includes an introduction to higher-order structural theories, the results of many experimental studies, practical applications, and source-code listings for many programs. An extensive bibliography provides an entry to the research literature. Intended as a textbook for graduate students of aerospace or mechanical engineering, the book will also be of interest to practising engineers in these and related disciplines.