Spectral Finite Element Method: Wave Propagation, Diagnostics and Control in Anisotropic and Inhomogeneous Structures

ISBN-13: 9781846283550 / Angielski / Twarda / 2007 / 440 str.

Gopalakrishnan Srinivasan; Debiprosad Roy Mahapatra; Abir Chakraborty

Opis

Wave propagation is an exciting ?eld having applications cutting across many disciplines. In the ?eld of structural engineering and smart structures, wave propagation based tools have found increasing applications especially in the areaofstructuralhealthmonitoringandactivecontrolofvibrationsandnoise. Inaddition, therehasbeentremendousprogressintheareaofmaterialscience, wherein a new class of structural materials is designed to meet the parti- lar application. In most cases, these materials are not isotropic as in metallic structures. They are either anisotropic (as in the case of laminated composite structures) or inhomogeneous (as in the case of functionally graded mate- als). Analysis of these structures is many orders more complex than that of isotropic structures. For many scientists/engineers, a clear di?erence between structural dynamics and wave propagation is not evident. Traditionally, a structural designer will not be interested in the behavior of structures beyond certain frequencies, which are essentially at the lower end of the frequency scale. For such situations, available general purpose ?nite element code will satisfy the designer s requirement. However, currently, structures are required tobedesignedtosustainverycomplexandharshloadingenvironments. These loadings are essentially multi-modal phenomena and their analysis falls under the domain of wave propagation rather than structural dynamics. Evaluation of the structural integrity of anisotropic and inhomogeneous structures s- jected to such loadings is a complex process. The currently available analysis tools are highly inadequate to handle the modeling of these structures. In this book, we present a technique called the Spectral Finite Element Method, whichwebelievewilladdresssomeoftheshortcomingsoftheexistinganalysis tools."

Recenzje

From the reviews:

"The book deals with wave propagation and related problems of identification and control for anisotropic composites with particular emphasis on laminated and graded structures. It is intended for graduate and senior undergraduate students and researchers in engineering disciplines. … The book presents some interesting results in material sciences. The researchers in this area will find it useful in a number of applications." (Fiazud Din Zaman, Zentralblatt MATH, Vol. 1145, 2008)

Spis treści

Introduction Introduction to theory of anisotropic and inhomogenous materials Idealization of wave propagation and solution techniques Wave propagation in one-dimensional anisotropic structures Wave propagation in one-dimensional inhomogenous structures Wave propagation in two-dimensional anisotropic structures Wave propagation in two-dimensional inhomogenous structures Solution of inverse problems: source and system identification Application of SFEM to SHM: simplified damage models Application of SFEM to SHM: efficient damage detection techniques Spectral finite element mehod for active wave control

O autorze

Prof. S. Gopalakrishnan is an Associate Professor at the Indian Institute of Science, Bangalore, India. He has a decade of experience in applying wave based techniques for solving various structural engineering related problems. He is internationally recognized as one of the experts in the field, and is one of the few people responsible for popularizing the use of SFEM through his research publications and presentations.

Dr A. Chakraborty is a Senior Researcher at General Motors India.

Dr Roy Mahapatra is an Assistant Professor at the Indian Institute of Science, Bangalore, India. His research activities are related to the mechanics and dynamics of solid-state engineering materials and structures, and the study of complex systems.

Blurb

In recent times, the use of composites and functionally graded materials (FGMs) in structural applications has increased. FGMs allow the user to design materials for a specified functionality and therefore have numerous uses in structural engineering. However, the behavior of these structures under high-impact loading is not well understood. Spectral Finite Element Method: Wave Propagation, Diagnostics and Control in Anisotropic and Inhomogeneous Structures focuses on some of the wave propagation and transient dynamics problems with these complex media which had previously been thought unmanageable.

By using state-of-the-art computational power, the Spectral Finite Element Method (SFEM) can solve many practical engineering problems. This book is the first to apply SFEM to inhomogeneous and anisotropic structures in a unified and systematic manner. The authors discuss the different types of SFEM for regular and damaged 1-D and 2-D waveguides, various solution techniques, different methods of detecting the presence of damages and their locations, and different methods available to actively control the wave propagation responses. The theory is supported by tables, figures and graphs; all the numerical examples are designed to bring out the essential wave behavior in these complex structures. Some case studies based on real-world problems are also presented.

This book is intended for senior undergraduate students and graduate students studying wave propagation in structures, smart structures, spectral finite element method and structural health monitoring. Readers will gain a complete understanding of how to formulate a spectral finite element; learn about wave behavior in inhomogeneous and anisotropic media; and, discover how to design some diagnostic tools for monitoring the health or integrity of a structure. The book will also be of value to researchers and practicing engineers in structural integrity.