Srinivasan Gopalakrishnan – författare

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.

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.

The increased level of activity on structural health monitoring (SHM) in various universities and research labs has resulted in the development of new methodologies for both identifying the existing damage in structures and predicting the onset of damage that may occur during service. Designers often have to consult a variety of textbooks, journal papers and reports, because many of these methodologies require advanced knowledge of mechanics, dynamics, wave propagation, and material science. Computational Techniques for Structural Health Monitoring gives a one-volume, in-depth introduction to the different computational methodologies available for rapid detection of flaws in structures.Techniques, algorithms and results are presented in a way that allows their direct application. A number of case studies are included to highlight further the practical aspects of the selected topics.  Computational Techniques for Structural Health Monitoring also provides the reader with numerical simulation tools that are essential to the development of novel algorithms for the interpretation of experimental measurements, and for the identification of damage and its characterization.Upon reading Computational Techniques for Structural Health Monitoring, graduate students will be able to begin research-level work in the area of structural health monitoring. The level of detail in the description of formulation and implementation also allows engineers to apply the concepts directly in their research.

Pitting corrosion poses a significant threat to infrastructure in engineering and there is a lack of comprehensive modeling methodologies to assess the effectiveness of corrosion mitigation strategies specifically designed for various structural systems. This book addresses the need for comprehensive, advanced models that integrate the various stages and factors involved in the process. It covers corrosion fatigue mechanisms and the influence of stress and temperature, and ways to mitigate corrosion induced damage in structural components.Discusses exclusive material on modeling of the pitting corrosion processProvides a brief outline of experimental techniques for pitting corrosionAdvanced numerical modeling techniques are explained with a number of examplesPresents data on modular form for easy understanding of the modeling techniques Includes equations/flow charts to generate the numerical codesThis book is a reference for scholars, educators, and practitioners interested in exploring the potential of CPS for inclusive rural development.

The increased level of activity on structural health monitoring (SHM) in various universities and research labs has resulted in the development of new methodologies for both identifying the existing damage in structures and predicting the onset of damage that may occur during service. Designers often have to consult a variety of textbooks, journal papers and reports, because many of these methodologies require advanced knowledge of mechanics, dynamics, wave propagation, and material science. Computational Techniques for Structural Health Monitoring gives a one-volume, in-depth introduction to the different computational methodologies available for rapid detection of flaws in structures.Techniques, algorithms and results are presented in a way that allows their direct application. A number of case studies are included to highlight further the practical aspects of the selected topics.  Computational Techniques for Structural Health Monitoring also provides the reader with numerical simulation tools that are essential to the development of novel algorithms for the interpretation of experimental measurements, and for the identification of damage and its characterization.Upon reading Computational Techniques for Structural Health Monitoring, graduate students will be able to begin research-level work in the area of structural health monitoring. The level of detail in the description of formulation and implementation also allows engineers to apply the concepts directly in their research.

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 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.

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.

Wave Propagation in Nanostructures

Wave Propagation in Nanostructures describes the fundamental and advanced concepts of waves propagating in structures that have dimensions of the order of nanometers. The book is fundamentally based on non-local elasticity theory, which includes scale effects in the continuum model. The book predominantly addresses wave behavior in carbon nanotubes and Graphene structures, although the methods of analysis provided in this text are equally applicable to other nanostructures.The book takes the reader from the fundamentals of wave propagation in nanotubes to more advanced topics such as rotating nanotubes, coupled nanotubes, and nanotubes with magnetic field and surface effects. The first few chapters cover the basics of wave propagation, different modeling schemes for nanostructures and introduce non-local elasticity theories, which form the building blocks for understanding the material provided in later chapters. A number of interesting examples are provided to illustrate the important features of wave behavior in these low dimensional structures.

For centuries it has been the desire of human beings to ?nd better and better materials to achieve a variety of bene?ts for the mankind. This has been in vogue from the stone-age. The recent revolution discovering Smart Materials and Fu- tionally Graded Materials is one of those attempts. These materials are inherently multi functionaland theyopenedup possibilities whichcouldnot beimaginedinthe past. Materials can take a particulartype of energystimulusas input andgeneratean output belonging to a different type of energy. Typical example has been materials on which a mechanical force can produce electrical output. We are in twenty?rst century where in materials Research will totally concentrate on these new concepts and exploit them for variety of applications. Structural Health Monitoring leading to safety of operationsis the primary applicationthe aerospace, mechanical,nuclear and civil engineers will be expecting from this research. The Micro- and Na- scale sensors and actuators form the basis for this technology and Departments of Science and Technology in all the countries are investing heavily on this highly potential ?eld. InIndia,thescienti?cgroupinthisareaisactiveforthepastdecade.Theyformed in 1999 a professional society named as Institute of Smart Structures & Systems (ISSS) which has been holding National and International seminars and also he- ing the government departments to fund research and development of relevance to this novel materials and structures. National Program on Smart Materials (NPSM) and the second phase program NPMASS are the consequences of these efforts.

For centuries it has been the desire of human beings to ?nd better and better materials to achieve a variety of bene?ts for the mankind. This has been in vogue from the stone-age. The recent revolution discovering Smart Materials and Fu- tionally Graded Materials is one of those attempts. These materials are inherently multi functionaland theyopenedup possibilities whichcouldnot beimaginedinthe past. Materials can take a particulartype of energystimulusas input andgeneratean output belonging to a different type of energy. Typical example has been materials on which a mechanical force can produce electrical output. We are in twenty?rst century where in materials Research will totally concentrate on these new concepts and exploit them for variety of applications. Structural Health Monitoring leading to safety of operationsis the primary applicationthe aerospace, mechanical,nuclear and civil engineers will be expecting from this research. The Micro- and Na- scale sensors and actuators form the basis for this technology and Departments of Science and Technology in all the countries are investing heavily on this highly potential ?eld. InIndia,thescienti?cgroupinthisareaisactiveforthepastdecade.Theyformed in 1999 a professional society named as Institute of Smart Structures & Systems (ISSS) which has been holding National and International seminars and also he- ing the government departments to fund research and development of relevance to this novel materials and structures. National Program on Smart Materials (NPSM) and the second phase program NPMASS are the consequences of these efforts.

This book primarily focuses on methodologies to enable marine structures to resist high velocity impact loadings. It is based on invited talks presented at the recent India–USA workshop on “Recent Advances in Blast Mitigation Strategies in Civil and Marine Composite Structures” The book comprises content from top researchers from India and the USA  and covers various aspects of the topic, including modeling and simulation, design aspects, experimentation and various challenges. These failure modes significantly reduce the structural integrity of the marine structures unless they are designed to resist such harsh loadings. Understanding the mechanics of these structures under harsh loadings is still an open area of research, and the behavior of these structures is not fully understood. The book highlights efforts to reduce the effects of blast loadings on marine composite structures. Intended for researchers/scientists and practicing engineers, the book focuses not only the design and analysis challenges of marine composite structures under such harsh loading conditions, but also provides new design guidelines.

This book primarily focuses on methodologies to enable marine structures to resist high velocity impact loadings. Intended for researchers/scientists and practicing engineers, the book focuses not only the design and analysis challenges of marine composite structures under such harsh loading conditions, but also provides new design guidelines.

The book focuses primarily on experimental and analytical methods developed over many years to characterize the deformation and fracture of brittle materials under dynamic loading conditions. The dynamic response of brittle materials is highly nonlinear and complex, with practical applications ranging from explosive excavation of rocks to the design of ceramic armor and the protection of spacecraft windows from meteor impacts. It provides a comprehensive exploration of the challenges and methodologies involved in impact experiments and computational modeling of brittle solids under shock and impact loading, making it essential reading for those seeking realistic solutions to blast and ballistic problems.For example, the book emphasizes the significance of validating numerical code solutions through simulations. This involves understanding and evaluating the impact of various factors such as appropriate boundary conditions, high-resolution finite element meshes, solution time steps, contact algorithms, interface modeling, artificial viscosity, erosion of elements, particle conversion, and model parameters on the accuracy of solutions. It selectively presents examples of modeling and simulations of ballistic problems drawn from the open literature.While numerous articles on the book's topic exist in the literature, this volume integrates key aspects of high strain rate impact experiments, modeling, and simulations of brittle failure in ceramics, rocks, oil shale, and cementitious materials across various stress and strain states. To the best of the authors' knowledge, no other compilation covers such a wide array of experimental techniques used in this field, particularly for ceramics, yet adaptable for other heterogeneous brittle solids.Despite the extensive literature on this subject, most impact experimental configurations have been limited to specific geometries and have not encompassed the broad range of techniques necessary to characterize and validate constitutive behaviors used in modern numerical codes. Many researchers and engineers are often unaware of the specialized experiments and models presented in international conference proceedings or technical presentations. This book addresses that gap by encompassing a broader range of unique impact experiments, constitutive and damage modeling, and computational simulations not found in any existing publication.