Integration of theoretical developments offers complete description of linear theory of viscoelastic behavior of materials, with theoretical formulations derived from continuum mechanics viewpoint and discussions of problem solving. 1982 ...

Author: R. M. Christensen

Publisher: Courier Corporation

ISBN: 9780486318967

Category: Technology & Engineering

Page: 384

View: 261

Integration of theoretical developments offers complete description of linear theory of viscoelastic behavior of materials, with theoretical formulations derived from continuum mechanics viewpoint and discussions of problem solving. 1982 edition.

Richard Allan Schapery. REFERENCES . 1 . Biot , M . A . : " Theory of Stress -
Strain Relations in Anisotropic Viscoelasticity and Relaxation Phenomena , "
Journal of Applied Physics , ( 1954 ) 25 pp . 1385 - 91 . 3 . Biotsolido , pero Biot ,
M . A ...

Author: Richard Allan Schapery

Publisher:

ISBN: CORNELL:31924004125468

Category: Irreversible processes

Page: 348

View: 445

A unified theory of the thermo-mechanical behavior of viscoelastic media is developed from studying the thermodynamics of irreversible processes, and includes discussions of the general equations of motion, crack propagation, variational principles, and approximate methods of stress analysis.

The book: presents a development of the theory, addressing both transient and dynamic aspects as well as emphasizing linear viscoelasticity synthesizes the structure of the theory with the aim of developing physical insight illustrates the ...

Author: Roderic S. Lakes

Publisher: CRC Press

ISBN: 9781351355650

Category: Technology & Engineering

Page: 490

View: 127

Viscoelastic Solids covers the mathematical theory of viscoelasticity and physical insights, causal mechanisms, and practical applications. The book: presents a development of the theory, addressing both transient and dynamic aspects as well as emphasizing linear viscoelasticity synthesizes the structure of the theory with the aim of developing physical insight illustrates the methods for the solution of stress analysis problems in viscoelastic objects explores experimental methods for the characterization of viscoelastic materials describes the phenomenology of viscoelasticity in a variety of materials, including polymers, metals, high damping alloys, rock, piezoelectric materials, cellular solids, dense composite materials, and biological materials analyzes high damping and extremely low damping provides the theory of viscoelastic composite materials, including examples of various types of structure and the relationships between structure and mechanical properties contains examples on the use of viscoelastic materials in preventing and alleviating human suffering Viscoelastic Solids also demonstrates the use of viscoelasticity for diverse applications, such as earplugs, gaskets, computer disks, satellite stability, medical diagnosis, injury prevention, vibration abatement, tire performance, sports, spacecraft explosions, and music.

Using a newly developed three dimensional, time dependent finite volume code designed to compute non-Newtonian flows over a large range of Reynolds number (Re), we performed simulations of viscoelastic flow past a circular cylinder.

Author:

Publisher: Stanford University

ISBN: STANFORD:rt906yk9790

Category:

Page:

View: 319

Using a newly developed three dimensional, time dependent finite volume code designed to compute non-Newtonian flows over a large range of Reynolds number (Re), we performed simulations of viscoelastic flow past a circular cylinder. Our goal was to elucidate elastic effects during transition to turbulence in a bluff body wake. Based on its ability to capture essential physical processes in turbulent drag reduction studies, the FENE-P rheological model was employed in the calculation, and the numerical method utilized was such that a large range of rheological parameters (polymer length L, dimensionless Weissenberg number (Wi), and polymer concentration (beta) in the FENE-P model) could be probed. Simulations were performed for Reynolds numbers ranging from Re = 100 to Re = 3900. Within this range, the Newtonian cylinder wake first undergoes a series of secondary instabilities, transitioning the wake structure from a two-dimensional, laminar vortex shedding state to one exhibiting three-dimensional motion. This transition is characterized first by the mode A instability, which develops in the region of primary vortex development at a Reynolds number of Re = 190. The mode B instability then follows at Re = 260, resulting from unstable perturbation growth in the braid region between primary vortices. At still higher Reynolds numbers, Re = O(1000), the separated shear layer immediately behind the cylinder begins to transition prior to primary vortex shedding. Through nonlinear simulations as well as a Floquet linear stability analysis, viscoelasticity was observed to stabilize both regimes of three-dimensional transition. Full nonlinear simulations revealed that for high enough polymer extensibility L at Re = 300, where mode B instability structures dominate for Newtonian flow, the wake could be reverted back to a state resembling two-dimensional, laminar vortex shedding. This was then confirmed using a Floquet stability analysis, showing significantly suppressed growth rates for both the mode A and mode B instabilities in the linear regime of their development. Mechanisms of this stabilization are presented. At Re = 3900, viscoelasticity again stabilizes the flow, though at this point through a suppression of the Kelvin-Helmoltz rollup instability present in the separated shear layer for Newtonian flows. Once a primary Karman vortex is allowed to form without the influence of a transitioned shear layer, the wake then reverts back to one resembling the mode B instabilities. Confirming this, a study was then performed at the same Reynolds number but allowing for an inhomogeneous polymer concentration throughout the flow field. By injecting polymer additives on the upstream side of the cylinder, it was found that stabilization of the shear layer and of the subsequent wake could be achieved without the presence of polymeric stresses in all downstream locations of the flow.

This graduate text on viscoelastic materials addresses design applications as diverse as earplugs, computer disks and medical diagnostics.

Author: Roderic S. Lakes

Publisher: Cambridge University Press

ISBN: 9780521885683

Category: Science

Page: 461

View: 965

Understanding viscoelasticity is pertinent to design applications as diverse as earplugs, gaskets, computer disks, satellite stability, medical diagnosis, injury prevention, vibration abatement, tire performance, sports, spacecraft explosions, and music. This book fits a one-semester graduate course on the properties, analysis, and uses of viscoelastic materials. Those familiar with the author's precursor book, Viscoelastic Solids, will see that this book contains many updates and expanded coverage of the materials science, causes of viscoelastic behavior, properties of materials of biological origin, and applications of viscoelastic materials. The theoretical presentation includes both transient and dynamic aspects, with emphasis on linear viscoelasticity to develop physical insight. Methods for the solution of stress analysis problems are developed and illustrated. Experimental methods for characterization of viscoelastic materials are explored in detail. Viscoelastic phenomena are described for a wide variety of materials, including viscoelastic composite materials. Applications of viscoelasticity and viscoelastic materials are illustrated with case studies.

This concise introduction to the concepts of viscoelasticity focuses on stress analysis.

Author: D. R. Bland

Publisher: Courier Dover Publications

ISBN: 9780486816388

Category: Technology & Engineering

Page: 144

View: 328

This concise introduction to the concepts of viscoelasticity focuses on stress analysis. Three detailed sections present examples of stress-related problems, including sinusoidal oscillation problems, quasi-static problems, and dynamic problems. 1960 edition.

Viscoelasticity. —. Elastic. Dumbbell. Model. 6.1 Introduction In Chapter 3, we
used the Rouse model for a polymer chain to study the diffusion motion and the
time-correlation function of the end-to-end vector. The Rouse model was first ...

Author: Y.-H. Lin

Publisher: World Scientific

ISBN: 9812384170

Category: Technology & Engineering

Page: 251

View: 197

In this book, the studies of the Rouse, Doi?Edwards, and extended reptation theories are developed in a consistent manner from a basic level and discussed in detail. Viscoelastic properties of nearly monodisperse linear flexible polymers in both the entanglement and entanglement-free regions are analyzed quantitatively in terms of the molecular theories.

This book contains notes for a one-semester graduate course which is an introduction to the study of viscoelasticity and creep of concrete.

Author: Guillermo J. Creus

Publisher: Springer Science & Business Media

ISBN: 9783642826863

Category: Technology & Engineering

Page: 169

View: 792

This book contains notes for a one-semester graduate course which is an introduction to the study of viscoelasticity and creep of concrete. Emphasis was set on the conceptual aspects rather than on the mathematical or computational refinements. The mathematical structure of viscoelasticity is discussed with some care because it clarifies the basic concepts and has important consequences in computa tional applications. Basic ideas are exemplified using the simplest problems and constitutive models in order to be able to show complete solutions. In the computational applications we have also chosen to present the sim plest situations with the greatest possible detail. It has been the author's experience that once the basic concepts are well understood the students are able to follow the rest of the course more easily and to accede to more advanced literature and applications. Chapters I to III furnish the foundations for the course, that may be expanded in diverse ways. If we are interested in finite elements applications we should look at Chapter IV and then go direct ly to Chapter VII. If we are interested in the simplified analysis of frame structures we should study Chapter VI in detail. Chapter V re views the viscoelastic behavior of concrete and Chapter VIII studies the problem of creep buckling. At the end of each chapter we give se lected references to works that complete and extend the subject matter.

troducing natural modifications into established theories such as finite elasticity ,
classical fluid dynamics , or linear viscoelasticity . From a physical point of view ,
the complexity of viscoelastic behavior results from the dynamics of the long ...

Author: Severino P. C. MarquesPublish On: 2012-01-03

This text is a guide how to solve problems in which viscoelasticity is present using existing commercial computational codes.

Author: Severino P. C. Marques

Publisher: Springer Science & Business Media

ISBN: 9783642253102

Category: Mathematics

Page: 124

View: 177

This text is a guide how to solve problems in which viscoelasticity is present using existing commercial computational codes. The book gives information on codes’ structure and use, data preparation and output interpretation and verification. The first part of the book introduces the reader to the subject, and to provide the models, equations and notation to be used in the computational applications. The second part shows the most important Computational techniques: Finite elements formulation, Boundary elements formulation, and presents the solutions of Viscoelastic problems with Abaqus.

Assuming that the WLF equation does indeed describe the time—temperature
shifts, the complete viscoelastic response of any polymer under any experimental
conditions may be obtained from knowledge of any two of the following three ...

Author: Montgomery T. Shaw

Publisher: John Wiley & Sons

ISBN: 9780471741824

Category: Technology & Engineering

Page: 336

View: 870

A revised molecular approach to a classic on viscoelasticbehavior Because viscoelasticity affects the properties, appearance,processing, and performance of polymers such as rubber, plastic,and adhesives, a proper utilization of such polymers requires aclear understanding of viscoelastic behavior. Now in its third edition, Introduction to Polymer Viscoelasticityremains a classic in the literature of molecular viscoelasticity,bridging the gap between primers on polymer science and advancedresearch-level monographs. Assuming a molecular, rather than amechanical approach, the text provides a strong grounding in thefundamental concepts, detailed derivations, and particularattention to assumptions, simplifications, and limitations. This Third Edition has been entirely revised and updated to reflectrecent developments in the field. New chapters include: * Phenomenological Treatment of Viscoelasticity * Viscoelastic Models * Time-Temperature Correspondence * Transitions and Relaxation in Polymers * Elasticity of Rubbery Networks * Dielectric and NMR Methods With detailed explanations, corresponding equations, andexperimental methods, supported by real-life applications (as wellas the inclusion of a CD-ROM with data to support the exercises),this Third Edition provides today's students and professionals withthe tools they need to create polymers with more desirablequalities than ever.

VISCOELASTICITY MODELS FOR RUBBER 4.1 Introduction The large strain viscoelastic models of rubber used by solid mechanics analysts are purely
phenomenological . More physically based models are examined which more
directly ...

The flexion of viscoelastic beams and the torsion of viscoelastic rods are studied
in this chapter . 17.2 BEAM BENDING : PRELIMINARY HYPOTHESES AND
STRESS TENSOR In a first approach to the study of beam bending , it is
convenient ...

Author: Evaristo Riande

Publisher: CRC Press

ISBN: 0824779045

Category: Technology & Engineering

Page: 904

View: 280

Showcasing vital engineering applications to transient and dynamic pertubations of macromolecular materials, structural recovery's role in mechanical responses in the glassy state, and viscoelastic parameters that condition the non-Newtonian behaviour of polymers, this work presents a systematic account of the responses of macromolecular materials to mechanical force fields. It focuses on the most important features of the linear stress-strain relationships for ideal solids and liquids.

If the ratio is negligibly small , then one has a viscous fluid ( more precise
definition later ) , if it is large , a solid , and in - between , a viscoelastic liquid .
The time scale ratio , De = T / T is called the Deborah number . The time scale of
the fluid ...

Author: Nhan Phan-Thien

Publisher: Springer Science & Business Media

ISBN: 3540433953

Category: Technology & Engineering

Page: 146

View: 692

In this book, the necessary background for understanding viscoelasticity is covered; both the continuum and microstructure approaches to modelling viscoelastic materials are discussed, since neither approach alone is sufficient.

TABLE OF CONTENTS iii ACKNOWLEDGMENT LIST OF ILLUSTRATIONS vi
CHAPTER I : INTRODUCTION CHAPTER II : STRESS STRAIN RELATIONS FOR VISCOELASTIC MATERIALS 32 . 32 CHAPTER III : DIFFERENTIAL EQUATIONS
...

A typical process of the second kind is provided by the one-dimensional
propagation of stress pulses in a linear viscoelastic medium with constant Q,
which is quite relevant in seismology. This process is indeed governed by an
evolution ...

Author: Francesco Mainardi

Publisher: World Scientific

ISBN: 9781848163300

Category: Mathematics

Page: 368

View: 964

This monograph provides a comprehensive overview of the author's work on the fields of fractional calculus and waves in linear viscoelastic media, which includes his pioneering contributions on the applications of special functions of the Mittag-Leffler and Wright types. It is intended to serve as a general introduction to the above-mentioned areas of mathematical modeling. The explanations in the book are detailed enough to capture the interest of the curious reader, and complete enough to provide the necessary background material needed to delve further into the subject and explore the research literature given in the huge general bibliography. This book is likely to be of interest to applied scientists and engineers.

Preface A symposium on phenomenological aspects of viscoelasticity was held
on April 28 and 29, 1958, at the Research and Development Center of the
Armstrong Cork Company, Lancaster, Pennsylvania. The seven papers
presented at ...

Author: J. T. Bergen

Publisher: Academic Press

ISBN: 9781483261768

Category: Science

Page: 160

View: 202

Viscoelasticity: Phenomenological Aspects provides information pertinent to the phenomenological aspects of viscoelasticity. This book provides the basic approach to the behavioral description of viscoelasticity. Organized into seven chapters, this book begins with an overview of the development of various theories of linear viscoelastic theories. This text then presents the results of investigation that evaluate the linear viscoelastic parameters of typical polymeric materials. Other chapters consider the development of nonlinear stress-strain-time relations for viscoelastic materials, which have been helpful in the analysis of the linear mechanical behavior of rubberlike polymers and the molecular theories. This book discusses as well the application of linear theories and the behavior of a number of polymer systems and their similarities and differences. The final chapter deals with experimental observations of real materials that exhibit nonlinear, time-dependent stress-strain behavior. This book is a valuable resource for chemists, mechanical engineers, and research workers.

Author: Danton Gutierrez-LeminiPublish On: 2013-09-12

Not surprisingly, these materials are called viscoelastic and are a little trickier to
understand than elastic solids or viscous fluids. The engineering discipline that
developed to provide a rigorous mathematical framework to describe the
behavior ...

Author: Danton Gutierrez-Lemini

Publisher: Springer Science & Business Media

ISBN: 9781461481393

Category: Technology & Engineering

Page: 353

View: 961

Engineering Viscoelasticity covers all aspects of the thermo- mechanical response of viscoelastic substances that a practitioner in the field of viscoelasticity would need to design experiments, interpret test data, develop stress-strain models, perform stress analyses, design structural components, and carry out research work. The material in each chapter is developed from the elementary to the esoteric, providing the background in mathematics and mechanics that are central to understanding the subject matter being presented. This book also examines how viscoelastic materials respond to the application of loads, and provides practical guidelines to use them in the design of commercial, military and industrial applications.

1 Introduction Given that there is a paucity in the literature in the studies of
stability characteristics of free surface viscoelastic displacement flows , the main
objective of this study is to perform a rigorous stability analysis of a viscoelastic
two ...