Viscoelastic Materials

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

This pioneering book presents the basic theory, experimental methods, experimental results and solution of boundary value problems in a readable, useful way to designers as well as research workers and students. The mathematical background required has been kept to a minimum and supplemented by explanations where it has been necessary to introduce specialized mathematics. Also, appendices have been included to provide sufficient background in Laplace transforms and in step functions. Chapters 1 and 2 contain an introduction and historic review of creep. As an aid to the reader a background on stress, strain, and stress analysis is provided in Chapters 3 and 4, an introduction to linear viscoelasticity is found in Chapter 5 and linear viscoelastic stress analysis in Chapter 6. In the next six chapters the multiple integral representation of nonlinear creep and relaxation, and simplifications to single integral forms and incompressibility, are examined at length. After a consideration of other representations, general relations are derived, then expanded to components of stress or strain for special cases. Both constant stress (or strain) and variable states are described, together with methods of determining material constants. Conversion from creep to relaxation, effects of temperature and stress analysis problems in nonlinear materials are also treated here. Finally, Chapter 13 discusses experimental methods for creep and stress relaxation under combined stress. This chapter considers especially those experimental problems which must be solved properly when reliable experimental results of high precision are required. Six appendices present the necessary mathematical background, conversion tables, and more rigorous derivations than employed in the text. An extensive updated bibliography completes the book.

The enormous size of polymer molecules causes their molecular motions to span a broad range of length scales and give rise to viscoelastic behaviour. This rate-dependence of the properties is a predominant characteristic of soft materials (rubbers, biopolymers, lubricants, adhesives, etc.). Improving the performance and developing new applications for soft materials require an understanding of the basic principles of how molecular motions underlie physical properties. This text is intended to provide grounding in fundamental aspects of the dynamic behavior of rubbery materials, adopting a molecular perspective in its treatment to emphasize how microscopic processes are connected to the observed macroscopic behavior. The latest discoveries and advances in the science and technology of rubbery materials are described and critically analyzed.

The damping characteristics of a temperature independent viscoelastic material are determined under axial, shear, and several combinations of both axial and shear loadings. A method for measuring these properties is devised by considering a double lap joint specimen and measuring the area of the hysteresis loops which resulted from the cyclic loading of the specimen under axial, shear, and several combinations of both axial and shear conditions. The complex elastic and shear moduli and Poisson's ratio are presented as a function of the strain amplitude. The experimental results of the damping properties under biaxial stresses are found to be in good agreement with the theoretical analysis. (Author).

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.

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.

Viscoelasticity is a complicated theorem that is generally used in several aspects of material characterization and modeling of polymers, resins, fiber-reinforced composites, bituminous composites, etc. On the other hand, the heterogeneous nature of composites like asphalt concrete and fiber-reinforced polymers has motivated lots of researchers to investigate the mechanical and rheological properties of these materials. This book mainly consists of the theory and application of viscoelastic materials used for construction. It starts with a comprehensible presentation of the theory of linear and nonlinear viscoelasticity. Wherein, the application of viscoelastic equations and principles on constructional viscoelastic composite materials considering time, temperature, loading rate dependency, and heterogeneity of composite substances is highlighted. The principles and equations of the viscoelasticity theorem are presented in several books, but here it is tried to present them more understandable and straightforwardly. This helps in solving real problems of heterogeneous composite materials, especially those which are used in construction. Moreover, the fundamental experiments for characterizing the elastic and viscoelastic properties of fibrous and bituminous composites are introduced and summarized. Then after, some analytical and empirical formulations for deriving the material properties of composites from the properties of the basic constituents are presented. These are followed by numerical simulation techniques using the finite element method to simulate composite materials.

This book introduces numerous selected advanced topics in viscoelastic and viscoplastic materials. The book effectively blends theoretical, numerical, modeling and experimental aspects of viscoelastic and viscoplastic materials that are usually encountered in many research areas such as chemical, mechanical and petroleum engineering. The book consists of 14 chapters that can serve as an important reference for researchers and engineers working in the field of viscoelastic and viscoplastic materials.