Superplasticity is the ability of polycrystalline materials under certain conditions to exhibit extreme tensile elongation in a nearly homogeneous/isotropic manner. Historically, this phenomenon was discovered and systematically studied by metallurgists and physicists. They, along with practising engineers, used materials in the superplastic state for materials forming applications. Metallurgists concluded that they had the necessary information on superplasticity and so theoretical studies focussed mostly on understanding the physical and metallurgi cal properties of superplastic materials. Practical applications, in contrast, were led by empirical approaches, rules of thumb and creative design. It has become clear that mathematical models of superplastic deformation as well as analyses for metal working processes that exploit the superplastic state are not adequate. A systematic approach based on the methods of mechanics of solids is likely to prove useful in improving the situation. The present book aims at the following. 1. Outline briefly the techniques of mechanics of solids, particularly as it applies to strain rate sensitive materials. 2. Assess the present level of investigations on the mechanical behaviour of superplastics. 3. Formulate the main issues and challenges in mechanics ofsuperplasticity. 4. Analyse the mathematical models/constitutive equations for superplastic flow from the viewpoint of mechanics. 5. Review the models of superplastic metal working processes. 6. Indicate with examples new results that may be obtained using the methods of mechanics of solids.

Publisher Description

VISCOPLASTIC FLOW IN SOLIDS PRODUCED BYSHEAR BANDING A complete overview of the topic of viscoplastic flow in solids produced by shear banding This book presents novel ideas about inelastic deformation and failure of solids in a clear, concise manner. It exposes readers to information that will allow them to acquire the competence and ability to deal with up-to-date manufacturing and failure processes. It also portrays a new understanding of deformation processes. Finally, shear banding’s typical mechanism becomes the active cause of viscoplastic flow and not the ­passive effect. Viscoplastic Flow in Solids Produced by Shear Banding begins by discussing the new physical model of multilevel hierarchy and the evolution of micro-shear bands. In conclusion, it examines the difficulties of applying a direct multiscale integration scheme and extends the representative volume element (RVE) concept using the general theory of the singular surfaces of the microscopic velocity field sweeping out the RVE. This book reveals a new formulation of the shear strain rate generated by the consecutive systems of shear bands in the workflow integration approach. This book: Presents fresh ideas about inelastic deformation and failure of materials Provides readers with the ability to deal with up-to-date manufacturing and failure processes Sheds light on the interdisciplinary view of deformation processes in solids Viscoplastic Flow in Solids Produced by Shear Banding will appeal to researchers studying physical foundations of inelastic behaviour and failure of solid materials, dealing with analysis and numerical simulations of manufacturing forming processes. It is also an excellent resource for graduate and postgraduate students of material science and mechanical engineering faculties.

This volume of scientific papers is dedicated with gratitude and esteem to Ronald Rivlin and is offered as a token of appreciation by former students, col laborators, and friends. Ronald Rivlin's name is synonymous with modem developments in contin uum mechanics. His outstanding pioneering theoretical and experimental re ·search in finite elasticity is a landmark. From his work there has followed a spate of developments in which he played the leading role-the theory of fiber-rein forced materials, the developments of the theory of constitutive equations, the theory of materials with memory, the theory of the fracture of elastomers, the theory of viscoelastic fluids and solids, the development of nonlinear crystal physics, the theory of small deformations superimposed on large, and the effect of large initial strain on wave propagation. It is in Rivlin's work that universal relations were first recognized. Here also are to be found lucid explanations of physical phenomena such as the Poynting effect for elastic rods in torsion. Addi tionally, he and his co-workers predicted the presence of secondary flows for viscoelastic fluids in straight pipes of noncircular cross section under a uniform pressure head. While some others may have displayed a cavalier lack of concern for physical reality and an intoxication with mathematical idiom, Rivlin has al ways been concerned with genuine mathematical and physical content. All of his papers contain interesting and illuminating material-and may be read with profit by anyone interested in continuum mechanics.

This book contains contributions by sixteen editors of a single journal specialised in real-world applications of mathematics, particularly in engineering. These papers serve to indicate that applying mathematics can be a very exciting and intellectually rewarding activity. Among the applied fields we note Thermal and Marangoni convection. High-pressure gas-discharge lamps, Potential flow in a channel, Thin airfoil problems, Cooling of a fibre, Moving-contact-line problems, Spot disturbance in boundary layers, Fibre-reinforced composites, Numerics of nonuniform grids, Stewartson layers on a rotating disk, Causality and the radiation condition, Nonlinear elastic membranes, Acoustics in bubbly liquids, Oscillation of a floating body in a viscous fluid, Electromagnetics of superconducting composites. Applied mathematicians, theoretical physicists and engineers will find a lot in this book that will be of interest to them.

The 45 papers presented in this volume all share the common goal of constructing continuum models based on the micro behaviours of granular materials. Computer simulations continue to provide observations to aid modelling, while new experimental works begin to show promise for increased understanding in this area. Theoretical studies have extended into transitions between the rapid and quasi-static regimes and the fluid and solid mixture flows. Exciting new topics discussed in this volume include: concepts of a measure for randomness in quasi-static granular materials, which is analogous to the granular temperature in a rapid flow; scaling effects in granular media and their implications in both physical and computer simulations; instability; and boundary effects on heterogeneous behavior in simple flow configurations, which are posing new challenges for mathematical modelling. The volume will prove indispensable reading for researchers interested in the current developments in the fundamental aspects of mechanics of granular materials.