Properties for Design of Composite Structures. Neil McCartney

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Название Properties for Design of Composite Structures
Автор произведения Neil McCartney
Жанр Техническая литература
Серия
Издательство Техническая литература
Год выпуска 0
isbn 9781118789780



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used in their manufacture (e.g. reinforcements and matrix) and on the geometrical arrangement of these materials. It is plainly not feasible to undertake an experimental programme designed to use measurement methods to determine the relationships between effective properties of composite materials and the constituent properties and structure. Instead, theoretical methods are used based on the well-established principles of continuum thermodynamics defined in its most general form so that both continuum mechanics and electrodynamics are considered in a thermodynamic context. It is indeed of interest to know that James Clerk Maxwell, developer of the famous Maxwell equations of electrodynamics, is believed to be the first scientist to develop a formula for an effective property of a composite material. He considered a cluster of spherical particles, all having the same isotropic permittivity value, embedded in an infinite matrix, having a different value for isotropic permittivity, and developed an elegant method of estimating the effective properties of the particle cluster. Although Maxwell argued that his neglect of particle interactions would limit the validity of his effective property to low volume fractions, it is known that results obtained using his methodology are in fact valid for much larger volume fractions. This important scientific contribution appeared in 1873 as part of Chapter 9 in his book entitled A Treatise on Electricity and Magnetism, published by Clarendon Press, Oxford. Maxwell’s methodology will be used in this book to help understand the relationship of many effective composite properties to the properties of the reinforcements and their geometrical arrangements within a matrix.

      The principal objectives of this book are to present, in a single publication, a description of the derivations of selected theoretical methods of predicting the effective properties of composite materials for situations where they are either undamaged or are subject to damage in the form of matrix cracking, in fibre-reinforced unidirectional composites, or in the plies of laminates, or to a lesser extent on the interfaces between neighbouring plies. The major focus of the book is on derivations of analytical formulae which can be the basis of software that is designed to predict composite behaviour, e.g. prediction of properties and growth of damage and its effect on composite properties. Software will be available from the John Wiley & Sons, Inc. website [1] including examples of software predictions associated with relevant chapters of this book.

      There is no attempt in this book to provide comprehensive accounts of relevant parts of the literature, although reference will be made to source publications related to the analytical methods described in the book. Some topics considered in this book, e.g. the chapters on particulate composites, delamination, fatigue damage and environmental damage, have been included to extend the range of applicability of the analytical methods described in the book. The content of these chapters is based essentially on specific publications by the author that are available in the literature.

      Reference

      1 1. John Wiley & Sons, Inc. website (www.wiley.com/go/mccartney/properties).

      Overview: This chapter introduces the basic principles on which the mechanics of continua are based. Having defined the concepts of vectors and tensors, the physical quantities displacement and velocity are defined for continuous systems and then applied to the fundamental balance laws for mass, momentum (linear and angular) and energy. The principles of the thermodynamics of multicomponent fluid systems are first introduced. The strain tensor is then introduced so that the thermodynamic approach can be extended to solid systems for the single-component solids that will be considered in this book. The fundamental equations are then described for linear thermoelastic solids subject to infinitesimal deformations. The chapter then specifies the constitutive equations required for the analysis of anisotropic solids that will be encountered throughout the book, including the transformation of anisotropic properties following rotation about a given coordinate axis. The chapter concludes by considering bend formation