This textbook offers readers an introduction to fracture mechanics, equipping them to grasp the basic ideas of the presented approaches to modeling in applied mechanics In the first part, the book reviews and expands on the classical theory of elastic and elasto-plastic material behavior. A solid understanding of these two topics is the essential prerequisite to advancing to damage and fracture mechanics. Thus, the second part of this course provides an introduction to the treatment of damage and fractures in the context of applied mechanics Wherever possible, the one-dimensional case is first introduced and then generalized in a following step. This departs somewhat from the more classical approach, where first the most general case is derived and then simplified to special cases. In general, the required mathematics background is kept to a minimum Tutorials are included at the end of each chapter, presenting the major steps for the solution and offering valuable tips and tricks. The supplementary problems featured in the book
Recent developments in engineering and technology have brought about serious and enlarged demands for reliability, safety and economy in wide range of fields such as aeronautics, nuclear engineering, civil and structural engineering, automotive and production industry. This, in turn, has caused more interest in continuum damage mechanics and its engineering applications. This book aims to give a concise overview of the current state of damage mechanics, and then to show the fascinating possibility of this promising branch of mechanics, and to provide researchers, engineers and graduate students with an intelligible and self-contained textbook. The book consists of two parts and an appendix. Part I is concerned with the foundation of continuum damage mechanics. Basic concepts of material damage and the mechanical representation of damage state of various kinds are described in Chapters 1 and 2. In Chapters 3-5, irreversible thermodynamics, thermodynamic constitutive theory and its application to the modeling of the constitutive and the evolution equations of damaged materials are descried as a systematic basis for the subsequent development throughout the book. Part II describes the application of the fundamental theories developed in Part I to typical damage and fracture problems encountered in various fields of the current engineering. Important engineering aspects of elastic-plastic or ductile damage, their damage mechanics modeling and their further refinement are first discussed in Chapter 6. Chapters 7 and 8 are concerned with the modeling of fatigue, creep, creep-fatigue and their engineering application. Damage mechanics modeling of complicated crack closure behavior in elastic-brittle and composite materials are discussed in Chapters 9 and 10. In Chapter 11, applicability of the local approach to fracture by means of damage mechanics and finite element method, and the ensuing mathematical and numerical problems are briefly discussed. A proper understanding of the subject matter requires knowledge of tensor algebra and tensor calculus. At the end of this book, therefore, the foundations of tensor analysis are presented in the Appendix, especially for readers with insufficient mathematical background, but with keen interest in this exciting field of mechanics.
Modern engineering materials subjected to unfavorable mechanical and environmental conditions decrease in strength due to the accumulation of microstructural changes. For example, considering damage in metals we can mention creep damage, ductile plastic damage, embrittlement of steels and fatigue damage. To properly estimate the value of damage when designing reliable structures it is necessary to formulate the damage phenomenon in terms of mechanics. Then it is possible to analyse various engineering problems using analytical and computational techniques. During the last two decades the basic principles of continuum damage mechanics were formulated and some special problems were solved. Many scientific papers were published and several conferences on damage mechanics took place. Now continuum damage mechanics is rapidly developing branch of fracture mechanics. This book is probably the first one on the subject; it contains a sys tematic description of the basic aspects of damage mechanics and some of its applications. In general, a theoretical description of damage can be rather compli cated. The experiments in this field are difficult (especially under multiax ial stress and non-proportional loading). Therefore, experimental data, as a rule, are scarce. Determination of functions and constants, which play a role in the complex variants of the theory, from available experimental data is often practically impossible. ix L.M. Kachanov The problems of damage mechanics are mainly engineering ones. Therefore, the author tries to avoid superfluous mathematical formalism. Some more details of the book's subject can be found in the list of con tents.
A new branch of science usually develops thus. Somebody publishes the basic ideas. Hesitatingly at first, then little by little, other original contributions appear, until a certain threshold is reached. Then, overview articles are printed, conferences are held, and a first mention is made in textbooks, until specialized monographs are written. Continuum darnage mechanics has reached that status now. To analyze or, if possible, to predict the failure of machine parts or other structures is one of the main goals of engineering science. Consequently fracture mechanics became one of its leading branches. It was based on the analysis of existing cracks. However, especially under conditions of cyclic loading, this might be too late to prevent a disaster. Therefore, the question regarding the precursory state, that is, the evolution of intemal darnage before macrocracks become visible, was then posed. One of the successful approaches to the problern was Weibull's theory which examined, in a statistical manner, the "weakest link" in the material volume under consideration. Unfortunately it proved too difficult mathematically to be applied to complicated parts or structures. Therefore it was highly appreciated by the scientific of material community when L. M. Kachanov published in 1958 a simple model darnage which subsequently could be extended to brittle elastic, plastic or viscous materials under all conditions of uniaxial or multiaxial, simple or cyclic loadings, so that it may be considered nearly universal.
Created in 1975, LMT-Cachan is a joint laboratory École Normale Superieure de Cachan, Pierre & Marie Curie (Paris 6) University and the French Research Council CNRS (Department of Engineering Sciences).The Year 2000 marked the 25th anniversary of LMT. On this occasion, a series of lectures was organized in Cachan in September-October, 2000. This publication contains peer-reviewed proceedings of these lectures and is aimed to present engineers and scientists with an overview of the latest developments in the field of damage mechanics. The formulation of damage models and their identification procedures were discussed for a variety of materials.
- self-contained and well illustrated - complete and comprehensive derivation of mechanical/mathematical results with enphasis on issues of practical importance - combines classical subjects of fracture mechanics with modern topics such as microheterogeneous materials, piezoelectric materials, thin films, damage - mechanically and mathematically clear and complete derivations of results
Reflecting his major contributions to the field, Jean Lemaitre’s "Engineering Damage Mechanics" presents simplified and advanced methods organized within a unified framework for designers of any mechanical component. Explains how to apply continuous damage mechanics to failures of mechanical and civil engineering components in ductile, creep, fatigue and brittle conditions. Incorporates many basic examples, while emphasizing key practical considerations such as material parameter identification, and provides perspective on the advantage and disadvantages of various approaches.
This volume presents a collection of contributions on advanced approaches of continuum mechanics, which were written to celebrate the 60th birthday of Prof. Holm Altenbach. The contributions are on topics related to the theoretical foundations for the analysis of rods, shells and three-dimensional solids, formulation of constitutive models for advanced materials, as well as development of new approaches to the modeling of damage and fractures.
- self-contained and well illustrated - complete and comprehensive derivation of mechanical/mathematical results with enphasis on issues of practical importance - combines classical subjects of fracture mechanics with modern topics such as microheterogeneous materials, piezoelectric materials, thin films, damage - mechanically and mathematically clear and complete derivations of results
This book derives from the invited IUTAM Symposium in September 1993. The contributions discuss recent advances in fracture mechanics studies of concrete, rock, ceramics and other brittle disordered materials at micro and structural levels. It draws together research and new applications in continuum, damage and fracture mechanics approaches.
