Search results for: continuum-damage-and-fracture-mechanics

Continuum Damage and Fracture Mechanics

Author : Andreas Öchsner
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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

Continuum Damage Mechanics

Author : Sumio Murakami
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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.

Introduction to continuum damage mechanics

Author : L. Kachanov
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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.

Applications of Continuum Damage Mechanics to Fatigue and Fracture

Author : David L. McDowell
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Contains papers from the May 1996 Symposium on Applications of Continuum Damage Mechanics (CDM) to Fatigue and Fracture. Papers in Section I deal with various aspects of modeling damage in composite materials, such as high temperature environmental degradation, fatigue, and viscous damage in metal a

Continuum Damage Mechanics and Numerical Applications

Author : Wohua Zhang
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"Continuum Damage Mechanics and Numerical Applications" presents a systematic development of the theory of Continuum Damage Mechanics and its numerical engineering applications using a unified form of the mathematical formulations in anisotropic and isotropic damage models. The theoretical framework is based on the thermodynamic theory of energy and material dissipation and is described by a set of fundamental formulations of constitutive equations of damaged materials, development equations of the damaged state, and evolution equations of micro-structures. According to concepts of damage-dissipation of the material state and effective evolution of material properties, all these advanced equations, which take nonsymmetrized effects of damage aspects into account, are developed and modified from the traditional general failure models so they are more easily applied and verified in a wide range of engineering practices by experimental testing. Dr. Wohua Zhang is a Professor at Engineering Mechanics Research Center in Zhejiang University of China. Dr. Yuanqiang Cai is a Professor at Department of Civil Engineering in Zhejiang University of China.

Continuum Damage Mechanics of Materials and Structures

Author : O. Allix
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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.

Continuum Damage Mechanics Theory and Application

Author : Dusan Krajcinovic
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Continuum Damage Mechanics Approach to Ductile Fracture

Author : Mubarak ALGrafi
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Failure of ductile materials such as structural steel is associated with large amount of plastic deformation. Ductile fracture is characterized by three sequential processes; void nucleation, void growth, and void coalescence. Continuum Damage Mechanics (CDM) has emerged as attractive approach for predicting nucleation and growth of cracks in ductile materials. However, comprehensive satisfactory CDM model, which can describe the different physical stages of ductile fracture, has not been formulated yet. In addition, coalescence stage has received less attention compared to void nucleation and growth. In this book, elasto-plastic damage softening models are formulated (unified) into one complete damage softening model. Numerical simulation using LS-DYNA explicit solver carried out utilizing user defined material (UMAT). Return mapping algorithm used as the main numerical tool in updating stress in the plastic regime. Validity of this work is examined by comparison with experimental data for available crack path. Finally, evaluation of J-integral for the damage softening models has been accomplished for the purpose of establishing link between Fracture Mechanics & Damage Mechanics.

Fracture Mechanics

Author : Dominique P. Miannay
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Intended for engineers from a variety of disciplines dealing with structural materials, this text describes the current state of knowledge. It begins by describing the fracture process at the two extremes of scale: first in the context of atomic structures, then in terms of a continuous elastic medium. Treating the fracture process in increasingly sophisticated ways, the book then considers plastic corrections and the procedures for measuring the toughness of materials. Practical considerations are then discussed, including crack propagation, geometry dependence, flaw density, mechanisms of failure by cleavage, the ductile-brittle transition, and continuum damage mechanics. The whole is rounded off with discussions of generalised plasticity and the link between the microscopic and macroscopic aspects, and problems are provided at the end of each chapter.

Mechanics of Fatigue

Author : Vladimir V. Bolotin
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Mechanics of Fatigue addresses the range of topics concerning damage, fatigue, and fracture of engineering materials and structures. The core of this resource builds upon the synthesis of micro- and macro-mechanics of fracture. In micromechanics, both the modeling of mechanical phenomena on the level of material structure and the continuous approach are based on the use of certain internal field parameters characterizing the dispersed micro-damage. This is referred to as continuum damage mechanics. The author develops his own theory for macromechanics, called analytical fracture mechanics. This term means the system cracked body - loading or loading device - is considered as a mechanical system and the tools of analytical (rational) mechanics are applied thoroughly to describe crack propagation until the final failure. Chapter discuss: preliminary information on fatigue and engineering methods for design of machines and structures against failures caused by fatigue fatigue crack nucleation, including microstructural and continuous models theory of fatigue crack propagation fatigue crack growth in linear elastic materials subject to dispersed damage fatigue cracks in elasto-plastic material, including crack growth retardation due to overloading as well as quasistationary approximation fatigue and related phenomena in hereditary solids application of the theory fatigue crack growth considering environmental factors unidirectional fiber composites with ductile matrix and brittle, initially continuous fibers laminate composites Mechanics of Fatigue serves students dealing with mechanical aspects of fatigue, conducting research in fracture mechanics, structural safety, mechanics of composites, as well as modern branches of mechanics of solids and structures.

Damage and Fracture of Disordered Materials

Author : Dusan Krajcinovic
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The principal objective of this book is to relate the random distributions of defects and material strength on the microscopic scale with the deformation and residual strength of materials on the macroscopic scale. To reach this goal the authors considered experimental, analytical and computational models on atomic, microscopic and macroscopic scales.

Mechanics of Fatigue

Author : Vladimir Vasilʹevich Bolotin
File Size : 81.40 MB
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Mechanics of Fatigue addresses the range of topics concerning damage, fatigue, and fracture of engineering materials and structures. The core of this resource builds upon the synthesis of micro- and macro-mechanics of fracture. In micromechanics, both the modeling of mechanical phenomena on the level of material structure and the continuous approach are based on the use of certain internal field parameters characterizing the dispersed micro-damage. This is referred to as continuum damage mechanics.The author develops his own theory for macromechanics, called analytical fracture mechanics. This term means the system cracked body - loading or loading device - is considered as a mechanical system and the tools of analytical (rational) mechanics are applied thoroughly to describe crack propagation until the final failure.Chapter discuss:preliminary information on fatigue and engineering methods for design of machines and structures against failures caused by fatiguefatigue crack nucleation, including microstructural and continuous modelstheory of fatigue crack propagationfatigue crack growth in linear elastic materials subject to dispersed damagefatigue cracks in elasto-plastic material, including crack growth retardation due to overloading as well as quasistationary approximationfatigue and related phenomena in hereditary solidsapplication of the theory fatigue crack growth considering environmental factorsunidirectional fiber composites with ductile matrix and brittle, initially continuous fiberslaminate compositesMechanics of Fatigue serves students dealing with mechanical aspects of fatigue, conducting research in fracture mechanics, structural safety, mechanics of composites, as well as modern branches of mechanics of solids and structures.

Creep and Damage in Materials and Structures

Author : Holm Altenbach
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This textbook gives a concise survey of constitutive and structural modeling for high temperature creep, damage, low – cycle fatigue and other inelastic conditions. The book shows the creep and continuum damage mechanics as rapidly developing discipline which interlinks the material science foundations, the constitutive modeling and computer simulation application to analysis and design of simple engineering components. It is addressed to young researchers and scientists working in the field of mechanics of inelastic, time-dependent materials and structures, as well as to PhD students in computational mechanics, material sciences, mechanical and civil engineering.

Creep Rupture Investigation of 63Sn 37Pb Solder by Experiments and Damage Mechanics

Author : S-H Ju
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The main purpose of this paper is to investigate the crack growth path and creep rupture life of 63Sn-37Pb bulk solder experimentally by Moiré analysis and theoretically using continuum damage mechanics. In conventional fracture mechanics analysis, a crack growth path is assumed a priori. Fracture parameters such as the J-integral and stress intensity factor are subsequently calculated to predict the crack growth rate and structural life. However, it is often difficult to postulate the correct crack growth path for a complex structure that is subject to complex loading. Continuum damage mechanics is an alternative method that can be used to compute structural life with the important feature that the crack growth path is computed automatically. In this paper we develop a theory for partially reversible creep-fatigue damage. A finite element procedure incorporating this damage theory is developed and used to analyze the response of bulk solder plates with holes. The displacement fields obtained by finite element analysis are compared to the fringe patterns obtained from conventional Moiré experiments. Furthermore, the accuracy of the predicted crack growth paths was investigated by comparison between the maximum damage contours obtained by finite element simulation with the actual crack paths occurring in the laboratory specimens. These comparisons indicate the new continuum damage theory developed herein can adequately predict creep displacements, crack growth paths, and structural life.

Damage Mechanics in Engineering Materials

Author : Jiann-Wen Woody Ju
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This book contains thirty peer-reviewed papers that are based on the presentations made at the symposium on "Damage Mechanics in Engineering Materials" on the occasion of the Joint ASME/ASCE/SES Mechanics Conference (McNU97), held in Evanston, Illinois, June 28-July 2, 1997. The key area of discussion was on the constitutive modeling of damage mechanics in engineering materials encompassing the following topics: macromechanics/micromechanical constitutive modeling, experimental procedures, numerical modeling, inelastic behavior, interfaces, damage, fracture, failure, computational methods. The book is divided into six parts: Study of damage mechanics. Localization and damage. Damage in brittle materials. Damage in metals and metal matrix composites. Computational aspects of damage models. Damage in polymers and elastomers.

DEVELOPMENT OF AN ANISOTROPIC

Author : 王軍
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This dissertation, "Development of an Anisotropic Damage Mechanics Model in Ductile Fracture" by 王軍, Chun, Wang, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. DOI: 10.5353/th_b3123137 Subjects: Fracture mechanics Continuum damage mechanics

Damage Mechanics and Micromechanics of Localized Fracture Phenomena in Inelastic Solids

Author : George Z Voyiadjis
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This book resulted from a series of lecture notes presented in CISM, Udine in July 7 -11, 2008. The papers inform about recent advances in continuum damage mechanics for both metals and metal matrix composites as well as the micromechanics of localization in inelastic solids. Also many of the different constitutive damage models that have recently appeared in the literature and the different approaches to this topic are presented, making them easily accessible to researchers and graduate students in civil engineering, mechanical engineering, engineering mechanics, aerospace engineering, and material science.

Fracture Mechanics

Author : Dietmar Gross
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- 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

A Course on Damage Mechanics

Author : Jean Lemaitre
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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.

Dynamic Brittle Fracture Analysis Based on Continuum Damage Mechanics

Author : E-P Chen
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The dynamic response of materials with existing flaw structures is the subject of the present investigation. In this paper, the cracked solid is described by a constitutive model based on continuum damage mechanics. The purpose of the analysis is to show that the constitutive model can predict many of the experimentally observed phenomena in these materials. This is demonstrated by treating a sample problem. The geometry and loading condition selected for this sample problem is that of a 45-deg inclined crack, centrally situated in a concrete panel and subjected to the action of a step tensile pulse. Damage localization and tension-softening have been observed. These results and their implications are discussed.