Download or read book Stress Singularity for a Crack with an Arbitrarily Curved Front written by R. J. Hartranft and published by . This book was released on 1976 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: To investigate the possibility of a point of a crack front propagating in a direction not in the normal plane of the crack front, the three-dimensional form of the crack front stress field is obtained. To simplify comparisons of the states of stress at various points lying on a spherical surface centered at a point of the crack front, a local spherical coordinate system is used. It is found that the crack propagation will be from each point of the crack front in a direction lying in the normal plane. The results are used in conjunction with the strain energy density fracture criterion for the problem of an elliptical crack. The plane of the flat elliptical crack makes an arbitrary angle with the field of uniform applied tensile stress. Crack growth directions for various positoins along the crack front are determined, and loads required for fracture for various angles are obtained. (Author).
Download or read book Solution of Crack Problems written by D.A. Hills and published by Springer Science & Business Media. This book was released on 1996-02-29 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is concerned with the numerical solution of crack problems. The techniques to be developed are particularly appropriate when cracks are relatively short, and are growing in the neighbourhood of some stress raising feature, causing a relatively steep stress gradient. It is therefore practicable to represent the geometry in an idealised way, so that a precise solution may be obtained. This contrasts with, say, the finite element method in which the geometry is modelled exactly, but the subsequent solution is approximate, and computationally more taxing. The family of techniques presented in this book, based loosely on the pioneering work of Eshelby in the late 1950's, and developed by Erdogan, Keer, Mura and many others cited in the text, present an attractive alternative. The basic idea is to use the superposition of the stress field present in the unfiawed body, together with an unknown distribution of 'strain nuclei' (in this book, the strain nucleus employed is the dislocation), chosen so that the crack faces become traction-free. The solution used for the stress field for the nucleus is chosen so that other boundary conditions are satisfied. The technique is therefore efficient, and may be used to model the evolution of a developing crack in two or three dimensions. Solution techniques are described in some detail, and the book should be readily accessible to most engineers, whilst preserving the rigour demanded by the researcher who wishes to develop the method itself.
Download or read book Mechanics of Fracture Initiation and Propagation written by George C. Sih and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: The assessment of crack initiation and/or propagation has been the subject of many past discussions on fracture mechanics. Depending on how the chosen failure criterion is combined with the solution of a particular theory of continuum mechanics, the outcome could vary over a wide range. Mod elling of the material damage process could be elusive if the scale level of observation is left undefined. The specification of physical dimension alone is not sufficient because time and temperature also play an intimate role. It is only when the latter two variables are fixed that failure predictions can be simplified. The sudden fracture of material with a pre-existing crack is a case in point. Barring changes in the local temperature,* the energy released to create a unit surface area of an existing crack can be obtained by considering the change in elastic energy of the system before and after crack extension. Such a quantity has been referred to as the critical energy release rate, G e, or stress intensity factor, K Ie. Other parameters, such as the crack opening displacement (COD), path-independent J-integral, etc. , have been proposed; their relation to the fracture process is also based on the energy release concept. These one-parameter approaches, however, are unable simultaneously to account for the failure process of crack initiation, propagation and onset of rapid fracture. A review on the use of G, K I, COD, J, etc. , has been made by Sih [1,2].
Download or read book Cracked Rotors written by Nicoló Bachschmid and published by Springer Science & Business Media. This book was released on 2010-07-12 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cracks can develop in rotating shafts and can propagate to relevant depths without affecting consistently the normal operating conditions of the shaft. In order to avoid catastrophic failures, accurate vibration analyses have to be performed for crack detection. The identification of the crack location and depth is possible by means of a model based diagnostic approach, provided that the model of the crack and the model of the cracked shaft dynamical behavior are accurate and reliable. This monograph shows the typical dynamical behavior of cracked shafts and presents tests for detecting cracks. The book describes how to model cracks, how to simulate the dynamical behavior of cracked shaft, and compares the corresponding numerical with experimental results. All effects of cracks on the vibrations of rotating shafts are analyzed, and some results of a numerical sensitivity analysis of the vibrations to the presence and severity of the crack are shown. Finally the book describes some crack identification procedures and shows some results in model based crack identification in position and depth. The book is useful for higher university courses in mechanical and energetic engineering, but also for skilled technical people employed in power generation industries.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1977 with total page 1006 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Finite Elements in Fracture Mechanics written by Meinhard Kuna and published by Springer Science & Business Media. This book was released on 2013-07-19 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fracture mechanics has established itself as an important discipline of growing interest to those working to assess the safety, reliability and service life of engineering structures and materials. In order to calculate the loading situation at cracks and defects, nowadays numerical techniques like finite element method (FEM) have become indispensable tools for a broad range of applications. The present monograph provides an introduction to the essential concepts of fracture mechanics, its main goal being to procure the special techniques for FEM analysis of crack problems, which have to date only been mastered by experts. All kinds of static, dynamic and fatigue fracture problems are treated in two- and three-dimensional elastic and plastic structural components. The usage of the various solution techniques is demonstrated by means of sample problems selected from practical engineering case studies. The primary target group includes graduate students, researchers in academia and engineers in practice.
Download or read book Fracture Mechanics in Layered and Graded Solids written by Tian Xiaohong and published by Walter de Gruyter GmbH & Co KG. This book was released on 2014-06-23 with total page 317 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanical responses of solid materials are governed by their material properties. The solutions for estimating and predicting the mechanical responses are extremely difficult, in particular for non-homogeneous materials. Among these, there is a special type of materials whose properties are variable only along one direction, defined as graded materials or functionally graded materials (FGMs). Examples are plant stems and bones. Artificial graded materials are widely used in mechanical engineering, chemical engineering, biological engineering, and electronic engineering. This work covers and develops boundary element methods (BEM) to investigate the properties of realistic graded materials. It is a must have for practitioners and researchers in materials science, both academic and in industry. Covers analysis of properties of graded materials. Presents solutions based methods for analysis of fracture mechanics. Presents two types of boundary element methods for layered isotropic materials and transversely isotropic materials. Written by two authors with extensive international experience in academic and private research and engineering.
Download or read book Proceedings of Crack Paths CP 2009 Vicenza Italy 2009 written by and published by Gruppo Italiano Frattura. This book was released on with total page 1129 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fracture Mechanics Criteria and Applications written by E.E. Gdoutos and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is difficult to do justice to fracture mechanics in a textbook, for the subject encompasses so many disciplines. A general survey of the field would serve no purpose other than give a collection of references. The present book by Professor E. E. Gdoutos is refreshing because it does not fall into the esoteric tradition of outlining equations and results. Basic ideas and underlying principles are clearly explained as to how they are used in application. The presentations are concise and each topic can be understood by advanced undergraduates in material science and continuum mechanics. The book is highly recommended not only as a text in fracture mechanics but also as a reference to those interested in the general aspects of failure analysis. In addition to providing an in-depth review of the analytical methods for evaluating the fundamental quantities used in linear elastic fracture mechanics, various criteria are discussed re:O. ecting their limitations and applications. Par ticular emphases are given to predicting crack initiation, subcritical growth and the onset of rapid fracture from a single criterion. Those models in which it is assumed that the crack extends from tip to tip rely on the specific surface energy concept. The differences in the global and energy states before and after crack extension were associated with the energy required to create a unit area of crack surface. Applications were limited by the requirement of self-similar crack growth.
Download or read book Numerical Methods in Fracture Mechanics written by A. R. Luxmoore and published by . This book was released on 1978 with total page 868 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Fracture Mechanics written by M.H. Aliabadi and published by Springer Science & Business Media. This book was released on 1991-07-31 with total page 296 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this book is to present, describe and demonstrate the use of numerical methods in solving crack problems in fracture mechanics. The text concentrates, to a large extent, on the application of the Boundary Element Method (BEM) to fracture mechanics, although an up-to-date account of recent advances in other numerical methods such as the Finite Element Method is also presented. The book is an integrated presentation of modem numerical fracture mechanics, it contains a compilation of the work of many researchers as well as accounting for some of authors' most recent work on the subject. It is hoped that this book will bridge the gap that exists between specialist books on theoretical fracture mechanics on one hand, and texts on numerical methods on the other. Although most of the methods presented are the latest developments in the field of numerical fracture mechanics, the authors have also included some simple techniques which are essential for understanding the physical principles that govern crack problems in general. Different numerical techniques are described in detail and where possible simple examples are included, as well as test results for more complicated problems. The book consists of six chapters. The first chapter initially describes the historical development of theoretical fracture mechanics, before proceeding to present the basic concepts such as energy balance, stress intensity factors, residual strength and fatigue crack growth as well as briefly describing the importance of stress intensity factors in corrosion and residual stress cracking.
Download or read book Stress Analysis of Notch Problems written by George C. Sih and published by Springer. This book was released on 1978-06-30 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: The magnification of stresses at geometric stress concentrations is of great importance in engineering design. In particular, problems of frac ture are all the result of local concentrations of stresses arising from abrupt changes of shape or geometrical discontinuities. Typical exam ples are notches, grooves, fillets, flaws and cracks. Their shape and degree of sharpness can greatly influence the load bearing capacity of structural members. From the designer's point of view, a fracture analysis will involve two major concerns: (1) a stress analysis of the geometrical disturbance, and (2) a postulate predicting the event of fracture itself. Comprehensive treatments of the elastic stress dis tributions around a wide variety of geometric cavities are available in the open literature and will not be repeated in this volume. The number of proposed failure criteria is equally exhaustive. However, there is still no coherent treatment of failure for all geometric cavities regardless of their shapes and sizes. This fifth volume of the series on Mechanics of Fracture attempts to join the behavior of sharp discontinuities such as cracks to that of notches or cavities and to provide a few typical analytical methods of stress solutions. The finite element method has been purposely left out, for it is now becoming common procedure in cases too complex for analysis. One of the major applications for fracture mechanics analyses is an assessment of the influence of defects on the strength of structural components.
Download or read book Fracture and Size Effect in Concrete and Other Quasibrittle Materials written by Zdenek P. Bazant and published by Routledge. This book was released on 2019-03-04 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fracture and Size Effect in Concrete and Other Quasibrittle Materials is the first in-depth text on the application of fracture mechanics to the analysis of failure in concrete structures. The book synthesizes a vast number of recent research results in the literature to provide a comprehensive treatment of the topic that does not give merely the facts - it provides true understanding. The many recent results on quasibrittle fracture and size effect, which were scattered throughout many periodicals, are compiled here in a single volume. This book presents a well-rounded discussion of the theory of size effect and scaling of failure loads in structures. The size effect, which is the most important practical manifestation of fracture behavior, has become a hot topic. It has gained prominence in current research on concrete and quasibrittle materials. The treatment of every subject in Fracture and Size Effect in Concrete and Other Quasibrittle Materials proceeds from simple to complex, from specialized to general, and is as concise as possible using the simplest level of mathematics necessary to treat the subject clearly and accurately. Whether you are an engineering student or a practicing engineer, this book provides you with a clear presentation, including full derivations and examples, from which you can gain real understanding of fracture and size effect in concrete and other quasibrittle materials.
Download or read book The Boundary Element Method Volume 2 written by M. H. Aliabadi and published by John Wiley & Sons. This book was released on 2002-04-29 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt: The boundary element method (BEM) is a modern numerical technique, which has enjoyed increasing popularity over the last two decades, and is now an established alternative to traditional computational methods of engineering analysis. The main advantage of the BEM is its unique ability to provide a complete solution in terms of boundary values only, with substantial savings in modelling effort. This two-volume book set is designed to provide the readers with a comprehensive and up-to-date account of the boundary element method and its application to solving engineering problems. Each volume is a self-contained book including a substantial amount of material not previously covered by other text books on the subject. Volume 1 covers applications to heat transfer, acoustics, electrochemistry and fluid mechanics problems, while volume 2 concentrates on solids and structures, describing applications to elasticity, plasticity, elastodynamics, fracture mechanics and contact analysis. The early chapters are designed as a teaching text for final year undergraduate courses. Both volumes reflect the experience of the authors over a period of more than twenty years of boundary element research. This volume, Applications in Solids and Structures, provides a comprehensive presentation of the BEM from fundamentals to advanced engineering applications and encompasses: Elasticity for 2D, 3D and Plates and Shells Non-linear, Transient and Thermal Stress Analysis Crack Growth and Multi-body Contact Mechanics Sensitivity Analysis and Optimisation Analysis of Assembled Structures. An important feature of this book is the in-depth presentation of BEM formulations in all the above fields, including detailed discussions of the basic theory, numerical algorithms and where possible simple examples are included, as well as test results for practical engineering applications of the method. Although most of the methods presented are the latest developments in the field, the author has included some simple techniques, which are helpful in understanding the computer implementation of BEM. Another notable feature is the comprehensive presentation of a new generation of boundary elements known as the Dual Boundary Element Method. Written by an internationally recognised authority in the field, this is essential reading for postgraduates, researchers and practitioners in Aerospace, Mechanical and Civil Engineering and Applied Mathematics.
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1979 with total page 840 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Mechanics 95 written by S.N. Atluri and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 3181 pages. Available in PDF, EPUB and Kindle. Book excerpt: AI!, in the earlier conferences (Tokyo, 1986; Atlanta, 1988, Melbourne, 1991; and Hong Kong, 1992) the response to the call for presentations at ICES-95 in Hawaii has been overwhelming. A very careful screening of the extended abstracts resulted in about 500 paper being accepted for presentation. Out of these, written versions of about 480 papers reached the conference secretariat in Atlanta in time for inclusion in these proceedings. The topics covered at ICES-95 range over the broadest spectrum of computational engineering science. The editors thank the international scientific committee, for their advice and encouragement in making ICES-95 a successful scientific event. Special thanks are expressed to the International Association for Boundary Elements Methods for hosting IABEM-95 in conjunction with ICES-95. The editors here express their deepest gratitude to Ms. Stacy Morgan for her careful handling of a myriad of details of ICES-95, often times under severe time constraints. The editors hope that the readers of this proceedings will find a kaleidoscopic view of computational engineering in the year 1995, as practiced in various parts of the world. Satya N. Atluri Atlanta, Georgia, USA Genki Yagawa Tokyo,Japan Thomas A. Cruse Nashville, TN, USA Organizing Committee Professor Genki Yagawa, University of Tokyo, Japan, Chair Professor Satya Atluri, Georgia Institute of Technology, U.S.A.
Download or read book Fracture Mechanics written by Nicholas Perrone and published by . This book was released on 1978 with total page 744 pages. Available in PDF, EPUB and Kindle. Book excerpt:
