Constraint Effects in Fracture


Book Description

Papers presented at the symposium on [title] held in Indianapolis, Indiana, May 1991, provide a framework for quantifying constraint effects in terms of both continuum mechanics and micro-mechanical modeling approaches. Such a framework is useful in establishing accurate predictions of the fracture







Fracture and Fatigue Emanating from Stress Concentrators


Book Description

A vast majority of failures emanate from stress concentrators such as geometrical discontinuities. The role of stress concentration was first highlighted by Inglis (1912) who gives a stress concentration factor for an elliptical defect, and later by Neuber (1936). With the progress in computing, it is now possible to compute the real stress distribution at a notch tip. This distribution is not simple, but looks like pseudo-singularity as in principle the power dependence with distance remains. This distribution is governed by the notch stress intensity factor which is the basis of Notch Fracture Mechanics. Notch Fracture Mechanics is associated with the volumetric method which postulates that fracture requires a physical volume. Since fatigue also needs a physical process volume, Notch Fracture Mechanics can easily be extended to fatigue emanating from a stress concentration.




Topics in Fracture and Fatigue


Book Description

Fracture in structural materials remains a vital consideration in engineering systems, affecting the reliability of machines throughout their lives. Impressive advances in both the theoretical understanding of fracture mechanisms and practical developments that offer possibilities of control have re-shaped the subject over the past four decades. The contributors to this volume, including some of the most prominent researchers in the field, give their long-range perspectives of the research on the fracture of solids and its achievements. The subjects covered in this volume include: statistics of brittle fracture, transition of fracture from brittle to ductile, mechanics and mechanisms of ductile separation of heterogenous solids, the crack tip environment in ductile fracture, and mechanisms and mechanics of fatigue. Materials considered range from the usual structural solids to composites. The chapters include both theoretical points of view and discussions of key experiments. Contributors include: from MIT, A.S. Argon, D.M. Parks; from Cambridge, M.F. Ashby; from U.C. Santa Barbara, A.G. Evans, R. McMeeking; from Glasgow, J. Hancock; from Harvard, J.W. Hutchinson, J.R. Rice; from Sheffield, K.J. Miller; from Brown, A. Needleman; from the Ecole des Mines, A. Pineau; from U.C. Berkeley, R. O. Ritchie; and from Copenhagen, V. Tvergaard.




Advanced Fracture Mechanics and Structural Integrity


Book Description

Advanced Fracture Mechanics and Structural Integrity is organized to cover quantitative descriptions of crack growth and fracture phenomena. The mechanics of fracture are explained, emphasizing elastic-plastic and time-dependent fracture mechanics. Applications are presented, using examples from power generation, aerospace, marine, and chemical industries, with focus on predicting the remaining life of structural components and advanced testing metods for structural materials. Numerous examples and end-of-chapter problems are provided, along with references to encourage further study.The book is written for use in an advanced graduate course on fracture mechanics or structural integrity.




Nanosensors for Smart Manufacturing


Book Description

Nanosensors for Smart Manufacturing provides information on the fundamental design concepts and emerging applications of nanosensors in smart manufacturing processes. In smart production, if the products and machines are integrated, embedded, or equipped with sensors, the system can immediately collect the current operating parameters, predict the product quality, and then feed back the optimal parameters to machines in the production line. In this regard, smart sensors and their wireless networks are important components of smart manufacturing. Nanomaterials-based sensors (nanosensors) offer several advantages over their microscale counterparts, including lower power consumption, fast response time, high sensitivity, lower concentration of analytes, and smaller interaction distance between sensors and products. With the support of artificial intelligence (AI) tools such as fuzzy logic, genetic algorithms, neural networks, and ambient intelligence, sensor systems have become smarter. This is an important reference source for materials scientists and engineers who want to learn more about how nanoscale sensors can enhance smart manufacturing techniques and processes. - Outlines the smart nanosensor classes used in manufacturing applications - Shows how nanosensors are being used to make more efficient manufacturing systems - Assesses the major obstacles to designing nanosensor-based manufacturing systems at an industrial scale




Rock Fractures and Fluid Flow


Book Description

Scientific understanding of fluid flow in rock fractures--a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storage--has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.




Fracture and Fatigue of Welded Joints and Structures


Book Description

The failure of any welded joint is at best inconvenient and at worst can lead to catastrophic accidents. Fracture and fatigue of welded joints and structures analyses the processes and causes of fracture and fatigue, focusing on how the failure of welded joints and structures can be predicted and minimised in the design process.Part one concentrates on analysing fracture of welded joints and structures, with chapters on constraint-based fracture mechanics for predicting joint failure, fracture assessment methods and the use of fracture mechanics in the fatigue analysis of welded joints. In part two, the emphasis shifts to fatigue, and chapters focus on a variety of aspects of fatigue analysis including assessment of local stresses in welded joints, fatigue design rules for welded structures, k-nodes for offshore structures and modelling residual stresses in predicting the service life of structures.With its distinguished editor and international team of contributors, Fracture and fatigue of welded joints and structures is an essential reference for mechanical, structural and welding engineers, as well as those in the academic sector with a research interest in the field. - Analyses the processes and causes of fracture and fatigue, focusing predicting and minimising the failure of welded joints in the design process - Assesses the fracture of welded joints and structure featuring constraint-based fracture mechanics for predicting joint failure - Explores specific considerations in fatigue analysis including the assessment of local stresses in welded joints and fatigue design rules for welded structures




Nanomaterials from Clay Minerals


Book Description

Nanomaterials from Clay Minerals: A New Approach to Green Functional Materials details the structure, properties and modification of natural nanoscale clay minerals and their application as the green constituent of functional materials. Natural nanomaterials from clay minerals have diverse morphologies, from 1D to 3D, including nanorods, nanofibers, nanotubes, nanosheets and nanopores. These structures show excellent adsorption, reinforcing, supporter, electronic, catalytic and biocompatible properties and are great as sustainable alternatives for toxic or expensive artificial materials. This book provides systematic coverage of clay nanomaterials as eco-friendly resources, emphasizing the importance of such materials in a range of industries, including biomedicine, energy and electronics. This book will provide an important reference for materials scientists and engineers who have an interest in sustainable material development. - Presents systematic coverage of a broad range of nanomaterials from clay minerals, including Kaolinite, Smectite and Halloysite - Depicts use cases for each mineral in a variety of applications, such as drug delivery, agriculture, and in the reinforcement of polymer materials - Provides an overview on the advantages and limitations of nanomaterials from clay minerals, as well as chapters on the future potential of such materials




Quasibrittle Fracture Mechanics and Size Effect


Book Description

Many modern engineering structures are composed of brittle heterogenous, or quasibrittle, materials. These include concrete, composites, tough ceramics, rocks, cold asphalt mixtures, and many brittle materials at the microscale. Understanding the failure behavior of these materials is of paramount importance for improving the resilience and sustainability of various engineering structures including civil infrastructure, aircraft, ships, military armors, and microelectronic devices. Designed for graduate and upper-level undergraduate university courses, this textbook provides a comprehensive treatment of quasibrittle fracture mechanics. It includes a concise but rigorous examination of linear elastic fracture mechanics, which is the foundation of all fracture mechanics. It also covers the fundamental concepts of nonlinear fracture mechanics, and introduces more advanced concepts such as triaxial stress state in the fracture process zone, nonlocal continuum models, and discrete computational models. Finally, the book features extensive discussion of the various practical applications of quasibrittle fracture mechanics across different structures and engineering disciplines, and throughout includes exercises and problems for students to test their understanding.