Cleavage Fracture

In this book the authors focus on the description of the physical nature of cleavage fracture to offer scientists, engineers and students a comprehensive physical model which vividly describes the cleavage microcracking processes operating on the local (microscopic) scale ahead of a defect. The descriptions of the critical event and the criteria for cleavage fracture will instruct readers in how to control the cleavage processes and optimize microstructure to improve fracture toughness of metallic materials. Physical (mechanical) processes of cleavage fracture operating on the local (microscopic) scale, with the focus on the crack nucleation and crack propagation across the particle/grain and grain/grain boundaries Critical event, i.e., the stage of greatest difficulty in forming the microcrack, which controls the cleavage fracture Criteria triggering the cleavage microcracking with incorporation of the actions of macroscopic loading environment into the physical model Effects of microstructure on the cleavage fracture, including the effects of grain size, second phase particles and boundary Comprehensive description of the brittle fracture emerging in TiAl alloys and TiNi memory alloys

Fracture mechanics is an essential tool for engineers in a number of different engineering disciplines. For example, an engineer in a metals- or plastics-dependent industry might use fracture mechanics to evaluate and characterize materials, while another in aerospace or construction might use fracture mechanics-based methods for product design and service life-time estimation. This balanced treatment, which covers both applied engineering and mathematical aspects of the topic, provides a much-needed multidisciplinary treatment of the field suitable for the many diverse applications of the subject. While texts on linear elastic fracture mechanics abound, no complete treatments of the complex topic of nonlinear fracture mechanics have been available in a textbook format - until now. Written by an author with extensive industry credentials as well as academic experience, Nonlinear Fracture Mechanics for Engineers examines nonlinear fracture mechanics and its applications in mechanics, materials testing, and life prediction of components. The book includes the first-ever complete examination of creep and creep-fatigue crack growth. Examples and problems reinforce the concepts presented. A complete chapter on applications and case studies involving nonlinear fracture mechanics completes this thorough evaluation of this dynamic field of study.

The 16th European Conference of Fracture (ECF16) was held in Greece, July, 2006. It focused on all aspects of structural integrity with the objective of improving the safety and performance of engineering structures, components, systems and their associated materials. Emphasis was given to the failure of nanostructured materials and nanostructures including micro- and nano-electromechanical systems (MEMS and NEMS).

When asked to start teaching a course on engineering fracture mechanics, I realized that a concise textbook, giving a general oversight of the field, did not exist. The explanation is undoubtedly that the subject is still in a stage of early development, and that the methodologies have still a very limited applicability. It is not possible to give rules for general application of fracture mechanics concepts. Yet our comprehension of cracking and fracture beha viour of materials and structures is steadily increasing. Further developments may be expected in the not too distant future, enabling useful prediction of fracture safety and fracture characteristics on the basis of advanced fracture mechanics procedures. The user of such advanced procedures m\lst have a general understanding of the elementary concepts, which are provided by this volume. Emphasis was placed on the practical application of fracture mechanics, but it was aimed to treat the subject in a way that may interest both metallurgists and engineers. For the latter, some general knowledge of fracture mechanisms and fracture criteria is indispensable for an apprecia tion of the limita tions of fracture mechanics. Therefore a general discussion is provided on fracture mechanisms, fracture criteria, and other metal lurgical aspects, without going into much detail. Numerous references are provided to enable a more detailed study of these subjects which are still in a stage of speculative treatment.

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.

Improving the structural integrity together with the performance (weight, time to failure,...) of structures requires a persisting effort in the field of mechanics of materials and structures. This can be achieved by a better understanding of the relationships between microscopic mechanisms and the macroscopic material behavior and structural response with respect to damage and fracture. This improvement strategy of materials, structures and assement methods can be described as local approach to fracture. The local approach to fracture is an active research field. Initially developped in the context of steel structures (pressure vessels), its application domain has become wider and now deals with various kinds of materials (metallic alloys, metal matrix composites, polymers, elastomers, concrete) as well as various physical deformation and damage mechanisms (plasticity, creep, fatigue, ductile fracture, brittle fracture, ...). This volume contains the proceedings on an international conference dedicated to these issues.