Toughening Mechanisms in Quasi-Brittle Materials
Toughening Mechanisms in Quasi-Brittle Materials

Author: S.P. Shah

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 590

ISBN-13: 9401133883

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A variety of ceramic materials has been recently shown to exhibit nonlinear stress strain behavior. These materials include transformation-toughened zirconia which undergoes a stress-induced crystallographic transformation in the vicinity of a propagating crack, microcracking ceramics, and ceramic-fiber reinforced ceramic matrices. Since many of these materials are under consideration for structural applications, understanding fracture in these quasi-brittle materials is essential. Portland cement concrete is a relatively brittle material. As a result mechanical behavior of concrete, conventionally reinforced concrete, prestressed concrete and fiber reinforced concrete is critically influenced by crack propagation. Crack propagation in concrete is characterized by a fracture process zone, microcracking, and aggregate bridging. Such phenomena give concrete toughening mechanisms, and as a result, the macroscopic response of concrete can be characterized as that of a quasi-brittle material. To design super high performance cement composites, it is essential to understand the complex fracture processes in concrete. A wide range of concern in design involves fracture in rock masses and rock structures. For example, prediction of the extension or initiation of fracture is important in: 1) the design of caverns (such as underground nuclear waste isolation) subjected to earthquake shaking or explosions, 2) the production of geothermal and petroleum energy, and 3) predicting and monitoring earthquakes. Depending upon the grain size and mineralogical composition, rock may also exhibit characteristics of quasi-brittle materials.

Workshop Proceedings: Toughening Mechanisms in Quasi-Brittle Materials Held on 16-20 July 1990 in Evanston, Illinois
Workshop Proceedings: Toughening Mechanisms in Quasi-Brittle Materials Held on 16-20 July 1990 in Evanston, Illinois

Author:

Publisher:

Published: 1991

Total Pages: 590

ISBN-13:

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Recently, considerable interest has been developing in understanding and modeling the fracture processes in these quasi-brittle materials as well as in designing materials with improved toughness. The research activities in these groups of materials: ceramics, cement and rock can be substantially enhanced with the exchange of information between these three groups of investigators. Since the field is relatively new, it is likely that the researchers working with one set of materials are not aware of similar developments with other set of materials. Although each material has its own set of specific characteristics, many common aspects can be shared among these quasi-brittle materials. These include: (1) application of nonlinear fracture mechanics, (2) experimental and theoretical considerations of strain localization, (3) microscopic observation of fracture process zone, (4) nondestructive evaluation of damage, (5) models to relate microstructure with macroscopic response, and (6) development of experimental and theoretical tools. The purpose of this workshop was to bring together researchers addressing the problem of fracture in cement, ceramics, and rock so that they can share their knowledge and develop a more general syntheses of the problem.

NATO Advanced Research Workshop. Toughening Mechanisms in Quasi-Brittle Materials, Held in Evanston, Illinois on July 16-20, 1990
NATO Advanced Research Workshop. Toughening Mechanisms in Quasi-Brittle Materials, Held in Evanston, Illinois on July 16-20, 1990

Author: Surendra P. Shah

Publisher:

Published: 1990

Total Pages: 624

ISBN-13:

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This workshop brought together researchers addressing the problem of fracture in cement, ceramics, and rock so that they could share their knowledge and develop a more general syntheses of the problem. This preprint volume contains contributions from lectures for each of the 9 sessions. The final proceedings of this workshop will be published in a hardcover book by Kluewer Academic Publishers (NATO ASI Series). This book will contain 36 chapters; the finalized contributions of 27 lectures and 9 reporters. Keywords: Quasi brittle materials, Toughening mechanisms in materials, Workshop, Cement fracture, Ceramic fracture, Rock fracture. (js).

Crack Deflection Toughening Mechanism in Brittle Materials
Crack Deflection Toughening Mechanism in Brittle Materials

Author: T. Ohashi

Publisher:

Published: 2002

Total Pages: 15

ISBN-13:

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Toughening mechanisms in polycrystalline ceramics and ceramic-based composites were discussed based on Griffith's energy equilibrium and classified into three groups: (A) the frontal process-zone toughening mechanism, (B) the crack-bridging mechanism, and (C) the macroscopic crack-deflection mechanism. The increase in fracture toughness caused by enforced macroscopic crack-deflection was estimated using the energy equilibrium between the energy-release rate and the fracture-energy rate. The analytical results revealed that the fracture toughness under Mode I loading was enhanced by twice the normal value when the crack propagates in the direction 90° from its original plane. Under Mode II loading the fracture toughness is increased 1.2 times the normal value when the crack propagates in its original plane. Crack-deflection tests were carried out by using wooden, thin rectangular plates with a central crack. The increase in the fracture toughness caused by crack deflection was confirmed and the experimental data was coincident with the calculated results.

Fracture of Brittle Disordered Materials: Concrete, Rock and Ceramics
Fracture of Brittle Disordered Materials: Concrete, Rock and Ceramics

Author: G. Baker

Publisher: CRC Press

Published: 2004-01-14

Total Pages: 593

ISBN-13: 0203223454

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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.

Fracture Mechanics of Ceramics
Fracture Mechanics of Ceramics

Author: R.C. Bradt

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 592

ISBN-13: 1461533503

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These volumes, 9 and 10, of Fracture Mechanics of Ceramics constitute the proceedings of an international symposium on the fracture mechanics of ceramic materials held at the Japan Fine Ceramics Center, Nagoya, Japan on July 15, 16, 17, 1991. These proceedings constitute the fifth pair of volumes of a continuing series of conferences. Volumes 1 and 2 were from the 1973 symposium, volumes 3 and 4 from a 1977 symposium, and volumes 5 and 6 from a 1981 symposium all of which were held at The Pennsylvania State University. Volumes 7 and 8 are from the 1985 symposium which was held at the Virginia Polytechnic Institute and State University. The theme ofthis conference, as for the previous four, focused on the mechanical behavior ofceramic materials in terms of the characteristics of cracks, particularly the roles which they assume in the fracture processes and mechanisms. The 82 contributed papers by over 150 authors and co-authors represent the current state of that field. They address many of the theoretical and practical problems ofinterest to those scientists and engineers concerned with brittle fracture.

Fracture and Size Effect in Concrete and Other Quasibrittle Materials
Fracture and Size Effect in Concrete and Other Quasibrittle Materials

Author: Zdenek P. Bazant

Publisher: Routledge

Published: 2019-03-04

Total Pages: 648

ISBN-13: 1351447289

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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.