Journal ArticleDOI
Toughening of Ceramics through Crack Bridging by Ductile Particles
Fazil Erdogan,Paul F. Joseph +1 more
TLDR
In this paper, the fracture problem for a brittle matrix reinforced by ductile particles is considered, and the authors show that the crack surface bridging forces provided by the unbroken particles improve the fracture toughness of the matrix.Abstract:
The fracture problem for a brittle matrix reinforced by ductile particles is considered. In the usual manner it is assumed that the crack surface bridging forces provided by the unbroken particles improve the fracture toughness of the matrix. Depending on the relative strength of the interfacial bonding between the matrix and the particles, two particle force models are introduced, namely, a force that is independent of the crack opening displacement (δ) and a force that is a highly non-linear function of δ. The problem is studied for a penny-shaped or plane strain crack in an infinite medium and for a surface crack in a semi-infinite medium under plane strain conditions. The toughness improvement in the matrix is shown to depend on a dimensionless bimaterial constant representing the inherent toughness of the matrix and the yield behavior of the particles. The effective toughness of the composite medium is calculated as a function of the crack size and the bimaterial constant.read more
Citations
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On the solution of integral equations with strong ly singular kernels
A. C. Kaya,F. Erdogan +1 more
TL;DR: In this paper, some useful formulas are developed to evaluate integrals having a singularity of the form (t-x) sup-m, m, m or = 1.
Journal ArticleDOI
Strengthening and Toughening Mechanisms of Ceramic Nanocomposites
TL;DR: In this article, small, brittle particulate inclusions have been shown to cause crack-tip bridging at short distances behind the crack tip, and it is the latter that produces the very high fracture strength of the ceramic nanocomposite.
Journal ArticleDOI
Concepts for bridged cracks in fracture and fatigue
Brian N. Cox,David B. Marshall +1 more
TL;DR: In this paper, the role of length scales in determining ductility, notch sensitivity, and whether failure is catastrophic or noncatastrophic is discussed, as well as the roles of length scale in determining notch sensitivity and ductility.
Journal ArticleDOI
Size Effect in Fracture of Ceramics and Its Use To Determine Fracture Energy and Effective Process Zone Length
Zdenek P. Bazant,Mohammad Kazemi +1 more
TL;DR: In this article, a size effect law was used to identify nonlinear fracture properties from measured maximum loads of geometrically similar fracture specimens of sufficiently different sizes. But the authors did not consider the effect of the type of the toughening mechanism in the fracture process zone.
Journal ArticleDOI
Stable and unstable solutions for bridged cracks in various specimens
Brian N. Cox,David B. Marshall +1 more
TL;DR: In this article, the authors formulated the problem of bridged cracks as an integral equation, and provided a self-consistent solution for the problem when the bridging tractions, p, are a function of crack opening displacement, rather than an explicit function of position in the crack.
References
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Journal ArticleDOI
Matrix fracture in fiber-reinforced ceramics
TL;DR: In this paper, the critical conditions for the onset of widespread matrix cracking are studied analytically on the basis of fracture mechanics theory, and theoretical results are compared with experimental data for a SiC fiber, lithium-alumina-silicate glass matrix composite.
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The mechanics of matrix cracking in brittle-matrix fiber composites
TL;DR: In this paper, the authors evaluated the stress for matrix cracking in brittle-matrix fiber composites using a stress intensity approach, in which the influence of the fibers that bridge the matrix crack is represented by closure tractions at the crack surfaces.
Journal ArticleDOI
Mechanics of Transformation‐Toughening in Brittle Materials
TL;DR: In this article, it is shown that the initial zone, prior to crack growth, provides no change in stress intensity. As the crack grows, the zone associated with a positive transformation strain induces a stress-intensity reduction that rises to a maximum level after some crack propagation.
Journal ArticleDOI
Overview no. 48
TL;DR: In this article, a comprehensive review of toughness mechanisms in transformable brittle solids is presented, with primary emphasis on transformation toughening, although micro-cracks and deflection tougheng are also considered.
Journal ArticleDOI
Continuum theory of dilatant transformation toughening in ceramics
TL;DR: In this paper, a continuum description is introduced for an elastic solid which contains particles that undergo an irreversible stress-induced dilatant transformation, and the behaviors of the composite solid considered range from abrupt complete transformation at a critical mean stress to strain controlled transformation at constant stress.