Journal ArticleDOI
Family of crack-tip fields characterized by a triaxiality parameter—II. Fracture applications
Noel P. O’Dowd,C. F. Shih +1 more
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In this paper, the J-dominance is used to define the size scale over which large stresses and strains develop while Q scales the near-tip stress distribution and the stress triaxiality achieved ahead of the crack.Abstract:
C entral to the J-based fracture mechanics approach is the concept of J-dominance whereby J alone sets the stress level as well as the size scale of the zone of high stresses and strains. In Part I the idea of a J Q annulus was developed. Within the annulus, the plane strain plastic near-tip fields are members of a family of solutions parameterized by Q when distances are normalized by J σ 0 , where σ0is the yield stress, J and Q have distinct roles: J sets the size scale over which large stresses and strains develop while Q scales the near-tip stress distribution and the stress triaxiality achieved ahead of the crack. Specifically, negative (positive) Q values mean that the hydrostatic stress is reduced (increased) by Qσ0 from the Q = 0 plane strain reference state. Therefore Q provides a quantitative measure of crack-tip constraint, a term widely used in the literature concerning geometry and size effects on a material's resistance to fracture. These developments are discussed further in this paper. It is shown that the J Q approach considerably extends the range of applicability of fracture mechanics for shallow-crack geometries loaded in tension and bending, and deep-crack geometries loaded in tension. The J Q theory provides a framework to organize toughness data as a function of constraint and to utilize such data in engineering applications. Two methods for estimating Q at fully yielded conditions and an interpolation scheme are discussed. The effects of crack size and specimen type on fracture toughness are addressed.read more
Citations
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Journal ArticleDOI
A review of fracture toughness transferability with constraint and stress gradient
TL;DR: In this article, only constraint and stress gradient approaches to transferability of fracture toughness are examined, and different constraint parameters are defined and discussed, and one example is given in each case. And the uses of plasticity with gradient and the relative stress gradient in local fracture approaches are also examined.
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A Generalized Interaction Integral Method for the Evaluation of the T-Stress in Orthotropic Functionally Graded Materials Under Thermal Loading
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TL;DR: In this article, the interaction integral method was used to evaluate the nonsingular T-stress as well as mixed-mode stress intensity factors in orthotropic functionally graded materials under thermomechanical loads.
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Application of coupled brittle–ductile model to study correlation between Charpy energy and fracture toughness values
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References
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Journal ArticleDOI
A Path Independent Integral and the Approximate Analysis of Strain Concentration by Notches and Cracks
TL;DR: In this paper, an integral is exhibited which has the same value for all paths surrounding a class of notches in two-dimensional deformation fields of linear or non-linear elastic materials.
Journal ArticleDOI
Plane strain deformation near a crack tip in a power-law hardening material
James R. Rice,G. F. Rosengren +1 more
TL;DR: In this paper, the authors investigated the C rack-tip strain singularities with the aid of an energy line integral exhibiting path independence for all contours surrounding a crack tip in a two-dimensional deformation field of an elastic material (or elastic/plastic material treated by a deformation theory).
Journal ArticleDOI
Singular behaviour at the end of a tensile crack in a hardening material
TL;DR: In this paper, a total deformation theory of plasticity, in conjunction with two hardening stress-strain relations, is used to determine the dominant singularity at the tip of a crack in a tension field.
Journal ArticleDOI
On the relationship between critical tensile stress and fracture toughness in mild steel
TL;DR: In this paper, the critical value of tensile stress (a) for unstable cleavage fracture to the fracture toughness (K,,) for a high-nitrogen mild steel under plane strain conditions.
Journal ArticleDOI
Family of crack-tip fields characterized by a triaxiality parameter—I. Structure of fields
Noel P. O’Dowd,C. F. Shih +1 more
TL;DR: In this article, a two-parameter fracture mechanics approach for tensile mode crack tip states in which the fracture toughness and the resistance curve depend on Q, i.e., JC(Q) and JR(Δa, Q), is proposed.
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