Automated Control of Stable Crack Growth for R-Curve Measurements in Brittle Materials

Anisotropy of mechanical properties, fatigue and fracture resistance of precipitation hardened CuCrZr alloy ultrafine (UFG) grained by equal-channel angular pressing (ECAP) is in focus of the present communication. Fracture toughness was estimated in terms of J-integral and the fatigue crack growth rate was quantified. It was found that although the estimated JIC-value appeared lower than that reported in the literature for a reference alloy, the ductility, fracture and crack growth resistance remained satisfactory after ECAP while the tensile strength and fatigue limit improved considerably. The stable crack growth rate did not differ very much for ECAP and reference conventional CuCrZr and no remarkable anisotropy in the stable crack growth was noticed.

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Creep Crack Growth Behavior in Creep-Ductile and Creep-Brittle Materials

Handbook of Materials Behavior Models ◽

10.1016/b978-012443341-0/50067-3 ◽

2001 ◽

pp. 597-610

Author(s):

A. TOSHIMITSU YOKOBORI

Keyword(s):

Crack Growth ◽

Creep Crack Growth ◽

Brittle Materials ◽

Growth Behavior ◽

Crack Growth Behavior ◽

Creep Crack

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A macroscopic theory of microcrack growth in brittle materials

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1991.0057 ◽

1991 ◽

Vol 335 (1639) ◽

pp. 455-485 ◽

Cited By ~ 9

Keyword(s):

Crack Growth ◽

Brittle Materials ◽

Macroscopic Theory ◽

Rate Of Increase ◽

Inelastic Behaviour ◽

Constitutive Response ◽

Macroscopic Plasticity ◽

Microcrack Growth ◽

Vector Valued

This paper is concerned with the development of a macroscopic theory of crack growth in fairly brittle materials. Average characteristics of the cracks are described in terms of an additional vector-valued variable in the macroscopic theory, which is determined by an additional momentum-like balance law associated with the rate of increase of the area of the cracks and includes the effects of forces maintaining the crack growth and the inertia of microscopic particles surrounding the cracks. The basic developments represent an idealized characterization of inelastic behaviour in the presence of crack growth, which accounts for energy dissipation without explicit use of macroscopic plasticity effects. A physically plausible constraint on the rate of crack growth is adopted to simplify the theory. To ensure that the results of the theory are physically reasonable, the constitutive response of the dependent variables are significantly restricted by consideration both of the energetic effects and of the microscopic processes that give rise to crack growth. These constitutive developments are in conformity with many of the standard results and observations reported in the literature on fracture mechanics. The predictive nature of the theory is illustrated with reference to two simple examples concerning uniform extensive and compressive straining.

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