scholarly journals BEM formulation based on dipoles of stresses applied to crack growth modelling in quasi-brittle materials

2013 ◽  
Author(s):  
H. L. Oliveira ◽  
E. D. Leonel
Keyword(s):  
Crack Growth ◽  
Brittle Materials ◽  
Growth Modelling

A macroscopic theory of microcrack growth in brittle materials

1991 ◽  
Vol 335 (1639) ◽  
pp. 455-485 ◽  
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.

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

2012 ◽  
Vol 53 (2) ◽  
pp. 163-170 ◽  
Author(s):  
H. Jelitto ◽  
F. Hackbarth ◽  
H. Özcoban ◽  
G. A. Schneider
Keyword(s):  
Crack Growth ◽  
Brittle Materials ◽  
Stable Crack Growth ◽  
Automated Control

On the effect of crack growth on the scatter of strength of brittle materials

1985 ◽  
Vol 11 (4) ◽  
pp. 134 ◽  
Author(s):  
D.P.H. Hasselman ◽  
G. Ziegler
Keyword(s):  
Crack Growth ◽  
Brittle Materials

Fatigue crack growth modelling of Fão Bridge puddle iron under variable amplitude loading

2020 ◽  
Vol 136 ◽  
pp. 105588 ◽  
Author(s):  
José Correia ◽  
Hermes Carvalho ◽  
Grzegorz Lesiuk ◽  
António Mourão ◽  
Lucas Figueiredo Grilo ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Growth Modelling ◽  
Variable Amplitude Loading ◽  
Variable Amplitude

Competing Fracture Modes in Brittle Materials Subject to Concentrated Cyclic Loading in Liquid Environments: Monoliths

2005 ◽  
Vol 20 (8) ◽  
pp. 2021-2029 ◽  
Author(s):  
Yu Zhang ◽  
Sanjit Bhowmick ◽  
Brian R. Lawn
Keyword(s):  
Cyclic Loading ◽  
Crack Growth ◽  
Driving Forces ◽  
Slow Crack Growth ◽  
Finite Thickness ◽  
Brittle Materials ◽  
Soda Lime Glass ◽  
Growth Data ◽  
Fracture Modes ◽  
Maximum Contact

The competition between fracture modes in monolithic brittle materials loaded in cyclic contact in aqueous environments with curved indenters is examined. Three main modes are identified: conventional outer cone cracks, which form outside the maximum contact; inner cone cracks, which form within the contact; and median–radial cracking, which form below the contact. Relations describing short-crack initiation and long-crack propagation stages as a function of number of cycles, based on slow crack growth within the Hertzian field, are presented. Superposed mechanical driving forces—hydraulic pumping in the case of inner cone cracks and quasiplasticity in the case of median–radials—are recognized as critically important modifying elements in the initial and intermediate crack growth. Ultimately, at large numbers of cycles, the cracks enter the far field and tend asymptotically to a simple, common relation for center-loaded pennylike configurations driven by slow crack growth. Crack growth data illustrating each mode are obtained for thick soda-lime glass plates indented with tungsten carbide spheres in cyclic loading in water, for a range of maximum contact loads and sphere radii. Generally in the glass, outer cone cracks form first but are subsequently outgrown in depth as cycling proceeds by inner cones and, especially, radial cracks. The latter two crack types are considered especially dangerous in biomechanical applications (dental crowns, hip replacements) where ceramic layers of finite thickness are used as load-bearing components. The roles of test variables (contact load, sphere radius) and material properties (hardness, modulus, toughness) in determining the relative importance of each fracture mode are discussed.

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