A concept of combined micro and macro fracture mechanics to brittle fracture
01 Sep 1974-International Journal of Fracture (Kluwer Academic Publishers)-Vol. 10, Iss: 3, pp 375-377
TL;DR: In this paper, a concept of combined micro and macro fracture mechanics is proposed for low-stress brittle fracture of steels, which combines both stress concentrators as cracks or notches and as dislocations.
Abstract: Real materials inevitably contain both stress concentrators as cracks or notches and as dislocations, that is, both macroscopic and microscopic one. From this viewpoint, a concept of combined micro and macro fracture mechanics is proposed for low-stress brittle fracture of steels.
TL;DR: In this paper, the fracture mechanics stress intensity, K, measured for the cleavage strength of carbon steel by Professor Yokobori and colleagues, at Tohoku University and elsewhere, is shown to follow a Hall-Petch dependence on average grain diameter, l, in accordance with the model-based relationship K = c's 1 2 [σ 0 +kl −1 2 ] for which c' is a numerical factor, 5 is the effective length of the local plastic zone associated with unstable crack growth, σ 0 is a friction stress for appropriate dislocation movement within the poly
TL;DR: Based on the fractal distribution of cracks and on the theory of the weakest link, a general statistical formula of rock strength under a complex stress state has been developed in this article, of which the influence of orientation distribution and irregularity of crack growth has been taken into account.
TL;DR: In this article, the effects of grain size and of crack-tip blunting radius on the fracture toughness of tungsten polycrystals were studied by using a combined dislocation dynamics/cohesive zone model (CZM).
TL;DR: In this article, the energy unstable and critical local stress requirements for low-stress brittle fracture of notched specimens were derived based on the combined micro-and macro fracture mechanics, that is, the two requisites necessary for the crack propagation.
TL;DR: In this paper, the effect of heat treatment and oxidation treatment on coal's mass transport ability was analyzed comprehensively with industrial analysis, infrared spectrum, and other experimental means, and the mechanism of heat and oxidation on improvement of mass transport capability in coals was analyzed.