The mechanical behaviour of Earth’s curst with a self-similar structure of faults is modelled using a continuous sequence of continua each with its own size of the averaging volume element. The overall tensorial properties scale isotropically, i.e. according to a power law with common exponent. In fault systems modelled by sets of 2-D cracks, the scaling is isotropic for both isotropically orie...

In this paper, a series of studies to reinforced concrete cracks have been done by image graying, calibrating, image denoising, image enhancement and image segmentation, and the binary image of cracks is finally obtained. Using the Box Method, the fractal dimension of cracks is determined. The relationships between the fractal dimension of surface cracks in the cracking beam under three-point l...

Lacquer cracks are thought to represent healed mechanical breaks in the retinal pigment epithelium, Bruch's membrane, and choriocapillaris complex. In this study, we analyzed the indocyanine green (ICG) angiographic features of lacquer cracks and compared them with findings using fluorescein angiography. Complete ophthalmologic examinations, fluorescein angiography, and ICG angiography were per...

This paper deals with the basic mechanisms of fatigue damage in materials exposed to service and a series of nondestructive techniques for the early detection of this damage. For all materials with reasonably high fracture toughness it is the organized motion of dislocations that either forms extrusions/intrusions (surface roughness) or the piling up of dislocations at grain boundaries or inter...

Advanced artificial flaw manufacturing method has become available. The method produces true fatigue cracks, which are representative of most service-induced cracks. These cracks can be used to simulate behaviour of realistic cracks under service conditions. This paper introduces studies of the effects of different thermal loading cycles to crack opening and residual stress state as seen at the...

Polydimethyldisiloxane (PDMS) substrates were coated with thin layers of gold varying in thickness between 40 nm and 160 nm. Arrays of parallel cracks formed when a tensile strain was applied to the coated system, with the spacing between the cracks being approximately inversely proportional to the strain. When the crack profiles were examined, it was noted that the cracks extended deep into th...

AbstracbThe results of an experimental investigation of thermally induced parallel edge cracks in a half-plane consisting of brittle material are reported. A free edge of a glass plate heated to a uniform temperature, was brought in contact with a liquid bath cooled by dry ice. The thermal contraction of the boundary layer produced interacting tension cracks. When no initial cracks existed, a l...

When a rigid cone is slowly pushed through a thin elastic sheet, the material breaks, exhibiting a network of cracks expanding in the radial direction. Experiments conducted with aluminum sheets show that the number of cracks is selected at the beginning of the perforation process and then remains stable. A simple model predicts the number of cracks as the result of a competition between the el...

Based on the kinematic approach of limit analysis, a full set of upper bound solutions for the stability of homogeneous rock slopes subjected to tension cracks are obtained. The generalized Hoek-Brown failure criterion is employed to describe the non-linear strength envelope of rocks. In this paper, critical failure mechanisms are determined for cracks of known depth but unspecified location, c...