The growth of slant cracks by fretting fatigue of a half plane in contact with a flat rounded pad was studied. The mode I and mode II stress intensity factors for cracks of various lengths and directions were calculated using the semi-analytical method of the distribution of dislocations, and their cumulative effect on the crack growth was investigated using the strain energy density criterion....

when the degree of saturation at intersection approaches one, webster’s optimum cycle length equation becomes inapplicable, because the cycle length will becomes very big when the degree of saturation approaches one and will be fully unrealistic when the degree of saturation becomes greater than one. this is not a problem for hcm2000 method. but optimum cycle length calculation in this method h...

Hip fractures are an important socio-economic problem in western countries. Over the past 60 years orthogeriatric care has improved management of older patients admitted to hospital after suffering hip fractures. Quality co-management units increased, reducing adverse events during acute admission, length stay, both in-hospital and mid-term mortality, as well healthcare social costs. Neverthele...

Existing fractured gas reservoir development techniques are mainly based on dual medium numerical-simulation models, which can, to a certain extent, effectively simulate natural fractures with high fracture density; however, these models have some limitations, particularly in terms of simulating the morphology and distribution. Considering carbonate reservoirs complex fractures, this paper, we ...

This study investigates propagation of mode I crack in B70 pre-stressed concrete sleepers by fracture mechanics approach. A new experimental analysis is done for notched B70 pre-stressed concrete sleepers with Replica test and image analysis. A scanning electron microscope test (SEM) and an image analysis are applied for the Replica test in order to determine crack length and crack mouth openin...

Fracture mechanics is a field of solid mechanics interested with the behaviour of materials under certain loads their distribution and finally the fracture criteria of given materials.This Paper evaluates size dependency of fracture parameters, fracture energy (Gf) and fracture process zone effective length (Cf) of concrete concluded as per Bazant’s size effect method. Fracture mechanics standa...

It is known that the single-modal Weibull model describes well the size effect of brittle fiber tensile strength. However, some ceramic fibers have been reported that single-modal Weibull model provided biased estimation on the gauge length dependence. A hypothesis on the bias is that the density of critical defects is very small, thus, fracture probability of small gauge length samples distrib...

Conductivity optimization is important for hydraulic fracturing due to its key roles in determining fractured well productivity. Proppant embedment is an important mechanism that could cause a remarkable reduction in fracture width and, thus, damage the fracture conductivity. In this work a new analytical model, based on contact mechanics and the Carman–Kozeny model, is developed to calculate t...

Despite the significant advancements in geomodelling techniques over past few decades, it is still quite challenging to obtain accurate assessments of hydraulic fracture propagation. This work investigates effect fluid leak-off a dual-porosity system on propagation geometry, which, turn, affects hydrocarbon recovery from tight and unconventional reservoirs. Fracture within reservoirs was analyz...