Subsurface mesoscale cracks exist widely in the outer ring of full ceramic ball bearings (FCBBs), which is a potential threat for stable operation related devices such as aero engines, food processing machinery, and artificial replacement hip joints. This paper establishes dynamic model subsurface FCBBs based on strain energy theory, influence different crack lengths running state analyzed. The...

A premature failure mode in steel rolling element bearings called white structure flaking (WSF) occurs in wind turbine gearbox bearings. WSF can occur in as little as 6-24 months of operation. WSF is associated with microstructural alterations called white etching area (WEA) and white etching cracks (WECs) that form in the ~1 mm zone beneath the contact surface. The tribological drivers for WSF...

Grinding and polishing are widely used surface finish operations for a variety of precision and delicate component of ceramics, such as silicon wafers and gauges. However, the formation and evaluation of the subsurface damage induced have not been investigated, although subsurface damage is extremely important to the quality of the products. Grinding and polishing are usually carried out by a s...

In 2004, a team comprised of researchers and service providers launched the Safer Crack Use, Outreach, Research and Education (SCORE) project in the Downtown Eastside of Vancouver, British Columbia, Canada. The project was aimed at developing a better understanding of the harms associated with crack cocaine smoking and determining the feasibility of introducing specific harm reduction strategie...

Abstract: Rotating bending fatigue tests have been performed using smooth specimens of a rolled AZ31 magnesium alloy in laboratory air at ambient temperature. Fatigue strength and characteristic was evaluated and fracture mechanism was discussed on the basis fracture surface analysis. Electrical polishing (EP) as well as deep rolling (ball burnishing (BB)) U-notched specimens were performed on ...

Observations of natural fractures in core or image logs typically give limited information on orientation, aperture and intensity. Because of the sparseness of wellbore intersections of fractures, data analysis results in incomplete statistical characterization of the fracture population, leaving interwell characterization almost impossible. Using basic fracture mechanics models and a novel cor...

This paper presents a modeling approach for studying hydro-mechanical coupled processes, including fracture development, within geological formations. This is accomplished through the novel linking of two codes: TOUGH2, which is a widely used simulator of subsurface multiphase flow based on the finite volume method; and an implementation of the Rigid-BodySpring Network (RBSN) method, which prov...