Fatigue and fracture mechanisms have been studied in a steel-based metal matrix composite (MMC), comprising a 316L austenitic matrix reinforced with 25 wt% particulate titanium diboride (TiB2). The fracture toughness was determined in the as-HIPped condition as being slightly below 30 MPa√m. Fatigue crack growth rates have been determined, and corrected for the effects of crack closure. The fra...

Seeking the law of through-crack in double hole shaped charge can help reveal rock failure mechanism directional controlled blasting. Using LS-DYNA numerical simulation analysis, dynamic mechanical behaviors double-hole crack development and penetration elliptical bipolar linear-shaped blasting ordinary were compared studied. The results showed that it was difficult to form a straight line thro...

The characteristic asymptotic fields at the tip of sharp, semi-infinite cracks and notches are first compared with corresponding features present in selected finite bodies (edge cracks and notches). This gives an explicit view of the gradual divergence of the semiinfinite and finite problem solutions as the observation point becomes remote from the tip. Hence, upper bounds for the local plastic...

Abstract The incremental normal compliance of a contact “irregular” (non-elliptical) shape between two elastic half spaces is considered. modeled as external crack. An approximate expression for the stress intensity factor (SIFs) around its boundary, in conjunction with Rice (1975) theorem that interrelates SIFs and crack compliances, are used to evaluate compliance. results cover broad class s...

Elastic and elastic-plastic results are obtained for a semi-infinite slanted through-crack propagating in a symmetrically loaded plate strip with the aim of providing theoretical background to commonly observed plate tearing behavior. Were it is not for the slant of the crack through the thickness of the plate, the problem would be mode I, but due to the slant the local conditions along the cra...

We propose two possible representative models for a 2D fracture in reservoirs. The first one simulates the fracture as a low-aspect ratio elliptical cylinder. The inner properties of this elliptical cylinder are assumed to be homogeneous and different from the surrounding medium that is also homogenous. This model can approximately describe the actual shape of fractures observed in the field, a...

There are many ways that women support their use of crack cocaine, including sex-for-crack bartering and other forms of prostitution. Empirical studies conducted in the mid-1970s and in the mid-1980s in New York City, and in Chicago in the late 1980s to early 1990s are compared, analyzing similarities and differences between the contemporary crack-prostitution scene and previous prostitution sc...

Failure analysis and fatigue life prediction are necessary and critical for engineering structural materials. In this paper, a general methodology is proposed to predict fatigue life of smooth and circular-hole specimens, in which the crack closure model and equivalent initial flaw size (EIFS) concept are employed. Different effects of crack closure on small crack growth region and long crack g...