Abstract The fracture toughness of AlN ceramic matrix composites containing carbon (0.5 vol%), yttria (5.0 and Mo (0.0–4.0 vol%) was evaluated using Vickers indentation. results these measurements were compared to a carbon-free, commercial (ST-200 ALN) as well AlN–Mo compositions from the literature. presence added found correlate with 21% reduction in 0.0 vol% carbon-containing sample, ST-200 ...

Abstract The realistic approximation of structural behavior in a post fracture state by the phase-field method requires information about spatial orientation crack surface at material point level. For directional split, this is specified vector, that defined perpendicular to surface. An alternative approach determination based on standard mechanical arguments, i.e. alignment with direction larg...

The cracking elements method (CEM) is a novel numerical approach for simulating fracture of quasi-brittle materials. This method is built in the framework of conventional finite element method (FEM) based on standard Galerkin approximation, which models the cracks with disconnected cracking segments. The orientation of propagating cracks is determined by local criteria and no explicit or implic...

Linear elastic fracture mechanics predicts that joint orientation is controlled by the stress field in which the joints propagate. Thus joint sets are effective proxies for stress trajectories during joint growth. Complexity in joint orientation indicates stress trajectory variability, a phenomenon quantified using an eigenvalue method that measures dispersion of joint normal vectors (i.e. pole...

Rock anisotropy plays an important role in engineering behavior of rocks. Slates are anisotropic rocks which have long been used for gable roof, floor tiles, borrow materials, and other purposes. The slates studied in this research are calcareous and have a porphyro-lepidoblastic texture. To determine the role of the anisotropy on the tensile strength and fracture pattern, two variables includi...

Sandstones that overlie or that are interbedded with evaporitic or other ductile strata commonly contain numerous localized domains of fractures, each covering an area of a few square miles. Fractures within the Entrada Sandstone at the Salt Valley Anticline are associated with salt mobility within the underlying Paradox Formation. The fracture relationships observed at Salt Valley (along with ...