Fracture propagation, especially for fractures emanating from inclined wellbores and closed natural fracture often involves Mode I, Mode II and at times Mode III fracture pattern. When an embedded inclined 3D fracture is subjected to compression, the fracture tips are restrained by the surrounding materials so that it does not propagates as predicted by 2D fracture models. In this paper, threed...

background and aim: the present study aimed at determination of the fatigue resistance and failure mode of cusp-replacing onlays in endodontically treated premolars using indirect composite resin restorations. materials and method: in this experimental study, 84 human premolars were randomly divided into 7 groups of 12. these groups were prepared as follows: intact teeth used in group1 as contr...

To determine how fracture–vuggy structure, pressure, and injection–production mode influence displacement efficiency in the water flooding process in fracture–vuggy reservoirs, two types of models were built based on the characteristic of such reservoir: two fracture models with different fracture apertures and two fracture– vuggy models with different sizes of vugs. A series of twophase fluid ...

A mode-dependent embedded-process-zone (EPZ) model has been developed and used to simulate the mixed-mode fracture of plastically deforming adhesive joints. Mode-I and mode-II fracture parameters obtained from previous work have been combined with a mixed-mode failure criterion to provide quantitative predictions of the deformation and fracture of mixed-mode geometries. These numerical calculat...

Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodolo...

A new test method has been developed to measure the resistance of dynamic fracture initiation in brittle materials under combined mode I/I loadings. The Brazilian disks with center-cracks have been fractured under oblique impact loadings in diarnetral-compression. The dynamic stress intensity factors of mode I and H are evaluated from the superposition integrals of the step response functions f...

Turbine-generator shafts are often subjected to a complex transient torsional loading. Such transient torques may initiate and propagate a circumferential crack in the shafts. Mode III crack growth in turbo-generator shafts often results in a fracture surface morphology resembling a factory roof. The interaction of the mutual fracture surfaces results in a pressure and a frictional stress field...

Following our innovative experimental spontaneous fracture models for frictional fractures (compression and shear) and mixed-mode fractures (tension and shear) in identical materials, we designed a laboratory model to investigate the effects of material contrast on mixed-mode spontaneous fracture along a bimate-rial interface. A series of interesting phenomena are observed, including asymmetry ...

introduction: the restoration of endodontically treated teeth is a topic that has been studied extensively but it is still a challenge for dental practitioners. the aim of this study was to evaluate fracture resistance, fracture patterns and fracture location of endodontically treated human maxillary premolars restored with direct and indirect composite resin and ceramic restoration. methods: e...