Global ETD Search
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Showing 1 to 20 of 21 for “"brittle-ductile transition"”.
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Studies on the Brittle -Ductile Transition in Silicon
After a specimen geometry that ensures straight crack growth was found for the experiment described above, research on crack turning was continued. As a hot glass plate is dipped into cool water, a pre-crack may grow along many different paths depending upon the testing parameters. In silicon the …
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The role of dislocation activities in the brittle-ductile transition in silicon single crystals
To determine the controlling mechanisms in the brittle-ductile transition (BDT) in silicon single crystals, one must identify the conditions for dislocation nucleation at crack tips. In the present study, dislocation nucleation in $\{110\}$$$ oriented silicon is determined experimentally. The …
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Characterization of Structures and Deformation in the Brittle-Ductile Transition, Western Termination of the Chugach Metamorphic Complex, Southern Alaska
… and that the Stuart Creek fault is a younger brittle fault with 90km of dextral offset. Electron Back Scatter Diffraction (EBSD) and microstructural observations revealed deformation mechanisms were primarily compositionally controlled, whereas P-T-t conditions played a secondary role. Other …
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Controls on the diversity of the fault slip styles at the brittle-ductile transition: examples from the Cape Fold Belt, Nuy Valley, South Africa
… rheological division, with pressure-dependent brittle deformation predominating at shallow depths, and temperature-dependent viscous deformation occurring in the deeper levels of the crust. The brittle-ductile transition zone separates these two regimes, it occurs at approximately 350°C for …
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Effets des agents interfaciaux copolymères tribloc sur le comportement en rupture et en écoulement du mélange de polystyrène/caoutchouc-éthylène-propylène
… known as an interfacial modifier, allows the brittle PS/EPR blend to become more ductile. The time-temperature dependence of the brittle-ductile transition in fracture performance of the blends is controlled by an energy activation process and can be predicted by the Arrhenius …
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Shearing on the Great Glen Fault: Kinematic and Microstructural Evidence Preserved at Different Crustal Levels
… and overlying Devonian sedimentary rocks for brittle upper-crustal shearing on the GGF. However, evidence for high-temperature crystal plastic shearing at deeper crustal levels on the GGF, potentially of Silurian to Early Devonian age, is limited. During summer 2022, suites of oriented and …
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Adhesion study of thermoplastic polyimides with Ti-6Al-4V alloy and PEEK-graphite composites
High glass transition (eg. 360 °C) melt processable thermoplastic polyimide homopolymers and poly(imide-siloxane) segmented copolymers were prepared from a number of diamines and dianhydrides via solution imidization, polydimethylsiloxane segment incorporation and molecular weight control with …
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Seismic tomography and surface deformation in Krýsuvík, SW Iceland
… faults above and around this low velocity zone. Brittle-ductile transition is delineated based on the distribution of the earthquakes in this area. In order to understand the relation between the subsurface structure and the surface deformation, we modeled surface deformation using the input …
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The influence of nitrogen on the plasticity of diamond
… these types of test introduce a large degree of brittle failure in ultra-hard, covalently bonded materials. The soft impressor technique, on the other hand, allows large pressures to be applied without large stress concentrations. The result is that plastic deformation can be more readily induced …
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Experimental assessment of cracked steel beams under mechanical loading and elevated temperatures
… types of fractures were observed including brittle fracture, ductile fracture, and brittle/ductile transition failure, which depended on the temperature distribution. The results presented include load versus displacement and time versus temperature curves. In addition, digital image …
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The architecture and evolution of intracontinental orogens: a structural, metamorphic and geochemical characterisation.
… is characterised by intensely metasomatised ductile shear zones that dissect the eastern Arunta Region. Similar alteration features are also observed in the Cambrian–Ordovician (514–490 Ma) Delamerian Orogen, southern Curnamona Province. In both cases, isotopic datasets confirm that …
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The oxygen isotope composition of the country rock of the Koegel Fontein igneous complex
… meteoric water passed through the BFSZ, into the brittle-ductile transition zone. A cold climate only coincides with a suitable tectonic setting during the Pan-African Orogeny, suggesting that the 18O-depletion is syn-tectonic. Furthermore, strong recrystalisation and annealing after deformation …
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Mechanical properties and microcracking behaviour of heterogeneous rocks after high-temperature treatment
… showed that the rock gradually changed from brittle to ductile. The length and width of the fracture process zone increased with the increase of temperature. The length-to-width ratio of the fracture process zone was concentrated in 2~3 at lower temperatures (25~400 °C), while it increased to …
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Fluid inclusions as a monitor of progressive grain-scale deformation during cooling of the Papoose Flat pluton, eastern California
… of samples from all three domains confirmed the transition from magmatic flow in the core of the pluton to solid-state deformation at the pluton margin. However, weakly developed solid-state microstructures overprint the dominant magmatic microstructures in samples from the core domain. The …
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Three-dimensional thermo-mechanical modeling of deformation at plate boundaries : case study San Andreas Fault System
… tools. Among them is the necessity to handle the brittle-ductile transition within the single computational domain, adequately represent the rock rheology in a broad range of temperatures and stresses, and resolve the extreme deformations of the free surface and internal boundaries. In the …
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The application of the soft impression technique to evaluate flow stress, creep and frictional deformation of polycrystalline diamond and cubic boron nitride
… regimes. In regime I, the deformation is brittle and fracture occurs above a given mean pressure; in regime II dislocations are mobile and the flow stress decreases sharply as the temperature rises; and in regime III the flow stress is independent of the temperature.# In the earlier work, …
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Tectono-metamorphic history of the re-worked, high-grade Maud Belt at central-Eastern H.U. Sverdrupfjella, Antarctica
… was at crustal conditions approximating the brittle-ductile transition. The study area in central-Eastern H.U. Sverdrupfjella preserves the peak and retrograde metamorphic assemblages from the Grenvillian orogeny and does not display evidence of reworking by a later granulite facies event. …
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Crustal heterogeneities and complexities of fault processes
… may be interpreted as induced, close to the brittle-ductile transition, by high pressure fluids migrating upwards within the tensile quadrants; this process increases the deviatoric stress within the asperity which eventually fails, becoming the hypocenter of the mainshock, on the optimally …
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Brittle-viscous deformation cycles at the base of the seismogenic zone in the continental crust
… study was to determine the dynamical cycle of ductile-brittle deformation and to characterise the fluid pathways at different scales of a brittle-viscous fault zone active at the base of the seismogenic crust. Object of analysis are samples from the sinistral strike-slip fault zone BFZ045 from …
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