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Showing 1 to 20 of 30 for “"damage zone"”.
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Fracture Initiation and Propagation in Low Porosity Crystalline Rocks: Implications for Excavation Damage Zone (EDZ) Mechanics
… are commonly associated with introducing some damage to the surrounding rock mass through the initiation and propagation of fractures parallel to the excavation boundary due to disturbance to the in situ stress condition, as well as the excavation process quality. The induced fractures in depth …
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A novel discrete damage zone model and enhancement of the extended finite element method for fracture mechanics problems
… element method (XFEM), and (II) a discrete damage zone model for quasi-static and fatigue delamination in composites. The first method improves XFEM when applied to general nonlinear materials when crack tip analytical solutions are not available. For linear elastic materials, Branch …
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Finite element stress analysis of idealized composite damage zones
… stress and failure analysis of an idealized damage zone in a laminated composite under compressive loading. The following conclusions can be made from results of the analysis. 1. A boundary layer exists around the damage zone; it is similar to the boundary layer along the free edges. 2. …
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Effects of Hurricane Fault Architecture on Groundwater Flow in the Timpoweap Canyon of Southwestern, Utah
<p>Hydrogeologically important features of fault zones include undamaged country rock, the damage zone, and the core zone. Fault cores generally have low porosity and permeability, and often act as a barrier to groundwater flow. The damage zone, by contrast, consists of small faults and fracture …
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Fault damage zones and friction: insights from shallow Japan Trench drill core
The integrated deformation in a fault damage zone provides a record of repeated slip on faults and the properties that control slip behavior. Shear displacement on faults is a frictional phenomenon in the sense that slip begins when the ratio of shear to normal stress surpasses the static friction …
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Acoustic emission evaluation of FRP composite specimens in tension and bending
… loading quarter of the specimens along with the damage zone of the specimens. By concentrating the AE parameters' patterns, Neural Networks were used to predict the loading quarter and damage zone of each specimen.;The connections between structural status and AE parameters found along with the …
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Dike-Driven Hydrothermal Processes on Mars and Sill Emplacement on Europa
… rates would be adequate in the high permeability damage zone adjacent to the dike. However, the lowered permeability outside the damage zone would restrict replenishment flow and could cause the need for water storage and periodic release between flood events as the volume within the damage zone …
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Relationship Between Fault Zone Architecture and Groundwater Compartmentalization in the East Tintic Mining District, Utah
The Eureka Lilly fault zone provides an impermeable barrier for groundwater flow in the East Tintic mining district. The fault zone separates two distinct groundwaters that have different temperatures, compositions, and potentiometric surfaces. The damage zone of the fault is an extensive network …
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Compressive response of notched composite-honeycomb sandwich panels
… key failure mechanism was observed to be linear damage zones (LDZs) emanating from the notch tip (in both materials). LDZ's behaved in a macroscopically similar manner to a bridged crack under tensile loading, and were characterized by semi-stable propagation. Crosssectioning studies revealed the …
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Low-energy electron diffraction effects at complex interfaces
… and 3) low-energy electron induced DNA damage. Zone-specific desorption of Cl+ from Si(111)- 7X7:Cl surfaces was demonstrated. Graphene epitaxially grown on SiC(0001) surfaces was analyzed using Auger electron diffraction and Raman scattering spectroscopy. Finally, the roles of …
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Contribution of Recharge Along Regional Flow Paths to Discharge at Ash Meadows, Nevada
… offset faults near the Ash Meadows springs. The damage zone of the Gravity Fault appears to provide a conduit for groundwater flow; the north-south fractures should have the greatest aperture under the current stress field, and the buried tufa mounds (revealed with ground penetrating radar data) …
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Magnetostrictive Particle Tagging of Epoxy and Epoxy Composites for Self Assessment of Damage
… of using magnetostrictive tags to detect damage in a structural composite. The brittle nature of the failure process of polymer matrix composite poses a technical challenge for their introduction in structural applications. Thus, there is a critical need to develop new techniques to …
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Hypocenter Locations and Focal Mechanism Solutions of Earthquakes in the Epicentral Area of the 1886 Charleston, SC, Earthquake
… a south-striking, west-dipping seismogenic zone in the upper 12 km of the crust. Over 40% of the 66 well-constrained focal mechanisms show reverse faulting on approximately north-south trending nodal planes, consistent with the orientation of the tabular hypocenter distribution. I offer the …
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Effects of fault failure parameterization and bulk rheology on earthquake rupture
… formation, inelastic deformation in the fault damage zone, and others. Due to the computational complexity of earthquake models, especially if complex fault geometries and heterogeneity of properties are also considered, all of these failure related processes are usually combined into their …
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Fatigue crack growth in ceramics containing a viscous grain boundary phase at elevated temperatures
… on cyclic fatigue-crack growth behavior. A damage zone was observed ahead of the crack tip in which grain boundary cavitation (or microcracking) occurred during fatigue-crack growth. An analytical model based upon the damage accumulation in the grain boundary phase was developed that …
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An analysis of the morphology and volcano-tectonic structure of the Central Indian Ridge between 18º and 21ºS
… Analysis of the data shows that the fracture zones have a significant structural control on along-axis morphology and melt supply, partitioning the ridge into three morphologically defined regions. The central region (Region B) bounded by two of the fracture zones, contains segments which show …
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Faults as episodic conduits for hydrocarbons, CO2 and groundwater in sandstones
… may permit fluid flow to enter a fault zone, resulting in cementation (strengthening) or alteration (weakening) of the fault and host rocks.;The resulting changes in rock strength may enhance or retard further fracturing and may even result in a switch of deformation mechanism.;Temporal …
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Damage characterization and modeling of notched graphite/epoxy sandwich panels in compression
Damage tolerant design, which focuses on a structure's ability to perform in a damaged state, is widely used in the aerospace industry today. Although extensive research has been carried out in this area for notched composite laminates, a relatively small fraction has dealt with compressive loading …
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Biomineralized structural materials with functional optical properties
… abiotic calcite. 3D quantitative analysis of the damage zone resulting from high load indentations was performed via synchrotron X-ray micro-computed tomography, revealing the formation of a complex network of microcracks. A unique structural motif, screw dislocation-like connection centers, is …
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New Constraints on Fault-Zone Structure from Seismic Guided Waves
The structure of fault zones (FZs) plays an important role in understanding fault mechanics, earthquake rupture and seismic hazards. Fault zone seismic guided waves (GW) carry important information about internal structure of the low-velocity fault damage zone. Numerical modeling of observed FZGWs …
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