scholarly journals The Role of Fabric in Frictional Properties of Phyllosilicate-Rich Tectonic Faults

10.3791/62821 ◽  
2021 ◽  
Author(s):  
Cristiano Collettini ◽  
Telemaco Tesei ◽  
Fabio Trippetta ◽  
Marco M. Scuderi ◽  
Eliza Richardson ◽  
...  
Keyword(s):  
Frictional Properties ◽  
Tectonic Faults

scholarly journals The role of effective normal stress, frictional properties, and convergence rates in characteristics of simulated slow slip events

2015 ◽  
Vol 42 (4) ◽  
pp. 1061-1067 ◽  
Author(s):  
W. David Watkins ◽  
Harmony V. Colella ◽  
Michael R. Brudzinski ◽  
Keith B. Richards-Dinger ◽  
James H. Dieterich
Keyword(s):  
Normal Stress ◽  
Convergence Rates ◽  
Slow Slip ◽  
Slow Slip Events ◽  
Frictional Properties ◽  
Effective Normal Stress

Permeability and frictional properties of halite-clay-quartz faults in marine-sediment: The role of compaction and shear

2016 ◽  
Vol 78 ◽  
pp. 222-235 ◽  
Author(s):  
Bryan M. Kaproth ◽  
Marek Kacewicz ◽  
Sankar Muhuri ◽  
Chris Marone
Keyword(s):  
Marine Sediment ◽  
Frictional Properties

Investigation into the effect of proteoglycan molecules on the tribological properties of cartilage joint tissues

1998 ◽  
Vol 212 (3) ◽  
pp. 177-182 ◽  
Author(s):  
J Pickard ◽  
E Ingham ◽  
J Egan ◽  
J Fisher
Keyword(s):  
Tribological Properties ◽  
Sliding Friction ◽  
Chondroitin Sulphate ◽  
Constant Load ◽  
Compression Tests ◽  
Bovine Articular Cartilage ◽  
Frictional Properties ◽  
Proteoglycan Content ◽  
Bovine Cartilage

The aim of this research was to investigate the role of the hydrophilic properties of the proteoglycan molecules within the cartilage matrix, on the tribological properties of joint tissues in the mixed and boundary lubricating regime. Bovine articular cartilage, bovine meniscus and bovine cartilage that had been degraded to remove the chondroitin sulphate from its proteoglycans were studied in order to investigate differences in their friction and compression responses. The tissues were tested on a sliding friction rig under nominal contact stresses of 0.5 and 4 MPa. The compression tests were carried out under a 0.8 MPa contact stress. The compression tests showed the cartilage and meniscus deforming at the same rates, but the degraded cartilage deformed more quickly to reach its equilibrium position in a shorter period of time. The friction tests carried out at a constant load revealed the friction of the meniscus rising more rapidly with loading time than the cartilage. The degraded cartilage followed an almost identical curve as the untreated cartilage. Although the reduced proteoglycan content of the degraded cartilage substantially altered the biphasic compression response, it did not have an effect on the frictional properties of the tissue.

Frictional properties and slip stability of active faults within carbonate–evaporite sequences: The role of dolomite and anhydrite

2013 ◽  
Vol 369-370 ◽  
pp. 220-232 ◽  
Author(s):  
Marco M. Scuderi ◽  
André R. Niemeijer ◽  
Cristiano Collettini ◽  
Chris Marone
Keyword(s):  
Active Faults ◽  
Frictional Properties

Effect of Texturing on the Friction Characteristic of Carbide and Steel Material by Grinding Process

2017 ◽  
Vol 887 ◽  
pp. 83-88
Author(s):  
Asma Perveen ◽  
Feng Liu
Keyword(s):  
Steel Surface ◽  
Friction Reduction ◽  
Grinding Wheel ◽  
Friction Behavior ◽  
Friction Characteristic ◽  
Frictional Properties ◽  
Steel Material ◽  
Steel Surfaces ◽  
Grooved Wheel

In this paper, friction behavior of textured carbide and steel surface has been studied in order to investigate the effect of different patterns. Several simple textures have been fabricated using straight groove grinding wheel. By microstructuring, various spacing and height of the structure, we investigate the role of topography in terms of friction characteristic. The change of friction behavior has been tailored by grinding operation using straight grooved wheel and evaluated in terms of friction. Friction values were measured by Tribometer. Frictional properties of textured carbide and steel surfaces were assessed with the help of parallel steel slider with 2000g normal force under dry condition using four different sliding speeds. It is found from the experiment that except 30° and 90° angle patterns, rest of the patterns on carbide surfaces show friction reduction which is roughly from 0.15 to 0.13. On the other hand, similar textured patterns can reduce the COF from 0.17 to 0.13 in case of steel surface.

scholarly journals The Effect of Addition of Nanoparticles, Especially ZrO2-Based, on Tribological Behavior of Lubricants

Lubricants ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 23 ◽  
Author(s):  
Adam Rylski ◽  
Krzysztof Siczek
Keyword(s):  
Friction Coefficient ◽  
Tribological Behavior ◽  
The Other ◽  
Zro2 Nanoparticles ◽  
Lubrication Mechanism ◽  
Lithium Grease ◽  
Frictional Properties ◽  
The Difference ◽  
Ball On Disc

The aim of the paper was to discuss different effects, such as, among others, agglomeration of selected nanoparticles, particularly those from zirconia, on the tribological behavior of lubricants. The explanation of the difference between the concepts of ‘aggregation’ and ‘agglomeration’ for ZrO2 nanoparticles is included. The factors that influence such an agglomeration are considered. Classification and thickeners of grease, the role of additives therein, and characteristics of the lithium grease with and without ZrO2 additive are discussed in the paper. The role of nanoparticles, including those from ZrO2 utilized as additives to lubricants, particularly to the lithium grease, is also discussed. The methods of preparation of ZrO2 nanoparticles are described in the paper. The agglomeration of ZrO2 nanoparticles and methods to prevent it and the lubrication mechanism of the lithium nanogrease and its tribological evaluation are also discussed. Sample preparation and a ball-on disc tester for investigating of spinning friction are described. The effect of ZrO2 nanoparticles agglomeration on the frictional properties of the lithium grease is shown. The addition of 1 wt.% ZrO2 nanoparticles to pure lithium grease can decrease the friction coefficient to 50%. On the other hand, the agglomeration of ZrO2 nanoparticles in the lithium grease can increase twice the friction coefficient relative to that for the pure grease.

scholarly journals Thermobaric depth settings of sedimentary rock basins and their fluid dynamics: Сommunication 2. Superhigh pressures and mud volcanoes

2019 ◽  
Vol 1 (1) ◽  
pp. 44-59
Author(s):  
V. N. Kholodov
Keyword(s):  
Fluid Dynamics ◽  
Organic Matter ◽  
Volcanic Activity ◽  
Sedimentary Rock ◽  
Oil And Gas ◽  
Mud Volcanoes ◽  
Oil And Gas Fields ◽  
Tectonic Faults ◽  
Gas Fields

The article discusses the patterns of placement of mud volcanoes, their spatial connection with tectonic faults, anticlinal uplifts, oil and gas fields. The connection of mud volcanic activity with ultrahigh pressures arising in the clay strata of the stratisphere as a result of phase transformations of clay minerals and organic matter is argued. The role of earthquakes in the formation of fractured clays, increasing their permeability and the formation of mud crates is emphasized. On the example of the mud volcano Aligula (Turkmenistan), the processes of dilution of sandstones and clays, the formation of volcanic mud-crates are considered.

The role of shale content and pore-water saturation on frictional properties of simulated carbonate faults

2021 ◽  
Vol 807 ◽  
pp. 228811
Author(s):  
R. Ruggieri ◽  
M.M. Scuderi ◽  
F. Trippetta ◽  
E. Tinti ◽  
M. Brignoli ◽  
...  
Keyword(s):  
Pore Water ◽  
Water Saturation ◽  
Frictional Properties

The role of fluid chemistry on permeability and fault strength evolution in granite

2020 ◽  
Author(s):  
Catalina Sanchez ◽  
Giuseppe Saldi ◽  
Tom Mitchell ◽  
Francesco lacoviello ◽  
Philip Meredith ◽  
...  
Keyword(s):  
Clay Minerals ◽  
Fault Plane ◽  
Mineral Dissolution ◽  
New Mineral ◽  
Geothermal Systems ◽  
Rock Interaction ◽  
Frictional Properties ◽  
Mineral Phases ◽  
Reservoir Permeability

<div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <p>Efforts to maintain and enhance reservoir permeability in geothermal systems can contribute to lowering CO<sub>2</sub> emissions and sourcing more sustainable energy. The evolution of permeability in geothermal reservoirs is strongly affected by interactions between the host rock and the fluids flowing through the rock’s permeable pathways. Mineral dissolution, which results from fluid-rock chemical reactions within the fracture network, can significantly enhance reservoir permeability, whereas the precipitation of secondary mineral phases, that are also the products of fluid-rock reactions, can significantly reduce the permeability of the system. The interplay between these two important processes dictates the long-term productivity and lifetime of the reservoir. In the study reported here, we have attempted to simulate the conditions within a geothermal reservoir from initially induced fracturing to the final precipitation or “clogging” phase. We have performed, sequentially, batch, flow-through and circulating flow experiments on cores of the Carnmenellis granite, the target unit of geothermal projects in Cornwall (UK), to understand the role of mineral dissolution and precipitation in controlling the permeability of the system. The physico-chemical properties of the cores are monitored after each reaction-phase using ICP-OES, SEM, hydrostatic permeability measurements, and X-ray Computed Tomography.</p> <p>Our results show that the evolution of the permeability is strongly dependant on the chemistry of the permeating fluid. We find that undersaturated fluids (pH<sup> </sup>10-10.5) dissolve the most abundant mineral phases in the granite (quartz and feldspars), thus creating micro-cavities along the main fracture traces that lead to enhanced but essentially pressure-independent permeability. These results suggest that the creation of chemical dissolution in the early stages of geothermal operations could generate permeable pathways that are less sensitive to effective stress and will likely remain open at higher pressures. Similarly, maintaining the circulation of undersaturated and relatively high-pH fluids (pH<sup> </sup>10-10.5) through these granitic reservoirs could prevent the precipitation of clogging mineral phases and preserve reservoir permeability in granite-hosted geothermal systems.</p> <p>By contrast, we find that supersaturated fluids (pH<sup> </sup>9-9.5), evolving from extended periods of fluid-rock interaction, promote the precipitation of clay minerals that leads to decreased permeability within the system. In natural systems, such as fault zones, the precipitation of clay minerals on the fault plane can also severely affect the frictional properties of the fault and therefore it's slip mode (seismic or asesismic). Triaxial friction experiments on a direct shear configuration were run on samples extracted from well UD-2, part of the United Downs geothermal drilling campaign. The frictional strength of the drilling cuttings from depths around 2370 (at the intersection with the Porthowan’s fault plane ) show variations from 0.3 to 0.1, while friction results from unaltered granite show a friction coefficient of 0.6. These results suggest that the frictional properties of the Porthowan fault have been modified, due to the precipitation of new mineral phases.</p> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div> </div>

Finite Element Stress Analysis of a Push-Out Test Part II: Free Interface With Nonlinear Friction Properties

1992 ◽  
Vol 114 (2) ◽  
pp. 155-161 ◽  
Author(s):  
A. Shirazi-Adl ◽  
A. Forcione
Keyword(s):  
Boundary Conditions ◽  
Stress Analysis ◽  
Relative Difference ◽  
Shear Stresses ◽  
Free Interface ◽  
Frictional Properties ◽  
Press Fit ◽  
Pull Out ◽  
Push Out

In this second part of a two-part paper, nonlinear frictional properties measured at the bone/porous-surfaced metal interface are used to perform the stress analysis of a push-out test assuming free interface. In this case, the friction at the interface is the only mechanism to resist the externally applied load. Similar to the part I, the model is axisymmetric and consists of two cylinders in contact with each other through the interface. Various relative material properties and boundary conditions are simulated in order to examine their effects on the interface stresses and overall push-out resistance. The role of the force-fit and the load direction (push-out versus pull-out) on the results is also investigated. The computed radial and shear stresses are found to markedly vary both with location along the interface and with the testing configuration. The ultimate push-out resistance is also found to significantly alter as the material arrangement and boundary conditions change. The predicted push-out load augments with an increase in the force-fit and diminishes to nil in the absence of a press-fit. For the cases studied here, there is a relative difference of as large as 13 percent between the push-out response and the pull-out response so far as the interface stresses and the maximum resistance are concerned. Therefore, any comparison between the results of push-out (or pull-out) tests performed with different design configurations appears to be invalid.

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