Дисертації з теми "Brittle and ductile rock"
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Ueda, Tadamasa. "Seismogenic deformation structures in the brittle-ductile transition regime: a case study of ultramafic pseudotachylytes and related deformed rocks in the Balmuccia peridotite body, Italy." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/204571.
Повний текст джерелаMahé, Stéphanie. "Etude de la fracturation et de la déformation d'un massif rocheux aux abords d'une faille d'échelle crustale dans le cadre du tracé du tunnel routier de Saint-Béat." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20254/document.
Повний текст джерелаThe Saint-Béat massif, composed of different marble facies, is part of the Internal Metamorphic Zone of the French Central Pyrenees. It is formed by Mesozoic sediments metamorphosed by the High Temperature – Low Pressure extensional event, classically described in the Pyrenees. The aim of this work is to characterize the deformation and fractured state of the massif, and to understand how the former can constrain the latter. The ductile deformation state is recorded in calcite grains for Mesozoic rocks, or in quartz grains for Paleozoic rocks. Their preferential lattice orientations have been measured with the EBSD method. Calcite texture observations give indications about deformation rates and temperatures. These results, in addition with field observations, allow us to rebuild the structural evolution of the massif, from the Albian extension. Fracturing along the massif is described at different scales. Four outcrops are selected in order to characterize and to classify fractures, and locally reconstruct the paleo stress tensor. The obtained tensors are presented and compared to those already published. Three slightly different marble facies are used to discuss the degree of anisotropy of the rock. Mechanical experiments such as compression tests, tensile tests and velocity measurements of elastic waves are carried out on oriented cores within these three facies. These results provide internal rock characteristics which are discussed and compared for the three facies, and for different orientations of the cores
Morgan, Robert Edward. "Ductile-brittle transitions in pipe grade polyethylene." Thesis, Imperial College London, 1994. http://hdl.handle.net/10044/1/7399.
Повний текст джерелаBannister, Michael Keith. "Toughening of brittle materials by ductile inclusions." Thesis, University of Cambridge, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292024.
Повний текст джерелаSamuels, J. "The brittle to ductile transition in silicon." Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382682.
Повний текст джерелаVenkatachalam, Sivaramakrishnan. "Predictive Modeling for Ductile Machining of Brittle Materials." Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19774.
Повний текст джерелаMohseni, Peyman. "Brittle and Ductile Fracture of X80 Arctic Steel." Doctoral thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for materialteknologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-19487.
Повний текст джерелаSerbena, F. C. "The brittle-ductile transition of NiAl single crystals." Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.294341.
Повний текст джерелаEllis, M. "The ductile to brittle transition in BCC metals." Thesis, University of Oxford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306220.
Повний текст джерелаJeng, Fu Shu. "Deep penetration into frictional ductile and brittle materials." Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13096.
Повний текст джерелаZhao, Yue. "How Plasticizer Makes a Ductile Polymer Glass Brittle?" University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460160287.
Повний текст джерелаLu, Yue. "Polystyrene Glasses Under Compression: Ductile and Brittle Responses." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1523271245493476.
Повний текст джерелаDo, Xuan Nam. "Localized failure in dynamics for brittle and ductile materials." Thesis, Compiègne, 2017. http://www.theses.fr/2017COMP2356.
Повний текст джерелаFailure of engineering materials and structures can be considered as a result of a complex interplay between different physical phenomena such as nucleation of cavities, microcracks,microvoids and other irreversible processes. These micro-defects eventually coalesce into one or more macro-cracks leading to a decrease in the load-bearing capability and finally, to failure of the structure under consideration. Prevention of failure of structures and structural parts has always been a critical subject and a major concern in engineering. This thesis aims to represent localized failure in non linear materials without mesh dependency. Of special interest will be the case of dynamic strain-softening. Localized phenomena are taken into account by using the embedded strong discontinuities approach in which the displacement field is enhanced to capture the discontinuity. Based upon this approach, a one-dimensional model for elasto-plastic bar capable of representing failure for ductile materials with combined hardening in FPZ-fracture process zone and softening with embedded strong discontinuities was first developed. Results comparing the proposed one-dimensional model to (semi-) analytical works are presented. It was shown that the proposed strategy provides mesh independent solutions. Strain increases in the softening domain with a simultaneous decrease of stress. The problem unloads elastically outside the strain softening region. The strain energy is found to vanish. The model was also compared with a one dimensional damage model capable of representing the dynamic fracture for elasto-damage bar with combined hardening in fracture process zone - FPZ and softening with strong embedded discontinuities to find a good agreement between two models. A two-dimensional finite element model was developed, capable of describing both the diffuse damage mechanism accompanied by initial strain hardening and subsequent softening response of the structure. The results of several numerical simulations, performed on classical mechanical tests under slowly increasing loads such as Brazilian test or three-point bending test were analyzed. The proposed dynamics framework is shown to increase computational robustness. It was found that the final direction of macro-cracks is predicted quite well and that influence of inertia effects on the obtained solutions is fairly modest especially in comparison among different meshes. This two-dimensional model was expanded further into the two dimensional continuum viscodamage-embedded discontinuity model to help briefly explore the implementation of the second order mid-point scheme that can provide improved results under limitation of viscous regularization of localized failure damage model
Bezenšek, Boštjan. "Elastic-plastic crack problems in the ductile-brittle transition." Thesis, University of Glasgow, 2003. http://theses.gla.ac.uk/6946/.
Повний текст джерелаKomoroczi, Andrea [Verfasser]. "Numerical simulation of combined brittle-ductile deformation processes / Andrea Komoroczi." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1076096107/34.
Повний текст джерелаJoseph, T. D. "Materials for Fusion Reactors - The Brittle-Ductile Transition in Vanadium." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.491624.
Повний текст джерелаEberhardt, Erik Brian. "Brittle rock fracture and progressive damage in uniaxial compression." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0008/NQ27403.pdf.
Повний текст джерелаNarström, Torbjörn. "Microstructural aspects of the ductile-to-brittle transition in pressure vessel steels." Doctoral thesis, KTH, Materials Science and Engineering, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3007.
Повний текст джерелаHütter, Geralf. "Multi-scale simulation of crack propagation in the ductile-brittle transition region." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2013. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-121281.
Повний текст джерелаIn der vorliegenden Arbeit wird die Rissausbreitung im spröd-duktilen Übergangsbereich auf zwei Skalen mittels deterministischer Modelle untersucht. Das duktile Versagen wird im makroskopischen Modell durch ein nichtlokales Gurson-Modell beschrieben, während im mikroskopischen Modell die Porenmikrostruktur im Bereich um die Rissspitze diskret aufgelöst wird. Das mögliche Versagen durch Spaltbruch wird nicht, wie üblich, nachträglich durch ein spannungsbasiertes Kriterium bewertet. Stattdessen wird der Spaltbruch auf beiden Skalen durch ein Kohäsivzonenmodell abgebildet. Somit wird die Spaltbruchinitiierung nicht a priori mit instabiler Rissausbreitung gleichgesetzt. Vielmehr ist die Stabilität der Rissausbreitung ein Ergebnis der Simulationen. Außerdem wird das Problem der der Handhabung vollständig ausgefallenen Materials im Rahmen nichtlokaler Schädigungsmodelle herausgestellt. Es wird eine Methode vorgestellt, dieses Problem zu behandeln und erfolgreich angewendet. In den Simulationen wird der Fall vollständig eingebetteten, plastischen Fließens untersucht. Die Simulationen mit dem makroskopischen Modell geben viele Effekte wieder, die aus Experimenten bekannt sind. Dazu zählen die Ausbildung von Stretchzonen, die Spaltbruchinitiierung nach anfänglichem, duktilem Reißen oder lokale Instabilitäten mit Rissarrest. Die mikroskopischen Simulationen tragen zum Verständnis des makroskopisch beobachteten Verhaltens bei. In der vorliegenden Arbeit werden systematische Parameterstudien durchgeführt. Zunächst werden Grenzfälle wie das rein duktile Versagens oder der Spaltbruch in Abwesenheit der Mikroporen untersucht, um die Einflüsse der einzelnen Materialparameter abzugrenzen. Ausgehend von diesen Ergebnissen wird eine Prozedur vorgeschlagen, die Materialparameter des makroskopischen Modells Schritt für Schritt aus Experimenten zu bestimmen. Diese Prozedur wird erfolgreich auf experimentelle Daten aus der Literatur angewendet. Die Ergebnisse zeigen, dass es das entwickelte Modell erlaubt, das Verhalten einer Bruchmechanikprobe mit geringer Dehnungsbehinderung an der Rissspitze mit denjenigen Materialparametern vorherzusagen, die an Proben mit einer hohen Dehnungsbehinderung ermittelt wurden
Kamel, Simon. "The effects of constraint and residual stress on ductile and brittle fracture." Thesis, Imperial College London, 2010. http://hdl.handle.net/10044/1/11425.
Повний текст джерелаTanne, Erwan. "Variational phase-field models from brittle to ductile fracture : nucleation and propagation." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLX088/document.
Повний текст джерелаPhase-field models, sometimes referred to as gradient damage, are widely used methods for the numerical simulation of crack propagation in brittle materials. Theoretical results and numerical evidences show that they can predict the propagation of a pre-existing crack according to Griffith’s criterion. For a one- dimensional problem, it has been shown that they can predict nucleation upon a critical stress, provided that the regularization parameter is identified with the material’s internal characteristic length.In this work, we draw on numerical simulations to study crack nucleation in commonly encountered geometries for which closed-form solutions are not available. We use U- and V-notches to show that the nucleation load varies smoothly from the one predicted by a strength criterion to the one of a toughness criterion when the strength of the stress concentration or singularity varies. We present validation and verification of numerical simulations for both types of geometries. We consider the problem of an elliptic cavity in an infinite or elongated domain to show that variational phase field models properly account for structural and material size effects.In a second movement, this model is extended to hydraulic fracturing. We present a validation of the model by simulating a single fracture in a large domain subject to a control amount of fluid. Then we study an infinite network of pressurized parallel cracks. Results show that the stimulation of a single fracture is the best energy minimizer compared to multi-fracking case. The last example focuses on fracturing stability regimes using linear elastic fracture mechanics for pressure driven fractures in an experimental geometry used in petroleum industry which replicates a situation encountered downhole with a borehole called burst experiment.The last part of this work focuses on ductile fracture by coupling phase-field models with perfect plasticity. Based on the variational structure of the problem we give a numerical implementation of the coupled model for parallel computing. Simulation results of a mild notch specimens are in agreement with the phenomenology of ductile fracture such that nucleation and propagation commonly reported in the literature
Li, Song. "Modeling fracture and deformation of brittle rock under compressive loading." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0014/NQ41619.pdf.
Повний текст джерелаJohnsson, Helena. "Plug shear failure in nailed timber connections : avoiding brittle and promoting ductile failures /." Luleå : Univ, 2004. http://epubl.luth.se/1402-1544/2004/03.
Повний текст джерелаCullers, Cheryl Lynne. "Deformation mechanisms of NiA1 cyclicly deformed near the brittle-to-ductile transition temperature." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20050.
Повний текст джерелаCheng, Shiwang. "Tensile Deformation of Polymer Glasses: Crazing, the Brittle-Ductile Transition and Elastic Yielding." University of Akron / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=akron1382525654.
Повний текст джерелаYin, Binghong. "Characterisation of Brittle and Ductile Fracture of 3D-Printed Single-Layer Polymer Films." Thesis, The University of Sydney, 2020. https://hdl.handle.net/2123/24954.
Повний текст джерелаTempest, Simon Aaron. "Fluid-rock interaction in ductile shear zones, central-eastern Pyrenees." Thesis, University of Leeds, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.303629.
Повний текст джерелаGally, Brian James 1970. "Experimental investigation of the brittle to ductile transition in fracture of single crystal silicon." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/85252.
Повний текст джерелаBianculli, Steven. "Fracture of a Brittle-Particle Ductile Matrix Composite with Applications to a Coating System." Research Showcase @ CMU, 2016. http://repository.cmu.edu/dissertations/805.
Повний текст джерелаXu, Wenting. "Molecular Dynamics Simulations of the Size-dependent Brittle-to-ductile Transition of Silicon Nanowires." University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613751523441622.
Повний текст джерелаVanDeVelde, Sharon Ann. "Distribution and Transport of Water in Natural Quartz Arenites Near Brittle-Ductile Transition Conditions." Bowling Green State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1237586551.
Повний текст джерелаDI, BATTISTA EMANUELA. "Interpretation of fracture mechanisms in ductile and brittle materials by the Acoustic Emission Technique." Doctoral thesis, Politecnico di Torino, 2015. http://hdl.handle.net/11583/2607555.
Повний текст джерелаPassa, Eleni. "Study of the microstructure of Nb3Al based alloys." Thesis, University of Surrey, 1996. http://epubs.surrey.ac.uk/843837/.
Повний текст джерелаSwankie, Troy Dennis. "The role of shear and constraint in mixed mode fracture." Thesis, University of Bristol, 1999. http://hdl.handle.net/1983/5021402d-5ea5-435e-a286-6d4e1c6673ce.
Повний текст джерелаTarleton, Edmund. "Dislocation-dynamics modelling of crack-tip plastic zones and brittle-ductile transitions in BCC metals." Thesis, University of Oxford, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.526123.
Повний текст джерелаChao, C. L. "Investigations of the machining of glasses and other normally brittle materials in the ductile regime." Thesis, Cranfield University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302733.
Повний текст джерелаNovovic, Milorad. "Effects of microstructure and prestraining on ductile to brittle transition in carbon-manganese weld metals." Thesis, University of Birmingham, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246758.
Повний текст джерелаAttfield, Peter Richard. "Mechanisms of shear zone deformation." Thesis, Keele University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.253688.
Повний текст джерелаVoskoboinikov, Roman E. "Analytical Description of Brittle-to-Ductile Transition in bcc Metals. Nucleation of dislocation loop at the crack tip." Forschungszentrum Dresden, 2010. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-29522.
Повний текст джерелаPallaspuro, S. (Sakari). "On the factors affecting the ductile-brittle transition in as-quenched fully and partially martensitic low-carbon steels." Doctoral thesis, Oulun yliopisto, 2018. http://urn.fi/urn:isbn:9789526218977.
Повний текст джерелаTiivistelmä Tekijät suurimmista epäjatkuvuuskohdista aina pienimpään alkuaineeseen voivat uhata rakenteellista eheyttä, minkä lisäksi alttius näille kasvaa materiaalin myötölujuuden kasvaessa. Modernit karkaistun tilan ultralujat matalahiiliset rakenneteräkset voivat silti omata riittävän sitkeyden, muovattavuuden ja hitsattavuuden. Tyypillisiä käyttökohteita näille ovat painon suhteen kriittiset ja korkean suorituskyvyn rakenteet. Yleinen ongelma myötölujuudeltaan noin ja yli 900 MPa karkaistun tilan teräksillä on se, että ne eivät noudata perinteistä murtumissitkeyden referenssilämpötilan T₀ ja iskusitkeyden transitiolämpötilan T₂₈ᴊ välistä korrelaatiota, jota käytetään useissa standardeissa ja suunnitteluohjeissa, jotka eivät myöskään vielä salli näin lujien terästen käyttöä. Tämä väitöstyö tutkii transitiolämpötilojen T₀ ja T₂₈ᴊ välistä suhdetta edistääkseen näiden terästen sisällyttämistä standardeihin, haurasmurtuma-sitkeyteen vaikuttavia mikrorakenteellisia tekijöitä sekä yleisellä että paikallisella tasolla, ja vetyhaurautta matalissa lämpötiloissa. Koeteräkset ovat laboratoriovalmisteisia, tuotantokokeita ja tuotantolaatuja. Niitä tutkitaan standardisoiduilla sitkeyskokeilla, mikrorakenteen karakterisoinnilla, fraktografialla ja koheesiovyöhykettä hyödyntävällä mallinnuksella. Tulokset osoittavat karkaistun tilan terästen omaavan erityisen korrelaation T₀ ja T₂₈ᴊ välillä. Muokattu, ultralujat teräkset huomioiva yleinen T₀ – T₂₈ᴊ -korrelaatio soveltuu laajalti eri terästyypeille. T₂₈ᴊ korreloi läheisesti dynaamisen referenssisitkeyden kanssa, jonka avulla yhdessä haitallisten {100} lohkomurtumatasojen osuuden kanssa voidaan estimoida joukko transitiolämpötiloja. Paikallisella tasolla keskilinjasuotauma pienentää efektiivistä karkeiden rakeiden kokoa, mikä suotauman suurista sulkeumista ja kovuudesta huolimatta parantaa murtumissitkeyttä. Vetyhauraus taas huonontaa sitkeyttä ja paikallista muodonmuutoskykyä myös matalissa lämpötiloissa nostaen T₀ lämpötiloja. Kokonaisuutena erinomainen transitiolämpötilasitkeys vaatii efektiivisen karkearaekoon ja vetypitoisuuden minimointia
Hennecke, Thomas [Verfasser], and Thomas [Akademischer Betreuer] Sonar. "Mathematical modeling of the ductile-brittle-transition and an application to ferritic steel / Thomas Hennecke ; Betreuer: Thomas Sonar." Braunschweig : Technische Universität Braunschweig, 2013. http://d-nb.info/1175822906/34.
Повний текст джерелаVoskoboinikov, Roman E. "Analytical Description of Brittle-to-Ductile Transition in bcc Metals. Nucleation of dislocation loop at the crack tip." Forschungszentrum Rossendorf, 2002. https://hzdr.qucosa.de/id/qucosa%3A21779.
Повний текст джерелаGolchinfar, Nader. "Numerical modeling of brittle rock failure around underground openings under statis and dynamic stress loadings." Thesis, Laurentian University of Sudbury, 2013. https://zone.biblio.laurentian.ca/dspace/handle/10219/2103.
Повний текст джерелаBrauer, Nancy A. "Fluid inclusions as a monitor of progressive grain-scale deformation during cooling of the Papoose Flat pluton, eastern California." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/36556.
Повний текст джерелаMicrostructural analysis 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 existence of solid-state microstructures in all three domains indicates that deformation continued during and after crystallization of the interior of the pluton.
Two phase, low salinity (< 26 wt% NaCl equivalent), liquid-rich aqueous fluid inclusions predominate within both quartz and feldspar grains in all samples. Throughout the pluton, the majority of fluid inclusions are hosted by deformed grains. Feldspar-hosted primary inclusions are associated with sericitic alteration. Inclusions were also observed in feldspar as secondary or pseudosecondary inclusions along fractures. Inclusions in quartz are frequently found near lobate grain boundaries or near triple junctions; linear pseudosecondary inclusion assemblages are commonly truncated against lobate boundaries between adjacent quartz grains, indicating that discrete microcracking events occurred during plastic deformation.
Homogenization temperatures overlap for all three microstructural domains. Coexisting andalusite and cordierite in the contact aureole, and the intersection of the Mus + Qtz dehydration reaction with the granite solidus, indicate trapping pressures between 3.8 and 4.2 kb. Ninety-eight percent of the calculated fluid inclusion trapping temperatures at 3.8 - 4.2 kb are below the granite solidus of 650°C. Seventy-six percent of the trapping temperature data fall within the more restricted range of 350-500°C; i.e. at temperatures which are lower than the commonly cited brittle-ductile transition temperatures for feldspar at natural strain rates, but above those for quartz. No correlation could be established between trapping temperatures and either host mineral or microstructural domain within the pluton.
The similar, relatively low trapping temperatures indicate that the majority of inclusions preserved in all three domains were trapped during the late low strain magnitude stages of solid-state deformation. The most common fluid inclusion trapping temperatures (400-500°C) in all three microstructural domains are similar to the deformation temperatures indicated by microstructures and crystal fabrics in the outer part of the pluton; these trapping temperatures are obviously lower than temperatures associated with contemporaneous solid state and magmatic flow in the pluton interior. The similar trapping temperatures within the pluton core and margin must indicate that the inclusion-trapping event migrated from the margin to the core of the pluton as it cooled, because fluid inclusions would rapidly equilibrate to a density appropriate for the PT conditions of their host minerals.
Master of Science
Chan, Hing Chuen Mark. "Automatic two-dimensional multi-fracture propagation modelling of brittle solids with particular application to rock." Thesis, Massachusetts Institute of Technology, 1986. http://hdl.handle.net/1721.1/14977.
Повний текст джерелаMICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING
Vita.
Bibliography: leaves 557-564.
by Hing Chuen Mark Chan.
Sc.D.
Day, Erik. "Characterization of Structures and Deformation in the Brittle-Ductile Transition, Western Termination of the Chugach Metamorphic Complex, Southern Alaska." ScholarWorks@UNO, 2007. http://scholarworks.uno.edu/td/529.
Повний текст джерелаSánchez, Alfaro Pablo. "Interplay between brittle deformation, fluid-rock interaction and mineralization in hydrothermal systems from the Southern Andes." Tesis, Universidad de Chile, 2015. http://repositorio.uchile.cl/handle/2250/135071.
Повний текст джерелаThe interactions between seismic activity, fluid flow and mineral precipitation exerts a first-order control on the strength and permeability of the crust and plays a critical role in promoting the development of hydrothermal systems and the formation of giant ore deposits. However the role of such interactions on the evolution of hydrothermal systems and its transient effects on mineralization is poorly constrained. This thesis contributes to establish the nature of the dynamic interplay between brittle deformation, heat-fluid-rock interaction and mineralization of hydrothermal systems in volcanic arcs. An ideal natural laboratory used to study such interplay is the Andean Cordillera of Central-Southern Chile, where hydrothermal systems occur in close spatial relationship with active volcanism as well as major seismically-active fault systems. The combination of regional-scale structural analysis of active geothermal areas with geochemical modeling of hot springs in the Villarrica Chihuio area in southern Chile unravel the role of crustal deformation in facilitating and inhibiting the development of geothermal systems. Results reveal the presence of two magmatic-tectonic-geothermal domains and indicate that the chemical evolution of hydrothermal fluids in the area is strongly dependent on structurally controlled mechanisms of heat transfer. This contribution provides new insights towards efficient exploration strategies of geothermal resources in Southern Andes. The high enthalpy, metal-rich active Tolhuaca geothermal system north of Villarica was studied in detail in order to (1) address how the interplay between seismic activity, heat-fluid rock interaction, fluid flow and mineral precipitation controls the physicochemical evolution of hydrothermal systems in the studied region and (2) analyze the transient effects of earthquake-triggered pressure perturbations on metal solubility and mineralization. To achieve this, a comprehensive structural and mineralogical analysis at field and drillhole scales was combined with geochemical and thermometric data of borehole fluids and fluid inclusions, and numerical simulations of fluid evolution and rock failure conditions. Results obtained from this study reveal that hydrothermal alteration modifies the response of rock to deformation at Tolhuaca, produces a vertical compartmentalization of the system and promotes the development of a clay-rich low permeability zone. Moreover, they indicate that the life span and thermal structure of this system were highly affected by the low-permeability zone developed on top. Furthermore, thermodynamic modeling of metal (gold) and mineral (silica) solubility at Tolhuaca reveals that the optimum physical and chemical conditions for metal precipitation are reached at liquid-saturated conditions with a saturated liquid temperature less than 310°C, under which small pressure changes triggered by transient fault-rupture can drop solubility several orders of magnitude. The observations resulting from the thesis not only provide new insights about how hydrothermal reservoirs develop through a combination of sustained heat and high permeability conditions that are strongly conditioned by active tectonics, but also unveil how hydrothermal systems evolve to maximize the efficiency earthquake-induced mineral precipitation.
Wang, Hongjian. "Evaluation of Orthogonal Cutting as a Method for Determining Mechanical Properties of Polymers." Thesis, The University of Sydney, 2017. http://hdl.handle.net/2123/16136.
Повний текст джерелаArsène, Sylvie. "Effet de la microstructure et de la température sur la transition ductile-fragile des zircaloy hydrures." Châtenay-Malabry, Ecole centrale de Paris, 1997. http://www.theses.fr/1997ECAP0550.
Повний текст джерелаLessmann, Moritz. "Non-ductile design of demo divertor armour : towards the probabilistic reliability assessment of brittle tungsten components in their irradiated state." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/nonductile-design-of-demo-divertor-armour-towards-the-probabilistic-reliability-assessment-of-brittle-tungsten-components-in-their-irradiated-state(2be9bcee-5d9f-41cc-82fb-4f7b662b0a6a).html.
Повний текст джерела