Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"shear fracture"”.
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Shear Fracture Growth in Granular Rocks and Porosity-Permeability Relationships in Mudstones
… of 0–50 MPa, leading to the development of shear fractures through interaction of emergent microcracks occurring in shear and tensile modes. I document the mode and energy associated with microcracks to analyze fracture growth patterns and quantify energy release. Shear fracture growth in my …
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Characterization of Fractures Subjected to Normal and Shear Stress
… a series of laboratory experiments to determine fracture specific stiffness, for a fracture subjected to shear and normal stress, are presented and analyzed. The experimental work focuses on the determination of relations between normal and shear fracture specific stiffness and between spatial …
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Projectile impact damage in filament wound CFRP tubes : effect of stacking sequence on projectile kinetic energy dissipation
… in order to determine the normal laminate shear fracture energy release rate and energy dissipated by friction between the projectile and laminate.
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Surface analysis of sheet molded composite (SMC) material as related to adhesion
… treatments as well as after mechanical lap shear fracture tests for SMCs bonded with urethane adhesive. Surface chemical functionalities, including -C-0·R(X)/-NCOZR and -C=0 (ester carbonyl) groups, were found to promote good adhesion using urethane adhesives. These chemical …
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Prediction of ductile crack formation in uncracked bodies
… ductile crack formation mechanisms occur ("shear fracture" in negative stress triaxialities, void nucleation, growth, and linkage in high stress triaxialities, a transition mode in intermediate stress triaxialities). A cut off value at the stress triaxiality of -1/3 is discovered. Effects of …
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Fracture toughness determination and micromechanics of rock under Mode I and Mode II loading
… method for the determination of Mode II (shear) fracture toughness, KIIC of rock and compares the outcome to results from Mode I (tensile) fracture toughness, KIC, testing using the International Society of Rock Mechanics Chevron-Bend method.Critical Mode I fracture growth at ambient …
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Influence of topographic stress on rock fracture : a two-dimensional numerical model for arbitrary surface topography and comparisons with borehole observations
… in some landscapes may be large enough to fracture rocks, which in turn could influence slope stability, erosion rates, and bedrock hydrologic properties. These predictions typically have involved idealized topographic profiles, with few direct comparisons of predicted topographic stresses …
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Effect of microstructure on the fracture response of advanced high strength steels
… to impose a localized through-thickness shear fracture. Samples of each AHSS grade were strained to progressively higher percentages of their failure displacement, and microstructural damage was observed using a scanning electron microscope on a metallographic section removed from the …
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Investigating Wood Welding Parameters Using a Prototype Welding Machine
… on the basis of bond coverage and ultimate shear strength. Four experiments were performed: welding frequency and duration interaction, grain orientation effects, alternative welding completion metrics, and strength development over time. During the wood welding process, three distinct …
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Fracturing processes and induced seismicity due to the hydraulic fracturing of rocks
… such as the propagation of the newly-created fractures and interaction between natural and newly-created fractures, which are not well understood. Since data from field hydraulic stimulations may be difficult to obtain and interpret, laboratory testing and numerical modeling play a major role …
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The effect of microstructure on the fracture toughness of a high strength steel
… between heat treatment, microstructure, fracture topography and room temperature fracture toughness has been determined for a high strength low-alloy steel, En 25. 0ptical, transmission and scanning electron microscopy were used to characterize the structure and morphology while fracture …
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Aspects of serrated flow in aluminium alloys
… electron microscope ( CTEM) as well as the final fracture mode. The existence of a characteristic shear fracture mode was consistently observed to follow tensile deformation which had been dominated by unstable plastic flow. The ready occurrence of dynamic recovery and the associated formation of …
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Characterization of anisotropy in organic-rich shales: shear and tensile failure, wave velocity, matrix and fracture permeability
Lamination and fractures are common features in organic-rich shales. The objective of this thesis is to determine the impact of lamination and fractures on elastic properties, shear and tensile failures, and the permeability of organic-rich shales. The elastic properties of rocks determine the …
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Quantum and atomistic simulation of mechanical and electronic properties of nano-materials
… properties of graphene under tensile and shear deformation. Using TB and MD simulations, we computed the modulus of elasticity, fracture strength, and shear fracture strain of zigzag and armchair graphene structures at various temperatures. We also compared the result of two different …