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Showing 1 to 11 of 11 for “"Cavity expansion"”.
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Behaviour of locked sand during cavity expansion
… enhancements are often neglected. Therefore cavity expansion, in the form of a pressuremeter testing, has been proposed as an alternative method for gathering insitu material data from these deposits. The self-boring pressuremeter is an insitu testing tool with which reliable material …
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Influence of extreme velocities on dynamic cavity expansion
… can broadly be described as the unstable expansion of an empty void in a body, usually occurring when loads on the body reach a critical level. In this thesis, dynamic cavity expansion (DCE) in solids is of particular interest. Cavity expansion has been studied extensively under …
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Addressing Challenges of Volume Controlled Cavity Expansion (VCCE) for In-Vivo Tissue Testing
… mechanical p roperties. Volume Controlled Cavity Expansion (VCCE) is a novel, needle-based probing methodology developed to capture rate dependent ex-vivo and in-vivo tissue material properties. In this thesis, the VCCE methodology was performed on numerous animal tissues as well as …
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An Instrument for the Measurement of Soft Material Nonlinear Mechanical Response
… To overcome this, the Volume Controlled Cavity Expansion (VCCE) method was developed. This technique tests soft materials by controlling the formation rate of a liquid cavity inside the materials at the tip of an injection needle, and simultaneously measuring the resisting pressure which …
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Jamming transition and emergence of fracturing in wet granular media
… four different regimes of the fluid invasion: cavity expansion and fracturing, frictional fingers, capillary invasion, and capillary compaction. We explain fracture initiation as emerging from a jamming transition, and synthesize the system's behavior in the form of a novel phase diagram of …
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Determination of geotechnical properties of seafloor sediment using a free fall penetrometer
… modulus. A dissipation model using a cylindrical cavity expansion method was formulated for this purpose.</p><p>A field study was conducted to validate the sediment classification model and undrained shear strength models. Field vane shear tests at the location of the probe drops were used to …
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The Analysis of Weak Rock Using the Pressuremeter
The pressuremeter is a versatile <italic>in situ</italic> testing instrument capable of testing a large range of materials from very soft clay to weak rock. Due to limitations of other testing devices, the pressuremeter is one of the few instruments capable of capturing stiffness and strength …
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Expanding options for the mechanical characterization of biological materials
… and sample preparation. Volume Controlled Cavity Expansion (VCCE) is a recently developed technique to measure local mechanical properties of soft materials in their natural environment. Through the highly controlled expansion of a fluid bubble at the tip of an injection needle, paired with …
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Deformation mechanisms beneath shallow foundations
… mechanism as the basis of an ellipsoidal cavity expansion model. An upper-bound energy approach was used to determine the load-settlement behaviour of circular shallow foundations on linear-elastic and non-linear clays, with yield defined using the von Mises' yield criterion. …
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Deformation and fracture of PMMA with application to nanofoaming and adhesive joints
… void growth model is developed to simulate cavity expansion during solid-state nanofoaming of PMMA by CO$_2$ in the first part of the thesis. To that end, tensile tests on two PMMA grades of markedly different molecular weight are conducted close to the glass transition temperature and over …
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Pore-water pressure accumulation under dynamic loadings
… is based on a limit pressure calculated using cavity expansion theory and a semi closed-form solution that is scaled to existing calibration chamber data using a chamber shape factor. This enables estimation of ψ directly from CPT results, which makes it practical and theoretically sound. This …