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 20 of 106 for “"viscoplastic"”.
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Continuity in Rigid Viscoplastic Flow
… equation for the rotation field in rigid viscoplasticity. The continuity condition provides a theoretical basis for assumptions of co-rotation models of crystal plasticity.
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Shear localization in viscoplastic solids
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1987.
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Direct numerical simulation of viscoplastic particulate flows
… overriding aspects to modelling suspensions in viscoplastic fluid flows. Firstly, for fully resolved particle suspensions---regardless of the carrier fluid---the discretisation scheme must cope with disparate length scales at the particle boundaries and wider flow field. In this work we adopt …
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Viscoplastic Study of 3D Printed Carbon Fiber Composites
… presented here involves an attempt to model the viscoplastic response of 3D printed carbon fiber composites made using the Mark Two 3D printer by Markforged. The ability to manufacture composites through the use of 3D printers is relatively new and contains gaps in the various mechanical …
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Flow of a Viscoplastic Material Past a Flat Surface
Made available in DSpace on 2014-12-12T00:25:57Z (GMT). No. of bitstreams: 1 7511857.pdf: 5501340 bytes, checksum: 08d3129a1579b83868cd982c86b4dd0b (MD5) Previous issue date: 1974
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Boundary element technique for in homogenous elasto-viscoplastic analysis, A
Includes bibliographical references.
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Large deformation of rigid-viscoplastic cantilevers subjected to impulsive loading
… is considered. The material is treated as rigid-viscoplastic; in this idealisation elastic effects are ignored, and the dependence of the yield stress on the rate of strain is taken into account. The problem is first analysed as one of impulsive loading, using the concepts of the mode …
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Enhancing Injectability and Viability of Cells using Viscoplastic Lubricated Flows
… enhancement in injectability. Here, we propose a viscoplastic lubricated gel co-flow, where the flow of the cell-laden payload through needles is facilitated by coaxial lubrication from a lower yield stress gel, to mitigate shear death, enhance injectability and enable stable flow. In this study, …
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A nonlinear viscoplastic double yield surface constitutive model for geologic materials
… approach is based on the framework of overstress viscoplastic theory and can be applied to any elastoplastic (inviscid) model.The most innovative idea of the proposed model is the identification of two components of strain for each deformation mechanism. In particular, in both the elastic and the …
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Cleaning viscoplastic soil layers from flat surfaces using impinging water jets
… walls of storage tanks and mixing vessels. Viscoplastic layers are common in a wide range of industrial applications and are challenging to clean due to their yield stress behaviour. When a stationary coherent turbulent perpendicular liquid jet impinges on a flat soiled surface, it generates …
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A new elasto-viscoplastic model for rate-dependent behavior of clays
… compression. This thesis develops a novel elasto-viscoplastic soil model, MIT-SR, to address these limitations. The proposed I-D formulation introduces a physically-based evolution law that attributes the macroscopic viscoplastic strain rate to an internal strain rate associated with the prior …
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The analysis of rigid-viscoplastic plane structures subjected to large impulsive loading
… ignored, and the material is considered as rigidviscoplastic in order to take rate effects into account. Computational advantage is obtained by modelling this behaviour by a homogeneous viscous constitutive relation, as the rigid phase is absent. As opposed to the standard displacement method …
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Physically based multiscale-viscoplastic model for metals and steel alloys: theory and computation
… therefore necessary to develop a rate-dependent (viscoplasticity) continuum theory bridging the gap between the classical continuum theories and the microstructure simulations. Physically based vicoplasticity models for different types of metals (body centered cubic, face centered cubic and …
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A Numerical Study of Intergranular and Oxidation-Driven Fracture in an Elastic-Viscoplastic Material
… oxidized grain boundary) embedded in an elastic-viscoplastic material. Additional studies illuminate the complex interactions between stress-assisted grain-boundary diffusion, inelastic material response and grain-boundary cleavage.
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A time integration procedure for elasto-viscoplastic constitutive equations of the internal variable type
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1985.
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The mechanics of shear-band formation in thermal viscoplastic materials at high rates of loading
The mechanics of adiabatic shear bands are investigated through the study of a one-dimensional simple shearing model. The materials considered are assumed to exhibit strain rate hardening, thermal softening, and strain hardening or softening. The mechanism leading to shear band formation is assumed …
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Micromechanics, macromechanics and constitutive modeling of the elasto-viscoplastic deformation of rubber-toughened glassy polymers
Glassy polymers, such as polystyrene (PS), poly(methyl methacrylate) (PMMA) and polycarbonate (PC), are common engineering polymers that have found uses in consumer products ranging from portable computers and optical lenses, to automotive components and appliance housings. PMMA and PS are …
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