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 “"non-linear viscoelastic"”.
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Development of an Experimentally Validated Non-linear Viscoelastic Viscoplastic Model for a Novel Fuel Cell Membrane Material
… The uniaxial finite element model uses a non-linear viscoelastic viscoplastic (NLVE-VP) constitutive expression with parameters determined from uniaxial creep and recovery experiments at a single environmental condition. Validation tests show that this model accurately predicts results …
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Viscoelastic stress analysis of adhesively bonded joints
… version, SAAS3VP, was used for performing linear elastic and viscoelastic analyses on the single lap joint, and a non-linear viscoelastic analysis on the thick adherend specimen. Metlbond 1113 and Araldite adhesive properties were used in the linear elastic and viscoelastic analyses, …
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Investigation of strain rate sensitivity of polymer matrix composites
… and material loading type. The model is of a linear and non-linear viscoelastic type, depending on the type of loading and is applicable to a FRP plate undergoing out-of-plane stresses. This model incorporates techniques for approximating the quasi-static and dynamic response to general …
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Preparation and properties of micro- and nanocomposites based on high density polyethylene
… of filler dimensions was analyzed by comparing viscoelastic results for composites that contain micrometric copper particles (with an average diameter of 15 and 45 Î1⁄4m) and nanometric carbon blacks (with an average diameter of 15 and 30 nm). In general, these fillers substantially increase …
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Co-design of surface textures and non-newtonian fluids for decreased friction
Engineering design is typically limited to linear elastic solids or Newtonian fluids; however, design with more complex materials (for example non-linear viscoelastic materials) can provide ways to enhance performance. The main problems for design with non-linear viscoelastic materials are 1)~there …
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Parametric impact characterisation of a solid sports ball, WITH a view to developing a standard core for the GAA Sliotar
… dynamic impact behaviour of the sliotar core. Viscoelastic characterisation of the balls was conducted for a range of impact speeds. Modern polymer balls exhibited strain and strain-rate sensitivity while traditional multi-compositional balls exhibited strain dependency. The non-linear …
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Mechanical Modelling of single and collective cells behavior
… have suggested important direct implications of viscoelasticity of human cells and cell cytoskeleton dynamics on some relevant collective and at single-cell behaviors such as migration, adhesion, and morphogenesis. Other experimental studies have been performed on individual cancer and healthy …
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A Non-linear Visco-elastic Model for Dynamic Finite Element Simulation of Bovine Cortical Bone
… 4, 5, 6]. The behaviour can be captured using non-linear viscoelastic models. This dissertation focuses on the development and implementation of a material model of cortical bone based on non-linear visco-elastic models to capture the intermediate strain rate regime behaviour. The material …
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The use of a novel residuum model to design a variable-impedance transtibial prosthetic socket
… to model identification procedures that employ non patient-specific and incomplete data sets, today's finite element (FE) models of the residuum are not predictive, leading to suboptimal socket designs. As such, there exists a need for a comprehensive biomechanical model of the residuum for the …
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Compression Creep Rupture of an E-glass/Vinyl Ester Composite Subjected to Combined Mechanical and Fire Loading Conditions
… glass transition where failure is controlled by viscoelastic effects. Given the importance of compression loading to a structure subject to fire exposure, the goals of this work are succinctly stated as the:(a)Characterization of the non-linear viscoelastic and viscoplastic response of the …
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Characterization of a Viscoelastic Response from Thin Metal Films Deposited on Silicon for Microsystem Applications
… to the actuating force. A fully recoverable non-linear viscoelastic response has been observed in electrostatically driven micro actuators employing torsional hinges of silicon covered with thin metal films. The viscoelastic response occurs over a time period of 50 minutes at an operating …
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Fabrication and Characterization of Torsional Micro-Hinge Structures
… actuators observe to have a fully recoverable non-linear viscoelastic response. The device consists of a micro-hinge which is suspended by two hinges that sits inside a micro machined well. To achieve a specific angle of rotation when actuated, the mechanical forces need to be characterized …
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Finite element modelling the forming of components for portable electronic devices
… controlled bulge testing experiments revealed non-linear strain paths in principal directions yielding average and maximum strain rate ranges of 2.5–5 s-1 and 5–18 s-1 respectively, across the forming temperature range of 130–155 ⁰C. Extensive in-plane biaxial testing used to uncover the …
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Understanding the effect of nanofillers on the properties of polypropylene and glass fiber/polypropylene multiscale composites
… regions located at the filler surface. The non-linear viscoelastic creep of the composites, successfully studied by the application of the time strain superposition principle (TSSP), showed a considerable enhancement of the creep stability in nanocomposites with respect to unfilled PP, …
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Time dependent mechanical behavior of mammalian collagen fibrils
… been studied extensively and was shown to follow non-linear viscoelasticity, as similar quantitative understanding of the time-dependent deformation of individual collagen fibrils is missing, albeit essential for our understanding of the dissipative processes occurring in tissues and the …