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Showing 1 to 18 of 18 for “"linear viscoelastic response"”.
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An Investigation of the Linear Viscoelastic Response of a Hypersonic Flight Vehicle
Made available in DSpace on 2014-12-09T18:12:25Z (GMT). No. of bitstreams: 1 6915323.pdf: 8311083 bytes, checksum: 3a81b1c4151c0c08d59e6a3b1ab9d958 (MD5) Previous issue date: 1969
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Prediction of Linear Viscoelastic Response of the Loss Shear Modulus of Polymer-Modified Binders
… to characterize the frequency dependence of response of polymer-modified asphalt binders. In an earlier study at Virginia Tech, mathematical models were developed to predict the storage and loss shear moduli of polymer-modified binders. However the model developed for the loss shear moduli is …
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Modeling of the linear viscoelastic response of polymer modified asphalt binders at intermediate and high temperatures
… ranging from 5 to 75° C. After establishing the linear viscoelastic range of response through performing stress sweeps, a series of frequency sweeps was carried out. Investigation of the resulting isothermal response curves indicated that simple time-temperature superposition is applicable, and …
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Effects of Storage on the Linear Viscoelastic Response of Polymer-Modified Asphalt at Intermediate to High Temperatures
… that significant changes affecting the dynamic response of binders occur during long term storage at a temperature of 23°C. These changes are dependent on the type and concentration of modifier and may be beneficial. Additionally, four mathematical models describing the dynamic response of …
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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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Relaxations in molecularly thin simple liquid films:linear viscoelasticity and non-linear response to shear
… relaxations of molecules under confinement, the linear and nonlinear response of molecularly thin simple liquid films confined between two solid surfaces were studied. The method was to measure the resistance to applied oscillatory shear deformation as a function of frequency and amplitude of …
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Free-radical maleation of poly(butylene adipate-co-terephthalate) in supercritical carbon dioxide and its effect on the percolation and deformation mechanism of layered silicate nanocomposites
… matrix was evident in the terminal region of the linear viscoelastic response under oscillatory shear, and a percolation threshold was determined to occur at 3.88% clay by weight. Transmission electron microscopy (TEM), x-ray diffraction (XRD), and the water vapor transmission rate (WVTR) were …
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Non-affine lattice dynamics of disordered solids
… Firstly, we discuss the static elastic response and the vibrational spectra of defective fcc crystals. The connection to different types of microstructural disorder in the form of bond-depletion and vacancies is described within the context of the inversion symmetry breaking of the local …
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Microscopic Theory of Linear Response in Amorphous Materials
… describe the various relaxation processes in the linear viscoelastic response of metallic glasses. In particular, to understand universal properties of relaxation, the VDOS obtained in simulations, or in experiments, is substituted into the model. The nonaffine contribution to elasticity is also …
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Characterization of a Viscoelastic Response from Thin Metal Films Deposited on Silicon for Microsystem Applications
… and reliability are critical. The material response to the stress developed within the hinge during actuation controls how the actuator will respond to the actuating force. A fully recoverable non-linear viscoelastic response has been observed in electrostatically driven micro actuators …
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Novel Rheometric Techniques and Constitutive Models for Linear and Nonlinear Rheology: Applications to Polymeric Solutions and Colloidal Gels
… the flow behavior, and modeling the constitutive response of these complex fluids is important for predicting time-varying material performance under various processing conditions, thus helping prevent failures in large-scale industrial operations. However, modeling the rheological behavior of …
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Fabrication and Characterization of Torsional Micro-Hinge Structures
… 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 with a …
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Nonlinear dynamics of complex fluids in fragmentation and fracture
… or biological macromolecules that result in viscoelastic fluid characteristics. For many of these processes the effects of varying the rheological properties on the dynamics of fragmentation or fracture are still poorly understood. In this thesis, we investigate some of the underlying …
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The rheology and structure of thermotropic liquid crystalline polymers in extensional flow
… of the LCPs was determined and found to follow linear viscoelastic response at very low strains and then shows mild strain hardening with increasing strain, which is qualitatively similar to the behavior of certain linear polyolefins such as PS and HDPE. From the elongational viscosity behavior …
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The Effect of Composition on the Linear and Nonlinear Mechanical Properties of Particulate Filled Elastomers
… elastomers, a complete understanding of their linear viscoelastic properties and the nonlinear mechanical properties, including stress softening (Mullins), strain dependent dynamic modulus (Payne) and others remains elusive. Furthermore, studies on filled elastomers have failed to produce a …
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Time dependent mechanical behavior of mammalian collagen fibrils
… 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 development …
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Micro- and macro-rheological studies of the structure and association dynamics of biopolymer gels
… micron-sized particles are not predictive of the linear viscoelastic response of mucin gels. However, when taken together, the results from both techniques help to provide complementary insight into the structure of the network. For instance, we show that macroscopic stiffening of mucin gels can …
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Polymer Structure and Dynamics in Nano-Confinements: Polymer Nanocomposiets and Cylindrical Confinement
… NPs. This finding suggests that the mechanical response of silica NPs contributes to the linear viscoelastic response. The impacts of nanoconfinement imposed by impenetrable planar or cylindrical walls were investigated by molecular dynamics simulations and experiments. The polymer conformation …