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.
Results
Showing 1 to 9 of 9 for “"Load relaxation"”.
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Nonlinear Lumped-Parameter Model of the Lumbar Intervertebral Disc: A Study on Viscoelastic Deformation and Three-Dimensional Modeling of the Spine
… the motion of the IVD under axial cyclic loading and three-dimensional quasi-static loading as well as maintain computational efficiency for use in future musculoskeletal spine models. A viscoelastic standard nonlinear solid (SNS) model is introduced within this study. It was developed to …
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Viscoelastic behavior of water-blown flexible polyurethane foams
… foams. Three viscoelastic tests; tensile stress relaxation, compression load relaxation, and compression creep, were utilized to evaluate the behavior of these materials at constant temperature and/or relative humidity, RH. The tensile stress relaxation tests were performed at a 25 percent strain …
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The Effects of Early-Age Stress on the Elastic and Viscoelastic Behavior of Cement Paste
… response in cement paste beams using relaxation testing, with and without strain reversals in the load history. It was seen that strain reversal imparts significant changes in mechanical response, retarding load relaxation. Companion beams were tested for chemical composition at …
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Development and Execution of a Testing Strategy for Omnidirectional Wheels
… methods are described for characterizing the load relaxation, stiffness, and rolling resistance of omnidirectional wheels, and the results from these tests are presented. Test apparatuses for static loading and rolling resistance were created. Test results were analyzed to determine important …
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Mechanical behavior of tissue simulants and soft tissues under extreme loading conditions
… of hydrated soft tissues under dynamic contact-loading conditions. Given this motivation, this thesis studies the mechanical properties of compliant synthetic materials developed for tissue scaffold applications and of soft tissues, via modifying an established contact based technique for …
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Cryogenic penetration and relaxation behavior of dry and icy lunar regolith simulants
… content. We measured penetration resistance and load-relaxation behavior for both dry simulants under constant displacement rate penetration at pressures ranging from 1E-5 Torr to 700 Torr and at relative densities of ~20% and ~80%. Penetration resistance was sensitive to density and insensitive …
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Structural and viscoelastic studies of flexible polyurethane foams
… foams; the molded foams displayed higher load decay values in the viscoelastic measurements than slabstock foams. In an attempt to understand these dramatic differences, the two types of “cross-links" (covalent cross-links and urea based phase separated hard segment domains) were …
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Examining viscoelastic response of pregnant rat cervical tissue using 3, 4, and 5 element spring and dashpot models
… model that can be used for describing the stress relaxation phenomenon of the rat cervical tissue. The intention was to develop a successful model from linear springs and viscous dashpots without using a repetitive scheme. Same basic elements were supposed to be used only once to investigate how …
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Thermo-mechanical response and plastic deformation behavior of Hastelloy X at elevated temperatures — role of dynamic strain aging
… of Hastelloy X subjected to thermo-mechanical loading is investigated, and the phenomenon of dynamic strain aging is studied under isothermal and temperature jump experiments, using the technique of digital image correlation (DIC). The material of interest, a Ni-based superalloy, is widely used …