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Showing 1 to 20 of 189 for “"Stress relaxation"”.
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Stress relaxation of Zircaloy-4.
Thesis. 1976. B.S.--Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.
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Stress Relaxation of AA 5182 During Hot Deformation
… the deformation process under relatively low stress and a much lower strain rate. For AA 5182 deforming at these temperatures and strain rates, there are two distinct deformation mechanisms. The first is a high temperature and low strain rate diffusion regime termed solute drag (SD) which is …
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Stress relaxation of AZ31 alloy using high energy diffraction microscopy
… spots during a loading increment and subsequent relaxation. The study was conducted at the Advanced Photon Source (APS) sector 1-ID-C at Argonne National Laboratory and loading steps and relaxation were set at different points within elasto-plastic transitions (118MPa, 135MPa, 153MPa and 168MPa). …
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Ion-induced stress relaxation during the growth of cubic boron nitride thin films
… films by magnetron sputtering under simultaneous stress relaxation by ion implantation. An in situ instrument based on laser deflectometry on cantilever structures and in situ ellipsometry, was used for in situ stress measurements. The characteristic evolution of the instantaneous stress during …
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An Assessment of in-Service Stress Relaxation of a Work-Hardened Aluminum-Magnesium Alloy
The bent beam relaxation test---a simple method to measure relaxation at stress levels well below the usual 0.2% offset yield stress, is outlined first, and the method to analyze the experimental results is also discussed. Several constitutive models are applied to fit the experimental results, …
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Modeling of diffusional creep and stress relaxation in copper grains during manufacturing of microelectronic integrated circuits
… was developed to study diffusional creep and stress relaxation in Cu grains with several atomic monolayers thick grain boundary region of enhanced diffusivity. The model was motivated by the need to study nanoscale back-end interconnect structures of microelectronic circuits. These structures …
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Cartilage stress relaxation induced by intra-tissue transport of cationic nanoparticles : implications for post-traumatic osteoarthritis drug delivery
… Using cartilage explants in vitro, mechanical stress relaxation experiments were performed at two ionic strengths (low = 0.015 M NaCl and physiologic = 0.15 M NaCl) in the presence and absence of added avidin. After an initial set of compressive strain ramps and relaxations, 100 [mu]M avidin …
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Nonlinear Viscoelastic Behavior of Ligaments and Tendons: Models and Experiments
… ligaments and tendons was investigated. Axial stress-stretch data and stress relaxation data at different axial stretches were collected by testing rat tail tendon fascicles. The experimental results demonstrated, for the first time, that the shape of the normalized axial stress relaxation …
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Relaxation of prestressed steel used in construction of the confederation bridge
Relaxation is one of the main sources of time-dependent stress losses in prestressed concrete construction. In the present study, an experimental investigation of the stress relaxation of the prestressing steel used in construction of the Confederation Bridge is undertaken. Relaxation is measured …
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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 …
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Time dependent mechanical behavior of mammalian collagen fibrils
… by separating the effects of macroscopic stress and strain. In the context of the second objective, the validity of linear viscoelasticity and the applicability of non-linear viscoelasticity models previously developed for collagenous tissues, were investigated for partially and fully …
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Viscoelastic Models for Ligaments and Tendons
… time, or creep, when subjected to a constant stress and a slow continuous decrease in stress over time, or stress relaxation, when subjected to a constant strain. Moreover, the loading and unloading stress-strain curves are different when the tissues are subjected to cyclic loading, showing …
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Early Age Stresses and Creep-Shrinkage Interaction of Restrained Concrete
The analysis revealed stress-induced shrinkage as a major mechanism of drying creep for plain and fiber reinforced concrete (FRC). Microcracking forms a significant portion of drying creep of plain concrete, but it is less significant in FRC. Therefore, creep of FRC is dominated by real mechanisms, …
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Viscoelastic characterization of collagen-GAG scaffolds
… collagen-GAG scaffolds in order to develop a stress-strain curve. Strains that fell in the linear elastic region of these curves were selected and then used in stress relaxation tests that were also performed on dry and hydrated specimens. The relaxation modulus was calculated from the …
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Evaluation of breadmaking quality from common wheat quality parameters and fundamental rheological, chemical, and functional properties of wheat cultivars
The stress relaxation and deformability modulus of wheat doughs made from five groups of wheat cultivars of differing breadmaking ability were determined. Doughs made from poor breadmaking cultivars had greater rates of stress relaxation than doughs made from good breadmaking cultivars. Doughs made …
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