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 49 for “"Stress-strain curve"”.
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Experimental Characterization of Heterogeneous Deformation Due to Phase Transformations, Twinning, and Slip Deformation Using Digital Image Correlation
… the transformation sequence, nuances of the stress-strain curve such as strain hardening and softening, the hysteretic behavior, the strain-rate dependence, twinning strain, twin-twin intersections, twin fraction evolution, dynamic strain aging, grain interactions, mesoscopic slip bands, and …
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Complete stress-strain characteristics of high performance concrete
… The ductility can be found from the behavior of stress-strain curve, therefore, a well-defined stress-strain curve can be used to understand its ductility and other mechanical behavior. In this research, a series of compression tests are conducted. Silica fume has been used to get high …
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Compressive crippling of structural sections
… presented for the calculation of the crippling stress of structural sections as a function of material properties and the proportions of the section. The presence of formed or anisotropic material is accounted for by the use of an effective stress-strain curve in defining the material …
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Mechanical Investigation of Damage in Ligaments
… in the toe region of the tensile axial stress-strain curve. Straight collagen fibers behave as a linear elastic material. The gradual damage of collagen fibers determines the nonlinearity in the failure region of the tensile axial stress-strain curve. The parameters in the constitutive …
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Uniaxial and triaxial behavior of high strength concrete with and without steel fibers
… study mainly focuses on the octahedral shear stress strain relationship of those two types of concrete, which is adopted as the basis to develop a new incremental constitutive model. Emphasis is also put on the investigation of the variation of tangent Poisson's ratio under not only uniaxial …
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Nonlinear analysis of plane frames
… and Robinson [6] within the linear range of the stress-strain curve. When the displacements become large, the Gurfinkel and Robinson routine tends to give higher estimates of the strain state of the section being analysed as compared to the results via the finite element model. Changing the …
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Investigations into the Form and Design of an Elbow Exoskeleton Using Additive Manufacturing
… The experiments on TPU kerf cut found that the stress-strain curve of the sample can be modified by changing the cut pattern, it is even possible to control the linear region. The TPU TPMS test showed that given the same volume, changing the lattice parameters can result in different bending …
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Using shape memory alloy as dampers : design methodology
… friction element, the lambda box, to model the stress-strain curve of SMA during pseudoelasticity. Simulation is carried out to study the dynamic response of such a system under harmonic loading. Three kinds of systems were examined, in order of increasing complexity: the friction damper system, …
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Experimental study of ductile fracture of tubes under combined tension/torsion
… was first executed to determine the correct stress-strain curve for 1045 steel. A torsion specimen was designed based on the constraints of the testing machine, and the torsion test was carried out. A model of the specimen was constructed in ABAQUS using the results of the tension simulation, …
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Dahl friction modeling
… theory proposed that friction behaved as a stress acting upon the quantum mechanical bonds at the interface. Thus, the relationship between frictional force and position would be analogous to a stress-strain curve, complete with hysteresis should there be permanent displacement akin to …
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A detailed design analysis of a lumenally delivered, flexible, balloon-assisted, sterile endoscopic overtube.
… the only material properties for the entire stress-strain curve known to the literature to be accurate. A series of tests were conducted on several different freshly donated organs. Statistical analyses were performed comparing the inner and outer layers, and the 0° and 90° orientation. These …
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Improvements in digital image correlation and application in material mechanical test
… experimental method to determine the true stress-strain curve is proposed. The instantaneous cross-section area is estimated by only one camera in aid of DIC method. The derived true stress-strain curves and mechanical parameters of metal material Al6061 and CP-Ti from miniature specimens …
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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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Quantification of the Elastic and Relaxation Properties of Human Tunica Albuginea under Biaxial Loading
… a fixed displacement for 30 minutes to allow for stress relaxation. The loading and relaxation were then repeated for a second time. Stiffness, Young's Modulus, strain at inflection point between the toe region and linear region on the stress-strain curve, as well as percent stress relaxation …
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Investigation into the Effects of Wire Mesh on Tensile and Impact Properties of Fiber Metal Laminates
… Testing System for impact tests. Samples were strained at arate of 2 mrn/min for tensile tests and impacted with enetgies of 10 to 40 J in l0 J increments for impact tests. It was found that the 6.67 N Q4 oz) ShieldStand <sup>®</sup> S with 2024-T3 aluminum alloy sheet samples performed best …
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Methodology to determine post yield material mechanical properties from spherical indentation
… this research, a method of determining material stress-strain curve based on spherical indentation is studied. Spherical-indentation process is analyzed by finite element (FE) method and a systematic analysis of relationships between indentation parameters and true stress/plastic-strain (sigmat- …
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Ductile fracture after complex loading histories : experimental investigation and constitutive modeling
… practice, sheet metal often fails after complex strain paths that deviate substantially from the widely studied proportional loading paths. Different from previous works on the ductile fracture of sheet metal, this thesis research addresses the experimental and modeling issues related to the …
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Multiaxial fatigue damage model for random amplitude loading histories
… loading is proposed in this study. A normal strain based analysis incorporating the multiaxial state of stress is conducted along a critical orientation assuming a constant strain ratio. The dominant deformation direction is chosen to be the critical orientation which is selected with the …
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Prediction of erosion in cementitious materials subject to high thermal and pressure loading
… distributions were expressed in terms of thermal stress using firstly an elastic constant to failure and secondly an elastic-plastic model based on the stress-strain curve of concrete. The results produced by the respective models were then compared with experimental data of time to onset failure. …
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Design of Lightweight Magnesium Alloys: Processing, Microstructure and Properties
… compression has a unique, twinning region of the stress-strain curve. This asymmetry is unreliable/ undesirable in practical applications. This twinning is caused by lack of slip systems in magnesium that can accommodate deformation. Further limitations of magnesium include its limited ductility, …
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