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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 29 for “"Post-Yield"”.
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Methodology to determine post yield material mechanical properties from spherical indentation
… strain hardening properties, Young's modulus and yield strength. It is noticed that Tabor's empirical formula is valid in the plastic region (deep indentation) with a small percentage error in the calculated values of yield strength. Based on the FE results, strain values have been predicted …
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Improving Continuum Models for Excavations in Rockmasses Under High Stress Through an Enhanced Understanding of Post-Yield Dilatancy
… understanding of rockmass strength, it is the post-yield phenomenon of rock dilatancy which has remained the domain of greatest uncertainty in constitutive models. Particularly in the case of brittle rockmasses, where deformation is dominated by crack extension and dilation, the post-yield …
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The Effects of Strain Induced Softening on the Load Carrying Capability of Components
… its initial strength in a few hundred cycles at post yield strain ranges. In most practical instances, though, significant stress reversals in components only occur in localized regions, suggesting that the use of the enhanced strength characteristics would be acceptable.
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Laboratory Investigation of Shear Behaviour in Rock Joints Under Varying Boundary Conditions
… dilation angle is created to characterize the post-yield behaviour of rock joints to be used an input to account for post-yield behaviour in numerical models. Measured geomechanical properties (fractures and intact rock) were then used to complete a preliminary numerical modelling program of …
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Biomechanical Comparison of Wire Circlage and Rigid Plate Fixation for Median Sternotomy Closure in Human Cadaver Specimens
… The purpose of this study was to compare the yield load, construct stiffness, ultimate load, displacement at ultimate load, and post-yield behavior of three sternotomy closure methods (Peristernal wires or Sternalock titanium plates) when stressed in each of three directions: lateral …
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Parameters Influencing Seismic Structural Collapse with Emphasis on Vertical Accelerations and the Possible Related Risks for New and Existing Structures in the Central and Eastern United States
… the SDOF models — the lateral stiffness, the post-yield stiffness ratio, the yield strength, and the stability ratio (P-Delta effects). Then, three parameters were associated with the ground motions — the records themselves, the lateral ground motion scales, and the vertical ground motion …
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Effect of Viscous Fluid Dampers on Steel Moment Frame Designed for Strength and Hybrid Steel Moment Frame Design
… Frame, the earlier the pushover curve starts yielding and the later the negative post yield stiffness of the pushover curve was reached. It was observed that the effect of early plastic hinge forming in the frame, which caused inelastic hysteretic damping, and the relatively late formation of …
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The role of molecular length scale on the viscoplastic response of amorphous polymer nanofibers in the glassy state
… at room temperature have demonstrated shear yielding and large deformations that are not possible at the macroscale where PS fails at small strains due to crazing. This dissertation research focused on direct experiments with atactic PS nanofibers to elucidate and quantify the unusual …
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Seismic Response of Short Period Structures and the Development of a Self-Centering Truss Moment Frame with Energy Dissipating Elements for Improved Performance
… using an elastic-linear hardening model with post-yield stiffness ranging between -10% and +10% of the initial stiffness. This part of the study was done to gain a general understanding of the influence of natural period and post-yield behavior on the collapse performance of structural systems …
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A Study of the Seismic Performance of Early Multi-Story Steel Frame Structures with Unreinforced Masonry Infill
… damage in all seismic risk regions, including post-yield damage of the structure, although in low risk regions that damage is confined entirely to the infill walls. Practicing structural engineers should be aware that in all seismic risk zones existing steel frame buildings with unreinforced …
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New Herbicide Strategies for Weed Management in Pumpkin and Soybean and Potato Vine Desiccation
… (14 days after treatment), skin set, and yield were noted amongst treatments. Residual herbicides are routinely used for weed control in pumpkin. Fluridone and acetochlor formulations applied preemergence were evaluated in direct-seeded pumpkin compared to other labeled herbicides. …
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Using Pulse R -Factors to Estimate Structural Response to Earthquake Ground Motions
… of short period systems having positive post-yield stiffness and long period elasto-plastic systems are reported. The equal energy rule is found to be applicable to only a limited set of pulse shapes. The response of 4- and 12-story moment-resistant frame buildings subjected to the 15 …
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Computational modeling of trabecular bone in lower extremity injuries due to impact
… capture the resulting material softening in the post-yield stress-strain response.
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Bond and Material Properties of Grade 270 and Grade 300 Prestressing Strands
… was used to determine modulus of elasticity, yield stress, ultimate stress, and ultimate elongation for each strand. The yield stresses and ultimate stresses for many of the strands did not meet the requirements found in ASTM A416. The ultimate elongation results far exceeded the requirements …
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Morphologie und Bruchverhalten von Block- und Multipfropfcopolymeren
… (EWF-) Methode, welche als Konzept der „Post-Yield“-Bruchmechanik innerhalb der Fließbruchmechanik für duktile nanostrukturierte polymere Materialien sehr gut anwendbar ist und Aussagen zur Bruchzähigkeit der Materialien liefert. Zur näheren Charakterisierung des zeitaufgelösten …
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ΔΙΕΡΕΥΝΗΣΗ ΤΗΣ ΑΝΕΛΑΣΤΙΚΗΣ ΣΕΙΣΜΙΚΗΣ ΣΥΜΠΕΡΙΦΟΡΑΣ ΠΟΛΥΟΡΟΦΩΝ ΚΤΙΡΙΩΝ ΑΠΟ ΟΠΛΙΣΜΕΝΟ ΣΚΥΡΟΔΕΜΑ
… HYSTERETIC BEHAVIOUR OF R/C MEMBERS; AMONG THE POST-YIELD STIFFNESS PARAMETERS, THE ONE DETERMINING THE SLOPE OF THE UNLOADING BRANCH INTHE MODIFIED TAKEDA MODEL WAS FOUND TO HAVE THE LARGEST INFLUENCE ON THE RESULTS. REGARDING STAGE (B), THE MOST SERIOUS DEFFICIENCY FOUND IN THE SEISMIC …
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Plasticity and impact test studies on thermoplastic materials, finite element analysis and experimental correlation
… data input for the simulation software. Due to post yield uncertainties when measuring true values of stress and strain with conventional extensometric devices, an iterative approach was presented here as a solution for measuring large local plastic strains in tensile specimens. The experimental …
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Investigations of the Tissue Mechanical Properties and Susceptibility to Histotripsy-Induced Tissue Ablation for Intra-Abdominal Organs
… intestine, ducts, and vessels) elastic modulus, yield stress, yield strain, post-yield strain, energy to yield, and maximum stress and strain at yield. In general, histology analysis from the histotripsy experiments showed that there was an increase in tissue damage with increasing histotripsy …
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Yielding of unsaturated soil.
… models is the suggestion of the existence of a yield surface in mean net stress : deviator stress : suction space. Suction-controlled triaxial tests were performed to investigate the shape of the yield surface for unsaturated compacted speswhite kaolin with a particular stress history. The tests …
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Effect of Confinement and Temperature on the Behavior of EPS Geofoam
… increases in confinement lead to decrease in yield stress and post yield compressive resistances, depending on the EPS density and range of confining pressures. The practical significances of confining stress effects are discussed. An approach for incorporating the more significant effects of …
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