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 58 for “"Principal Stress"”.
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Principal stress line computation for discrete topology design
Principal stress-lines are pairs of orthogonal curves that indicate trajectories of internal forces. Subsequently, these curves idealize paths of material continuity, and naturally encode the optimal topology for any structure for a given set of boundary conditions. Stress-line analysis has the …
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An Investigation of Perceived Principal Stress and Its Impact on Principals in Southwest Georgia
… to determine to what extent southwest Georgia principals perceive they are stressed, identify principal stressors and how the stressors impact the principals’ work. Principals are leaders of school building who are experiencing increased stress. Therefore; it is important to understand what …
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Experimental check of Grossers method for finding the sum of the principal stress inside a photoelastic model knowing the boundary conditions
Thesis: B.S., Massachusetts Institute of Technology, Department of Mechanical Engineering, 1944
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Y-cracking in continuously reinforced concrete pavements
… in CRCPs. When the direction of maximum principal stress changes, it could cause a change in the crack direction, potentially forming a Y-crack. Finite Element Models (FEMs) were run to model the change in principal stress direction based on design and construction conditions. The finite …
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Effect of Material and Geometric Parameters on Deformations of a Dynamically loaded Prenotched Plate
… length of the projectile on the maximum tensile principal stress and the initiation and propagation of shear bands at the notch-tip is analyzed. It is found that for high impact speeds or enhanced thermal softening, two shear bands, one at and the other at to it propagate from the notch tip. …
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Topology Optimization Using Load Path and Homogenization
… load, their partial derivatives related to stress tensor, and satisfying equilibrium. In the presence of a body load the stress tensor can be decomposed into solenoidal and irrotational fields using Gurtin or Helmholtz decomposition. The load path is calculated using the solenoidal field. A …
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Rapid Drawdown Analysis using the Finite Element Method
… strengths based on effective consolidation stresses from finite element analysis and the results of isotropically consolidated undrained triaxial compression (ICU-TC) tests. The field strengths appropriate for use with this rapid drawdown method were found to be on average 70% of the …
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Modeling the dynamics and stresses of elongated particles in vertical axis mixers
… focuses on modeling and analysis of dynamics and stresses of elongated particles processed in vertical axis mixers. Elongated particles are of particular interest in the operation of pharmaceutical AFDs since the particles processed in such devices are often needle-shaped.^ A discrete element …
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Fatigue limit analysis involving biaxial stress components
Biaxial stress fatigue data is carefully examined in order to determine how much foundation exists for a rational approach to classical stress-based fatigue limit analysis involving biaxial stress components. A review is given of the methods presently in vogue, and new methods are suggested for …
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Pore Pressure Parameters and Cyclic Resistance Under Generalized Loading
… the effects of the magnitude and nature of principal stress rotation on the cyclic resistance of sands. Test results over a range of α_σc and 〖∆α〗_σ indicate that that the weakest cyclic resistance at a given initial α_σc always correspond to 45° stress rotation, and for a given magnitude of …
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Cenozoic Tectonic Evolution of the Eastern Cordillera and Adjacent Basins
… slip, seismic reflection data, and a variety of stress indicators (including borehole breakouts, natural fractures, and earthquake focal mechanism solutions) suggest that the Eastern Cordillera region in Colombia is an active zone of deformation that has undergone various stages of deformation. …
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Stress study in faulted tunnel models by combined photoelastic measurements and finite element analysis
… to develop a proper technique for analyzing the stresses in and around three adjacent scaled tunnel models, along with the stress concentration factors resulting from the existence of a fault that penetrates two of the three tunnels, at an inclined angle; Photoelasticity and Finite Element …
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EFFECT OF WELD-TOE GRINDING ON FATIGUE LIFE BASED ON THEORY OF CRITICAL DISTANCE
… geometries and notches to evaluate the fatigue stresses in real welded components. With the adoption of the theory of critical distance, the calculated stress is closer to the maximum principal stress of the weld toe determined by the finite element analysis, compared with the nominal stress and …
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Thermomechanical Stress in Solar Cells and Modules: A Finite Element Modelling and Experimental Investigation
… which can be attributed to thermomechanical stress induced during the fabrication process. This thesis aims to deepen the understanding of the evolution of thermomechanical stress in Si cells and modules by utilising finite element modelling (FEM) complemented by experimental validations. …
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Evaluation of Tensile Bond Strength of Glass Ionomer Cements for Orthodontic Bonding
… to the bracket greatly affected the maximum principal stress developed in the adhesive layer. An increase in maximum principal stress of ≈1,000 MPa was seen when a true tensile debonding force (0° offset) was adjusted to 12° of offset. The results of this study indicate that Type II glass …
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Permanent Deformation Behavior of Airport Flexible Pavement Base and Subbase Courses
… following a wander pattern. Realistic pavement stresses induced by moving wheel loads were examined in the unbound aggregate base and subbase layers and the important effects of rotation of principal stress axes were indicated for a proper characterization of the permanent deformation behavior. …
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Ductile fracture modeling : theory, experimental investigation and numerical verification
… and Lode angle define a fracture envelope in the principal stress space. Plastic deformation induced damage is expressed by an integral of the damage rate measured at current loading and deformation status with respect to the fracture envelope. A non-linear damage rule is proposed to characterize …
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Stability of tunnels in water saturated shale under cyclic stresses: investigation on the coupling between mechanical and seepage characteristics
Under the coupled effect of water and cyclic stress, the mechanical properties of mine surrounding rock deteriorate, and its permeability changes, posing challenges to tunnel excavation support and mine stability control. The interaction between water infiltration into the rock mass and externally …
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Source Parameters and Tectonic Setting of the 2017 St. Elias Earthquake Sequence near the Southern Terminus of the Eastern Denali Fault, Northwestern Canada
… along two previously unmapped fault structures. Stress inversion indicates that the maximum principal stress axis is oriented almost perpendicular to the EDF, suggesting that the fault system is not well oriented for strike-slip in the contemporary stress field. Coulomb stress analysis indicates …
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Scale-model investigation of brittle tunnel failure using a true-triaxial device
… tunneling simulations, capturing unloading stress paths and face support behavior. Damage progression observation and post-mortem investigation provide detailed identification of damage mechanisms around the tunnel boundary, such as surficial spalling and damage zone development, as a …
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