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Showing 1 to 20 of 24 for “"deviatoric stress"”.
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Contributions to the Study of Lithospheric Deformation and Seismicity in Stable Continental Regions
… with each other? How well do they correlate with stresses and geological proxies for rheological variation? The ultimate goal of this study was to better understand stable continental regions like southern Africa, where large earthquakes occur despite not being near plate boundaries, for example …
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High Deviatoric Strain Engineering/
… (ISE). In this thesis, we study ESE and ISE by deviatoric (nonhydrostatic) strain. For ESE, we model how imposition of slowly-varying inhomogeneous elastic strain can induce the electronic structure changes of semiconductor crystals. The strain-dependent shift of valence and conduction band …
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Adapting The Modified Cam Clay Constitutive Model To The Computational Analysis Of Dense Granular Soils
… of dense sands to analyze the accuracy of the stress-strain behavior. This analysis is based on triaxial test data applied to remolded and compacted sand samples under drained conditions. The laboratory triaxial tests were performed by the Florida Department of Transportation to research the …
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Crustal heterogeneities and complexities of fault processes
… elastic medium in a transform domain with a deviatoric stress field imposed at remote distances (compressive NE − SW, tensile NW − SE). An isotropic compressive stress component is induced outside the asperity, in the direction of the compressive stress axis, and a tensile component in the …
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Subcritical time-dependent response of Berea sandstone
… construction and storage activities introduce stress disturbances within the subsurface layers. The response of rocks to these disturbances unfolds over extended periods, sometimes spanning months to years, giving rise to time-dependent deformation. Laboratory- and field-scale observations …
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Comparison and Correction of Multistage Triaxial Tests to Single Stage Triaxial Test for the Rock Mechanical Testing
… Triaxial (SST) is where a constant confining stress is applied and the axial stress is raised until the sample fails. This is compared to the Multistage Triaxial (MST) test, where the sample is loaded to the point of positive dilatency (PPD) then unloaded to low deviatoric stress, the …
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Equivalent plastic strain for the Hill's yield criterion under general three-dimensional loading
… of the equivalent plastic strain for plane stress in matrix notation is presented using associated plastic flow and work conjugation. A similar method is attempted for the general three-dimensional case; however, a singularity appears as the six components of the strain increment vector are …
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An anisotropic damage model for rock
… friction law, which excludes damage at low deviatoric stress levels. The formulation of the directional damage extends the arguments of continuum damage models for tension cracking to general, tension and compression, stress states. This is achieved by the definition of damage in a subdomain …
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The ramifications of diffusive volume transport in classical fluid mechanics
… unit volume in the fluid which requires that the deviatoric stress tensor be expressed in terms of the volume velocity. Furthermore, an expression for the diffusive flux of internal energy is derived that differs from classical results by a term proportional to the diffusive flux of volume. This …
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Effect of loading history in necking and fracture
The effect of Lode angle parameter, or the third deviatoric stress invariant, on plasticity and fracture is studied using flat-grooved transverse plane strain specimens. A generalized asymmetric plasticity model for isotropic materials with both pressure and Lode angle dependence is developed. …
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Constitutive relationships for agricultural soils
… 17.2, 24.1, 34.4 and 41.4 kPa. Plots for deviatoric stress and axial strain were found to be bilinear. Initial and latter portions of the curve were assumed to represent the elastic and plastic deformations of the sample, respectively. Assuming an associated flow rule, an elastic-plastic …
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Shear and consolidation behavior of slurry-deposited, desiccated tailings and compacted filtered tailings
… considering similar initial conditions (e.g., stress and density). The increase in undrained shear strength was attributed to the tailings fabric, which generated a stiffer response to loading and transitional behavior from contractive to dilative tendencies when sheared undrained. Consolidated …
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An experimental investigation of the creep behavior of an underground coalmine roof with shale formation
… disturbs the natural equilibrium of the in-situ stresses in the surrounding rock. Because of the opening, the surrounding stratum deforms to fill the opening and return to the pre-mining stress state. Such deformation, if allowed to continue, will lead to failure of the strata, which creates an …
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Structural Optimization of Regeneratively Cooled Rotating Detonation Rocket Engines
… geometries which minimize thermomechanical stresses that might drive such failures. The analysis considers thermal stresses from temperature gradients through the combustor wall, bending stresses due to cooling channel pressurization, and dynamic stresses from detonative loading. To …
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An experimental study on time-dependent behaviour of reconstituted clayey soils in 1D and triaxial compression
… is to experimentally investigate the role of stress history, soil properties and loading system in the time-dependent strength-deformation behaviour of reconstituted clayey soils. The experimental program consists of oedometer and triaxial compression tests on compacted lightly …
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Use of computational fluid dynamics in the design of bubble column reactors
… models (laminar, k-e turbulence and the Reynolds stresses). mThis investigation raised many questions about how gas-liquid interactions are captured numerically. To answer some of these questions the analogy between thermal convection in a cavity and gas-liquid flow in bubble columns was invoked. …
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Experimental and numerical study on the effect of strain rate to ductile damage
… are often only validated in a limited region of stress states, for example tensile failure by void growth but not shear. In addition, the predictions generally do not include strain rate or temperature effects. Quasistatic tests are often used in calibration, even though many applications such as …
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The Mechanics of Active Faulting and Mountain Building
… earthquakes. I use numerical calculations of stress-driven afterslip to show that, in order to account for the limited postseismic afterslip at Bam, most of the fault zone must remain frictionally locked. I also find that, to explain the postseismic InSAR measurements and the long-term growth …
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Assessment of Improvement in Unpaved Roadway Performance Using 3D Geogrids Under Cyclic Loading
… 41 kPa to 55 psi (6 psi to 8 psi of confining stress and deviatoric stress from 13.7 kPa to 124 kPa (2 psi to 18 psi). The used frequency of the load cycles was 1 Hz or one per 1 second, where the maximum applied stress occurred in the first 0.2 seconds of the loading cycle, while the contact …
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Small strain stiffness of fine grained soils
… in two computer controlled hydraulic stress path cells so that it was possible to measure the very small strain stiffness of the soil at' any stage of a triaxial stress path test and compare it directly to shear nioduli obtained at larger strain levels. The electronics required to run …
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