This study investigates an application of genetic programming (GP) for modeling of coarse rotund sand– mica mixtures. An empirical model equation is developed by means of GP technique. The experimental database used for GP modeling is based on a laboratory study of the properties of saturated coarse rotund sand and mica mixtures with various mix ratios under a 100 kPa effective stresses, becaus...

When mechanical constraints are present, solid-state reactions often induce deviatoric inelastic strains in addition to volume change. Existing models either attribute such deformation to the plastic flow driven by the stress exceeding a non-measurable kinetic-dependent yield strength, or need to introduce a deviatoric-stress-dependent chemical potential. By employing the transformation strain ...

Si is a promising anode material for Li-ion batteries, since it absorbs large amounts of Li. However, insertion of Li leads to 334% of volumetric expansion, huge stresses, and fracture; it can be suppressed by utilizing nanoscale anode structures. Continuum approaches to stress relaxation in LixSi, based on plasticity theory, are unrealistic, because the yield strength of LixSi is much higher t...

The question of extending limit analysis to materials with a non-associated flow rule is an old but important one. Many frictional soils, such as sands and drained clays, do not display the large volume change upon shearing that is predicted by an associated flow rule, thus calling into question the collapse loads that are found from the classical limit theorems. This question is important in p...

Dike emplacement in volcanic rift zones is often associated with the injection of “bladelike” dikes, which propagate long distances parallel to the rift, but frequently remain trapped at depth and erupt only near the tip of the dike. Over geologic time, this style of dike injection implies that a greater percentage of extension is accommodated by magma accretion at depth than near the surface. ...

We present a new, high spatial resolution image of stress orientation in southern California based on the inversion of earthquake focal mechanisms. We use this image to study the mechanics of faulting in the plate boundary region. The stress field contains significant spatial heterogeneity, which in some cases appears to be a result of the complexity of faulting and in other cases appears to be...

Introduction: An understanding of the sources of stress, and the expected style, orientation, and magnitudes of stress and associated strain is important for understanding the evolution of faulting on Mars and its relationship to loading, thus leading to an improved understanding of Martian geologic history and surface morphology. The Tharsis province, characterized by radial graben sets and ci...

[1] Spatially averaged, absolute deviatoric stress tensors along the faults ruptured during the 2002 Denali fault earthquake, both before and after the event, are derived, using a new method, from estimates of the orientations of the principal stresses and the stress change associated with the earthquake. Stresses are estimated in three regions along the Denali fault, one of which also includes...

A granular material is most likely to possess an initial anisotropic structure due to the depositional process or the previous stress history. There is also induced fabric anisotropy during shearing. Concerning the significant influence of fabric anisotropy on the stress-strain behaviour of a granular material, in-depth investigation on the two kinds of fabric anisotropy is essential. Initial f...

Generalized I lyushin ' s deviatoric stress and s t ra in spaces are introduced, which make it possible to apply directly the postulate of isotropy to initially isotropic materials with plastic properties influenced by the third deviatorie stress invariant and to a certain class of initially anisotropie materials. The generalizations proposed are connected with a new concept of description of p...