Modeling dynamic recrystallization of olivine aggregates deformed in simple shear

High shear strain of olivine aggregates: rheological and seismic consequences.

High-pressure and high-temperature torsion experiments on olivine aggregates in dislocation creep show about 15 to 20% strain weakening before steady-state behavior, characterized by subgrain-rotation recrystallization and a strong lattice preferred orientation. Such weakening may provide a way to focus flow in the upper mantle without a change in deformation mechanism. Flow laws derived from l...

Textures in experimentally deformed olivine aggregates: the effects of added water and melt

The texture development in experimentally sheared aggregates of olivine was monitored as a function of increased water content and added melt. In dry samples, an alignment of {010} with the shear plane and <100> and <001> with the shear direction, respectively, was observed, consistent with intracrystalline glide on the (010)[100] and (010)[001] slip systems. Samples with high water content sho...

FIRST Ti-XANES ANALYSES OF OLIVINE IN AMOEBOID OLIVINE AGGREGATES

Strength Deterioration of Nonfractal Particle Aggregates in Simple Shear Flow.

The restructuring of a nonfractal particle aggregate in simple shear flow was simulated by a Stokesian dynamics approach. We studied the deformation and the resultant strength change of aggregates by the surrounding flow under the condition that the cohesive strength of an aggregate is comparable to the fluid stress. In particular, we focused on how the aggregate deteriorates because of the flu...

Dynamic recrystallization as a potential cause for adiabatic shear failure.

Dynamic recrystallization (DRX) is almost universally observed in the microstructure of adiabatic shear bands. It is usually admitted that DRX results from the large temperatures that develop in the band along with very high local strains. This paper reports the observation of dynamically recrystallized nanograins in Ti6Al4V alloy specimens that were impact loaded to only half the failure strai...