Skip to Main content Skip to Navigation
Journal articles

Modeling the effect of subgrain rotation recrystallization on the evolution of olivine crystal preferred orientations in simple shear

Abstract : Homogenization models are widely used to predict the evolution of texture (crystal preferred orientations) and resulting anisotropy of physical properties in metals, rocks, and ice. They fail, however, in predicting two main features of texture evolution in simple shear (the dominant deformation regime on Earth) for highly anisotropic crystals, like olivine: (1) the fast rotation of the CPO towards a stable position characterized by parallelism of the dominant slip system and the macroscopic shear and (2) the asymptotical evolution towards a constant intensity. To better predict CPO-induced anisotropy in the mantle, but limiting computational costs and use of poorly-constrained physical parameters, we modified a viscoplastic self-consistent code to simulate the effects of subgrain rotation recrystallization. To each crystal is associated a finite number of fragments (possible subgrains). Formation of a subgrain corresponds to introduction of a disorientation (relative to the parent) and resetting of the fragment strain and internal energy. The probability of formation of a subgrain is controlled by comparison between the local internal energy and the average value in the polycrystal. A two-level mechanical interaction scheme is applied for simulating the intracrystalline strain heterogeneity allowed by the formation of low-angle grain boundaries. Within a crystal, interactions between subgrains follow a constant stress scheme. The interactions between grains are simulated by a tangent viscoplastic self-consistent approach. This two-level approach better reproduces the evolution of olivine CPO in simple shear in experiments and nature. It also predicts a marked weakening at low shear strains, consistently with experimental data.
Document type :
Journal articles
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-01243503
Contributor : Gm Aigle Connect in order to contact the contributor
Submitted on : Tuesday, December 15, 2015 - 9:11:09 AM
Last modification on : Monday, October 25, 2021 - 11:38:17 AM

Identifiers

Collections

Citation

Javier Signorelli, Andrea Tommasi. Modeling the effect of subgrain rotation recrystallization on the evolution of olivine crystal preferred orientations in simple shear. Earth and Planetary Science Letters, Elsevier, 2015, 430, pp.356-366. ⟨10.1016/j.epsl.2015.08.018⟩. ⟨hal-01243503⟩

Share

Metrics

Record views

233