Multiscale Modelling of the Effective Viscoplastic Behavior of Mg 2 SiO 4 Wadsleyite: Bridging Atomic and Polycrystal Scale - Archive ouverte HAL Access content directly
Journal Articles Comptes Rendus Mécanique Year : 2020

Multiscale Modelling of the Effective Viscoplastic Behavior of Mg 2 SiO 4 Wadsleyite: Bridging Atomic and Polycrystal Scale

Abstract

The viscoplastic behavior of polycrystalline Mg 2 SiO 4 wadsleyite aggregates, a major high pressure phase of the mantle transition zone of the Earth (depth range: 410 − 520 km), is obtained by properly bridging several scale transition models. At the very fine nanometric scale corresponding to the disloca-tion core structure, the behavior of thermally activated plastic slip is modeled for strain-rates relevant for laboratory experimental conditions, at high pressure and for a wide range of temperatures, based on the Peierls-Nabarro-Galerkin model. Corresponding single slip reference resolved shear stresses and associated constitutive equations are deduced from Orowan's equation in order to describe the average viscoplastic behavior at the grain scale, for the easiest slip systems. These data have been implemented in two grain-polycrystal scale transition models, a mean-field one (the recent Fully-Optimized Second-Order Viscoplastic Self-Consistent scheme of [44]) allowing rapid evaluation of the effective viscosity of polycrystalline aggregates , and a full-field (FFT based [45] [33]) method allowing investigating stress and strain-rate localization in typical microstructures and heterogeneous activation of slip systems within grains. Calculations have been performed at pressure and temperatures relevant for in-situ conditions. Results are in very good agreement with available mechanical tests conducted at strain-rates typical for laboratory experiments.
Fichier principal
Vignette du fichier
CRM-Wads-revised-amsart (1).pdf (2.8 Mo) Télécharger le fichier

Dates and versions

hal-03012651 , version 1 (23-11-2020)

Identifiers

Cite

Olivier Castelnau, Katell Derrien, S. Ritterbex, P. Carrez, P. Cordier, et al.. Multiscale Modelling of the Effective Viscoplastic Behavior of Mg 2 SiO 4 Wadsleyite: Bridging Atomic and Polycrystal Scale. Comptes Rendus Mécanique, 2020, Comptes Rendus. Mécanique, 348 (10-11), pp.827-846. ⟨10.5802/crmeca.61⟩. ⟨hal-03012651⟩
212 View
77 Download

Altmetric

Share

Gmail Mastodon Facebook X LinkedIn More