Title :

Multiscale modeling of the effective viscoplastic behavior of Mg 2 SiO 4 wadsleyite: bridging atomic and polycrystal scales

Author(s) :

Castelnau, O. [Auteur]
Laboratoire Procédés et Ingénierie en Mécanique et Matériaux [PIMM]
Derrien, K. [Auteur]
Laboratoire Procédés et Ingénierie en Mécanique et Matériaux [PIMM]
Ritterbex, S. [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Ehime University [Matsuyama, Japon]
Carrez, Philippe [Auteur]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Cordier, Patrick [Auteur]
Institut universitaire de France [IUF]
Unité Matériaux et Transformations - UMR 8207 [UMET]
Moulinec, H. [Auteur]
Laboratoire de Mécanique et d'Acoustique [Marseille] [LMA ]

Journal title :

Comptes Rendus. Mécanique

Volume number :

348

Pages :

827-846

Publisher :

Cellule MathDoc/CEDRAM

Publication date :

2020-12

Article status :

Publié

ISSN :

1873-7234

English keyword(s) :

Earth mantle
Multiscale modelling
Dislocations
Polycrystal
Viscoplasticity

HAL domain(s) :

Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]
Planète et Univers [physics]/Sciences de la Terre

English abstract : [en]

The viscoplastic behavior of polycrystalline Mg2SiO4 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 ...
Show more >The viscoplastic behavior of polycrystalline Mg2SiO4 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 dislocation 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 [1]) allowing rapid evaluation of the effective viscosity of polycrystalline aggregates, and a full-field (FFT based [2, 3]) 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.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

European Project :

Rheology of Earth materials: closing the gap between TIMEscales in the laboratory and in the MANtle
Rheology of Earth materials: closing the gap between TIMEscales in the laboratory and in the MANtle

Administrative institution(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Research team(s) :

Plasticité
Plasticité

Submission date :

2021-01-19T09:19:49Z
2021-01-19T11:31:29Z
2021-01-19T13:26:57Z