Towards a complete macroscopic modelling of the thermo-chemomechanical behaviour of MIECs

Olivier Valentin (1) , Eric Blond (1) , Nicolas Richet (2)

1 PRISME - Laboratoire Pluridisciplinaire de Recherche en Ingénierie des Systèmes, Mécanique et Energétique
2 CRCD - Centre de Recherche Claude Delorme [Jouy-en-Josas]

This paper proposes a macroscopic model of the thermo-chemo-mechanical behaviour of MIECs dedicated to mechanical engineering. Developed within the framework of phenomenological approach, the state variables of the model are the oxygen partial pressure, the temperature and the total strain. Oxygen bulk diffusion is describes by the local Onsager approach and surface exchange are modelled by the use of a mass Biot number. Not only focus on the semi-permeation induced strain, the proposed model also included the effect of the temperature. Strain predicted by a model based on defect equilibrium and strain predicted by the macroscopic approach are in good agreement as it is illustrates on the particular case of La0.8Sr0.2Fe0.7Ga0.3O3-δ. The implementation of the model in the F.E.A code Abaqus allows the exploration of the evolution of the stress state during the membrane life, from sealing stage to reactor exploitation.

Mots clés: MIECs; Chemical expansion; Thermo-chemo-mechanical behaviour

Domaines: Mécanique des matériaux [physics.class-ph]; Mécanique des matériaux [physics.class-ph]

Olivier Valentin, Eric Blond, Nicolas Richet. Towards a complete macroscopic modelling of the thermo-chemomechanical behaviour of MIECs. 12th Conference of European Ceramic Society, Jun 2011, Stockholm, Sweden. pp.Oral 214. ⟨hal-00611383⟩