Strain localization analysis deduced from a large strain elastic-plastic self-consistent model for multiphase steels

Gérald Franz (1) , Farid Abed-Meraim (1) , Tarak Ben Zineb (2) , Xavier Lemoine (3) , Marcel Berveiller (1)

1 LPMM - Laboratoire de physique et mécanique des matériaux
2 LEMTA - Laboratoire d'Energétique et Mécanique Théorique et Appliquée
3 ArcelorMittal Maizières Research SA

In order to investigate the impact of microstructures and deformation mechanisms on the ductility of materials, the criterion based on bifurcation theory first proposed by Rice is applied to elastic-plastic tangent moduli derived from a large strain micromechanical model combined with a self-consistent scale transition scheme. This approach takes into account several microstructural aspects for polycrystalline aggregates: initial and induced textures, dislocation densities, softening mechanisms so that the behavior during complex loading paths can be accurately described. Based on this formulation, Forming Limit Diagrams (FLDs) are derived and compared with a reference model for multiphase steels involving linear and complex loading paths. Furthermore, the effect of various physical and microstructural parameters on the ductility limit of a single-phase steel is qualitatively studied with the aim of helping in the design of new materials.

Mots clés: Bifurcation theory; Complex loading; Deformation mechanism; Dislocation densities; Elastic-Plastic; Forming limit diagrams; Large strains; Micromechanical model; Microstructural aspects; Microstructural parameters; Multiphase steel; Polycrystalline aggregates; Reference models; Scale transition; Self-consistent model; Softening mechanisms; Strain localization analysis; Tangent moduli

Domaines: Génie des procédés; Matériaux; Mécanique [physics.med-ph]; Génie mécanique [physics.class-ph]; Matériaux et structures en mécanique [physics.class-ph]; Mécanique des matériaux [physics.class-ph]; Mécanique des solides [physics.class-ph]; Mécanique des structures [physics.class-ph]; Micro et nanotechnologies/Microélectronique

Gérald Franz, Farid Abed-Meraim, Tarak Ben Zineb, Xavier Lemoine, Marcel Berveiller. Strain localization analysis deduced from a large strain elastic-plastic self-consistent model for multiphase steels. 12th International Conference on Fracture, Jul 2009, Ottawa, Canada. pp.5004-5014. ⟨hal-01234657⟩