Development of a microscopic damage model for low stress triaxiality

Mohamed Achouri (1) , Guénael Germain (1) , Philippe Dal Santo (1) , Jean-Lou Lebrun (1)

1 LAMPA - PMD - Laboratoire des Arts et Métiers ParisTech d'Angers - Procédés Matériaux Durabilité

This work deals a contribution to ductile damage of High-Strength Low-Alloy (HSLA) steel steels under low stress triaxiality. This work is based on micrographics observations and in situ shear tests to examine the evolution of microstructure in this kind of loading and to identify the damage process associated. Numerical simulations by finites elements has been performed to simulate the material behavior of nucleation mechanism and the interaction between cavities during the coalescence phase, as well as the effect of the relative position of the inclusions in the shear plane. The model used as a reference in this work is the Gurson-Tvergaard- Needleman (GTN) model. It has been recently improved in order to take into account the effects of low triaxiality during shearing. The implementation of this model in a finite element code is in progress.

Mots clés: HSLA steels; ductile damage; shear; micrographic analysis; in-situ tests; numerical simulation

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

Mohamed Achouri, Guénael Germain, Philippe Dal Santo, Jean-Lou Lebrun. Development of a microscopic damage model for low stress triaxiality. Key Engineering Materials, 2011, 473, pp.460-467. ⟨10.4028/www.scientific.net/KEM.473.460⟩. ⟨hal-00793187⟩