Discrete numerical analysis of failure modes in granular materials
Résumé
The question of failure for geomaterials, and more generally for nonassociative
materials, is revisited through the second-order work criterion defining,
for such media, a whole domain of bifurcation included in the plastic limit surface.
In a first theoretical part of the chapter, relations between the vanishing of
the second-order work, the existence of limit states and the occurrence of failures
characterized by a transition from a quasi-static pre-failure regime to a dynamic
post-failure regime, are presented and illustrated from discrete element computations.
Then boundaries of the bifurcation domain and cones of unstable loading
directions are given in fully three-dimensional loading conditions for a phenomenological
incrementally non-linear relation, and in axisymmetric loading conditions
for a numerical discrete element model. Finally, conditions for the triggering and
the development of failure inside the bifurcation domain are described and emphasized
from direct simulations with the discrete element method for proportional stress
loading paths.
Domaines
Mécanique [physics.med-ph]
Origine : Fichiers produits par l'(les) auteur(s)
Loading...