Microstructural evolution in diffuse granular failure: force chains and contact cycles

A Tordesillas (1) , Luc Sibille (2) , S. Pucilowski (1) , François Nicot (3) , F. Darve (4)

1 Department of Mathematics and Statistics [Melbourne]
2 GeM - Institut de Recherche en Génie Civil et Mécanique
3 UR ETGR (ETNA) - Érosion torrentielle, neige et avalanches
4 3SR - Laboratoire sols, solides, structures - risques [Grenoble]

We focus on structural evolution inside a deforming granular material, in threedimensions, undergoing the so-called diffuse failure, i.e. failure in the absence of strain localization.We uncover and characterize quantitatively the basic building blocks for self-organization,enabling comparisons of the material's rheology to those recently reported for dense materials undergoing localized failure. The building blocks consist of: (i) the quasi-linear, load-bearing force chains, and (ii) their supporting network of contacts, the minimal n-cycles. Our preliminary study shows that, similar to localized failure, self-organization in the system gives rise to major load-bearing, columnar force chains which are supported laterally by truss-like 3-cycles. Under continued loading, the force chains ultimately fail by buckling, precipitating a catastrophic collapse of the material. However, unlike localized failure, the buckling events uncovered here do not appear to be localized.

Mots clés: MATERIAU; RHEOLOGIE; MATERIAUX GRANULAIRE; MATERIEL DE PROTECTION

Domaines: Sciences de l'environnement

A Tordesillas, Luc Sibille, S. Pucilowski, François Nicot, F. Darve. Microstructural evolution in diffuse granular failure: force chains and contact cycles. Second International Symposium on Computational Geomechanics (ComGeo II), Apr 2011, Dubrovnik, France. 10 p. ⟨hal-00654281⟩