Softening induced instability of a stretched cohesive granular layer

Hector Alarcon (1) , Osvanny Ramos (2) , Loïc Vanel (3) , Franck Vittoz (2) , Francisco Melo (1) , Jean-Christophe Géminard (2)

1 NLPL - Laboratorio de Fisica No Lineal
2 Phys-ENS - Laboratoire de Physique de l'ENS Lyon
3 LPMCN - Laboratoire de Physique de la Matière Condensée et Nanostructures

We report on a cellular pattern which spontaneously forms at the surface of a thin layer of a cohesive granular material submitted to in-plane stretching. We present a simple model in which the mechanism responsible of the instability is the ``strain softening'' exhibited by humid granular materials above a typical strain. Our analysis indicates that such type of instability should be observed in any system presenting a negative stress sensitivity to strain perturbations.

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

Hector Alarcon, Osvanny Ramos, Loïc Vanel, Franck Vittoz, Francisco Melo, et al.. Softening induced instability of a stretched cohesive granular layer. 2010. ⟨hal-00528977v1⟩