title: Softening induced instability of a stretched cohesive granular layer.
abstract: 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 a type of instability should be observed in any system presenting a negative stress sensitivity to strain perturbations.
authors.affiliation: Departamento de Física, Universidad de Santiago de Chile, Avenida Ecuador 3493, Casilla 307, Correo 2, Santiago, Chile.
authors.forename: Hector
authors.initials: H
authors.lastname: Alarcón
authors.forename: Osvanny
authors.initials: O
authors.lastname: Ramos
authors.forename: Loïc
authors.initials: L
authors.lastname: Vanel
authors.forename: Franck
authors.initials: F
authors.lastname: Vittoz
authors.forename: Francisco
authors.initials: F
authors.lastname: Melo
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Géminard