title: Self-stresses and crack formation by particle swelling in cohesive granular media.
abstract: We present a molecular-dynamics study of force patterns, tensile strength, and crack formation in a cohesive granular model where the particles are subjected to swelling or shrinkage gradients. Nonuniform particle size change generates self-equilibrated forces that lead to crack initiation as soon as the strongest tensile contacts begin to fail. We find that the tensile strength is well below the theoretical strength as a result of inhomogeneous force transmission in granular media. The cracks propagate either inward from the edge upon shrinkage or outward from the center upon swelling. We show that the coarse-grained stresses are correctly predicted by an elastic model that incorporates particle size change as metric evolution.
authors.affiliation: LMGC, CNRS-Université Montpellier II, Place Eugène Bataillon, 34095 Montpellier Cedex, France.
authors.forename: M S
authors.initials: MS
authors.lastname: El Youssoufi
authors.forename: J-Y
authors.initials: JY
authors.lastname: Delenne
authors.forename: F
authors.initials: F
authors.lastname: Radjai