Title: The Dynamics of Failure in a 2D Granular System

Author (Poster): Jennifer Rieser, University of Pennsylvania

Abstract:

The local structural and dynamical events that precede global mechanical failure in disordered materials are not well understood. Typical experiments on real disordered systems such as metallic glasses only characterize how bulk measures of the material change as the material is strained. We hope to understand how local structure and dynamics contribute to large scale deformation by exploring the uniaxial compression of a two-dimensional granular pillar. The two-dimensionality of the system allows for direct observation of all particle dynamics throughout the deformation. The grains can be cohesive, with an attraction governed by tunable capillary forces induced through an interstitial fluid. We characterize local structure by looking at open areas, or voids, that are surrounded by closed loops of interacting particles. We observe that the packing develops more large voids in the presence of cohesion, the accumulation of which is thought to be an important contributor to large scale deformation.