Karen Daniels, Department of Physics, NC State – Applied Mathematics Colloquium

Title: The role of force networks in static and flowing granular materials

Abstract: Granular materials are inherently heterogeneous, and continuum models of properties such as the shear modulus and sound speed often fail to quantitatively capture their dynamics. This lack of understanding has serious consequences for the engineering of both geotechnical applications, and the industrial storage and handling of granular materials. One likely reason for these difficulties is that boundary stresses are transmitted via a chain-like network of strong forces. In my talk, I will describe several experiments on two-dimensional photoelastic granular materials which bridge particle-scale, meso-scale, and continuum-scale approaches. These experiments allow us to both investigate the statistical ensembles from which force networks are drawn, as well as probe their effects on mechanical properties such as sound transmission and rheology.