Title: Effect of particle friction and size distribution on macroscopic stress-strain relationship of sphere packings

Author (Talk): Fatih Göncü, University of Twente

Abstract:

We perform triaxial test simulations using DEM to analyze the effect of polydispersity and particle friction on the macroscopic behavior of granular packings. An increase in polydispersity leads to a decrease in confining pressure at constant volume fraction, after isotropic compression, and macroscopic friction increases and then saturates with particle friction. We systematically calibrate a simple hypoplastic constitutive model with the numerical test results to determine the dependence of material parameters of the model on the polydispersity and friction of the particles. A clear trend is observed in a certain material coefficient with increasing friction. The effect of polydispersity on material coefficients depends on initial packing conditions i.e. whether they are prepared at constant initial volume fraction or constant initial pressure.