Isostaticity and mechanical response of two-dimensional granular piles

Static structure and the mechanical response of two-dimensional granular piles was analyzed. The granular piles consisting of the polydisperse disks with and without friction were used for the analysis. It was observed that the static pile structure of the frictionless disks became isostatic in the rigid limit, while the isostaticity of the frictional pile depended on the pile forming procedure. It was also observed that the displacement response in each sample performed in a complicated way in the frictionless isostatic pile. The results show that total amount of the displacement in the pile caused by perturbation diverges in the case of frictionless pile as it becomes isostatic.