The Effect Of Interaction Laws On The Stresses In Frictionless Granular Media

Introduction One out of many interesting features of granulates 1 is the stress distribution in static arrays of sand. The pressure in a silo filled with grains does not increase linearly with depth as in the case of a liquid filling. Instead, the stress saturates at a certain value 2 due to arching and internal friction. Thus the walls of the silo carry a part of the materials' weight. In a pile of sand where no vertical walls are present the total weight of the pile is carried by the bottom. However, the distribution of forces under and inside the material is not yet completely understood. Experiments on piles with many thousands of particles reveal a relative minimum in the vertical stress at the bottom of the pile, the so-called dip. 3;4 In the presence of disorder, stress chains are observed, i.e. stresses are mainly transported along selected paths, and the probability distribution of stress spans sev