RESTRUCTURING OF FORCE NETWORKS

摘要

We present a model for the evolution of the force network of a granular medium under uniaxial compression. This model is based on the stiffening and the increase of resistance of parallel force lines under the action of individual restructuring events at the contacts between grains and is essentially an inversion of well-known fiber models for brittle tensile rupture. The model can be solved analytically in the experimentally most relevant case in which increase of stiffness and resistance are proportional to each other. The results for the constitutive behavior and the spectrum of the strength of acoustic signals are in good quantitative agreement with experimental measurements.