Force distribution in a granular medium under dynamic loading

Abstract

Force distribution in a granular medium subjected to an impulse loading is investigated in experiment and computer simulations. An experimental technique is developed to measure forces acting on individual grains at the bottom of the granular sample consisting of steel balls. Discrete element method simulation also is performed under conditions mimicking those in experiment. Both theory and experiment display exponentially decaying maximum force distributions at the bottom of the sample in the range of large forces. In addition, the simulations also reveal exponential force distribution throughout the sample and uncover correlation properties of the interparticle forces during dynamic loading of the granular samples. Simulated time dependence of coordination number, orientational order parameter, correlation radius, and force distribution clearly demonstrates the nonequilibrium character of the deformation process in a granular medium under impulse loading.

Influence of wall friction on granular column

“…[25] The bimodal character of force distribution is observed in experiments employing dynamic loading and slow shear. [26,27] Several formulas of the normal force distributions have been developed from empirical data or theoretical models (see Table 1). Moreover, many influential factors of this distribu-tion have been proposed.…”

Statistical Properties of Shear Deformation of Granular Media and Analogies with Natural Seismic Processes

“…It is worth noting that similar properties are also endowed with granular media under shear deformation [13]. Experimental studies and computer simulation of deformation of granular massifs indicate that fluctuations of intergranular forces and velocities of granules can many times exceed their mean values [33][34][35][36] that is common to seismic processes [15] as well. During the deformation of granular systems, the long-range correlations [37] are intensified.…”