Discrete particle model for morphologic and mechanical study

Abstract

The behaviour of three-dimensional granular media was studied using spheres, examining the response of coarse particles in a 1 m edge cubic cell. The media were adjusted to a predetermined material grain size distribution and subjected to the same boundary conditions as in previous laboratory tests. The study observed how forces are distributed and how the particles are deformed when an external load is introduced to the system. The equations considered are the Hertzian elastic contact law and the Coulomb slip law. In this way, the force of the contacts is calculated with Hertz's law and the force developed is limited by that established using Coulomb's law, allowing relative slip between particles when such a force is reached. Both morphologic and mechanical analyses were carried out. The morphologic analysis studied the way particles adjust in the cell and the mechanical analysis studied the forces and settlements developed. In addition, both analyses were related to determine if there is a relation between the morphology of a coarse granular medium and its mechanical response. Using these two analyses, the paper attempts to explain and model the behaviour and the response of granular media, comparing this response with one obtained from previous laboratory tests, to deduce if the proposed model is adequate for representing laboratory tests.