Towards completeness, a multiscale approach of confined particulate systems

Abstract

Numerical simulation and computational visualization of the failure characteristics of confined granular assemblies, e.g., sand, gravel or other types of loose aggregates, is the focal point of this publication. In general, standard continuum descriptions are exhausted if applied to loose granular materials, while discrete formulations fail to describe huge overall particulate structures. We propose a complete two scale homogenization procedure, including both a continuous and a discontinuous scale. Thus, we combine the capability of discrete methods to describe the behavior of the single grains and the possibility of a continuum approach to discretize the overall structure. Connections between the two scales are based on the concept of introducing a representative volume element on the discrete microscale. Driven by quantities from the macroscale, the representative volume element acts like a material law, returning the needed quantities to the continuous macro level. The particular challenge of this work lies in defining the connection between these two scales in terms of physical quantities and equations on the one hand and in terms of introducing appropriate visual tools which ultimately yield an improved understanding of these complex coupling mechanism on the other hand.