Towards Completeness, a Multiscale Approach of Confined Particulate Systems

Numerical simulation and computational visualization of the failure characteristics of confined granular assemblies, e.g., sand, gravelo ro ther 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 ac omplete twoscale homogenization procedure, including both acontinuous and adiscontinuous scale. Thus, we combine the capability of discrete methods to describe the behavior of the single grains and the possibility of acontinuum approach to discretize the overall structure. Connections between the twoscales are based on the concept of introducing arepresentative volume element on the discrete microscale. Drivenbyquantities from the macroscale, the representative volume element acts likeam aterial law, returning the needed quantities to the continuous macro level. The particular challenge of this work lies in defining the connection between these twoscales in terms of physical quantities and equations on the one hand and in terms of introducing appropriate visual tools which ultimately yield an improvedunderstanding of these complexcou-pling mechanism on the other hand. Simulation of the distinguishing and complicated behavior of granular media calls for the mobilization of multiscale simulation techniques. While standard continuum methods strand by reproducing distinguishing behaviors, e.g., the breaking and forming of contacts between the grains, discrete methods are limited due to their computational costs. Am ultiscale combination of both methods leads to ap owerful and efficient simulation tool. Thereby,afinite element method (fem)d iscretizes the overall structure on the ma-103