Regensburg 2002 – wissenschaftliches Programm
DY 46.56: Poster
Donnerstag, 14. März 2002, 15:30–18:00, D
Wetting and Mechanics in Granular Systems — •Dimitrios Geromichalos, Michael Schulz, Beatrix Schulz, Frieder Mugele, Mika Kohonen, and Stephan Herminghaus — Abt. Angewandte Physik, Universität Ulm, 89069 Ulm
The complex interplay of fluid invasion, decompaction, and mechanical properties in granular materials is of substantial interest in engineering as well as in geosciences and other disciplines. In order to understand these enormously complex systems, imbibition in disordered media must be well understood as well as the impact of the presence of inner liquid surfaces upon the mechanical response of the system to external shear. We have thus started by studying imbibition in a well defined disordered medium in two dimensions. We have, for the first time, found the theoretically predicted crossover from local to KPZ behaviour, and thereby the self-generation of a characteristic length scale. First experiments in three dimensions, which have been performed within a pile of polydisperse glass beads, show similar results. We have furthermore performed simulations of a slightly polydisperse pile of spheres with interactions as come about from liquid bridges. A critical shear force, at which the pile yields, is clearly observed. First experiments are shown which are designed as to match the simulation as close as possible.