ABSTRACT
In this article we investigate the influence of different parameters on the angle of repose. In both experiments and simulations via the discrete element method (DEM), the angle of repose, a fundamental quantity for the experimental classification of granular materials, depends crucially on the particles properties. Previous simulations for the angle of repose of dry granular materials used compositions of round particles and neglected friction (Gallas & Sokolowski 1993; Pöschel & Buchholtz 1993) and relied on the interlocking of grain surfaces (see Fig. 1) or neglected the rotational degree of freedom (Lee & Herrmann 1993). As a result, the slopes of the heaps were not smooth and straight, but rough and curved, which is typical for wet/cohesive, not for dry granular materials (Barabasi, et al. 1999; Schinner & Mattutis 1999). These simulations resorted to using rough grounds to retain a certain verisimilitude, though heaps of dry sand can be built even on “microscopically” flat mirrors.
