Morphological effects on the angle of repose of granular materials: a discrete element investigation

Abstract

We investigate the effects of morphological features on the angle of repose (Φ) of granular materials using a three-dimensional discrete element method (3D-DEM). A commercially available DEM package called particle flow code (PFC3D) was used. The elliptical clumped particles were imported in the form of an STL file, which was modelled by controlling two morphological descriptors (i.e., β and ξ) using a multi-sphere (MS) approach. The β represents the maximum pebble-pebble intersection angle and ξ defines the ratio of smallest to largest pebble diameter within a clump. The results concluded show that the Φ increase with an increase in static friction coefficient became insignificant after µs = 0.8, whereas the Φ decrease with a decrease in the number of pebbles. In addition, the microscopic parameter in terms of coordination number (Z) shows an initial concave response and stabilized with a further subsequent increase in the number of pebbles. These results are of particular interest which could provide insights into the microscopic level of interactions at particulate levels of granular materials.