Influence of dry cohesion on the micro- and macro-mechanical properties of dense polydisperse powders & grains

Multi-Scale Mechanics, Faculty of Engineering Technology (ET), MESA+, University of Twente, Enschede, The Netherlands

^* e-mail: r.g.h.kievitsbosch@student.utwente.nl

Published online: 30 June 2017

Abstract

Understanding how cohesive granular materials behave is of interest for many industrial applications, such as pharmaceutical or food and civil engineering. Models of the behaviour of granular materials on the microscopic scale can be used to obtain macroscopic continuum relations by a micro-macro transition approach. The Discrete Element Method (DEM) is used to inspect the influence of cohesion on the micro and macro behaviour of granular assemblies by using an elasto-plastic cohesive contact model. Interestingly, we observe that frictional samples prepared with different cohesion values show a significant difference in pressure and coordination number in the jammed regime; the differences become more pronounced when packings are closer to the jamming density, i.e. the lowest density where the system is mechanically stable. Furthermore, we observe that cohesion has an influence on the jamming density for frictional samples, but there is no influence on the jamming density for frictionless samples.