Cohesive, frictional powders: contact models for tension

The contacts between cohesive, frictional particles with sizes in the range 0.1-10 mu m are the subject of this study. Discrete element model (DEM) simulations rely on realistic contact force models-however, too much details make both implementation and interpretation prohibitively difficult. A rather simple, objective contact model is presented, involving the physical properties of elastic-plastic repulsion, dissipation, adhesion, friction as well as rolling- and torsion-resistance. This contact model allows to model bulk properties like friction, cohesion and yield-surfaces. Very loose packings and even fractal agglomerates have been reported in earlier work. The same model also allows for pressure-sintering and tensile strength tests as presented in this study.