Simulation of powder behavior based on discrete model taking account of adhesion force between particles (first report) -two-dimensional simulations

An attempt is made to a new compaction model, which may agree well with experimental result when the particles are very adhesive. Adhesion force by liquid bridge between particles is incorporated in the present simulation. The simulation of two particles' collision is first performed, and then movements of free falling 1000 particles are calculated. When two particles collide with one another, they stick together. When 1000 particles fall by the gravity, they form clusters. Then, simulations of compaction of 1000 particles are carried out by the present model and the conventional model in which adhesion force of liquid bridge is not considered. In the early stage of these simulations, particles stick together continuously in present model while particles move apart from each other after a brief moment of collision in conventional model. It causes higher compressive stress and less homogeneous distribution in the present model. Furthermore, simulations of unloading in these two models are compared. In the present model, compact body keeps the shape after unloading while particles part each other in the conventional model. Thus, the effect of adhesion of particles is found very clearly in these simulations.