DEM and FEM simulations in magnetorheology: aggregation kinetics and yield stress

Abstract

Modeling MR fluids is a challenging task that has been undertaken from different points of view and using different computational methods. In particular, the use of microscopic approaches is of outstanding interest today. Among the different microscopic approaches reported in the literature, DEM simulations have proved to be strong candidates to model MR fluids because they are able to gather the most basic features under static and flow conditions. DEM simulations are shown here to appropriately capture the aggregation kinetics of dilute MR fluids as well. On the other hand, FEM simulations are a complementary tool to accurately ascertain magnetostatic interparticle forces. Although this type of simulation is hard to implement in dynamic systems with a large number of particles due to its high computational cost, it is demonstrated here that it is still very useful in the precise determination of the yield stress in concentrated MR fluids.