Title Calibrating DEM simulations of cohesive solids with the Uniaxial Powder Tester Degree of recognition International Media name/outlet www.edemsimulation.com Media type Web Country/Territory United Kingdom Date 19/10/17 Description Over the years, as the popularity of the Discrete Element Method (DEM) has continued to grow, it has been increasingly used as a design tool. The accuracy of these models largely depends on the chosen DEM model and its parameters, and as pointed out in a post by David Curry (What numbers should I put in? The perennial question for DEM users) the adage of “garbage in – garbage out” holds true when carrying out DEM simulations. For cohesionless materials we have a range of parameters to account for – size, shape, stiffness and friction being some of the more commonly considered. But how many materials are truly cohesionless? Not many, so we end up having to add some additional parameters to our DEM simulations to account for the additional cohesive forces in the material. The origin of these cohesive forces and their respective mechanics vary from long and short range non-contact interaction forces, mechanical interlock, electrostatic forces, solid bridges and liquid bridges to name but a few.
So how does one go about capturing all of these phenomena in their DEM simulation? The first step is selecting a suitable contact model – a liquid bridge model is not much use for capturing the behavior of fine particles in an electrostatic field. Provided you have negotiated that stage and selected a suitable contact model; you are then faced with the much more difficult proposition of model calibration.
Persons John Morrissey