Modelling realistic shape and particle inertia in DEM

The use of clumps of overlapping spheres in DEM can be used to represent realistic particle shapes. This Technical Note discusses a method that is simple and fast, and highlights the key parameters influencing particle resolution. However, the problem with overlapping mass is that the density is non-uniform, which leads to incorrect moments of inertia and therefore rotational resistance. This Technical Note addresses this issue, and proposes a simple method to reduce the error in the principal moments of inertia. The effect on a falling heap of ballast particles is shown; the method improves not only behaviour, but also computational time.