The NAFEMS Eastern European 2020 Virtual Conference took place on the 23rd and 24th of September 2020. The event gave participants access to high level presentations in the field of structural mechanics, computational fluid dynamics, electromagnetics and discrete element methods.

Resource Abstract

The discrete element method (DEM) is a wide family of numerical methods for discrete and discontinuous modelling of materials and systems which can be represented by a large collection of particles (discrete elements) interacting with one another by contact or by long range forces. Being a relatively new numerical method, the DEM has become a powerful tool for predicting the behaviour of various particulate and non-particulate materials such as soils, powders, rocks, concrete, ceramics and even metals.



The motion of the discrete element is described by the Newton-Euler rigid body dynamics equations which are integrated in time using explicit or implicit schemes. The disadvantage of the explicit integration scheme is its conditional numerical stability imposing the limitation on the time step. Despite this drawback the explicit integration is most often used because of simple and easy implementation, high computational efficiency of the solution for a single step and lack of problems with convergence required in implicit schemes.

Discrete elements can be of an arbitrary shape, however, spherical particles are often a preferable choice because of the simplicity of the formulation and the computational efficiency of contact detection algorithms for spherical objects.

The lecture will be illustrated with numerical results of various engineering problems including granular flows, rock mechanics, powder metallurgy, fluid-particle flows and others.