On discrete element modelling of compaction of powders with size ratio

A numerical procedure, based on a discrete element method (DEM), for analysing cold compaction of spherical powders, is presented. In the numerical model, packing followed by compaction of up to 10,000 powder particles is simulated. Perfectly plastic material behaviour is assumed for convenience, but not for necessity, and as a result, local contacts between frictionless particles are described by a linear force–displacement relation. The numerical model is described in detail and its applicability to compaction problems of different complexity is discussed. Explicit results are presented for the case of isostatic compaction of spherical powders with size ratio and include applied pressure as function of densification as well as the evolution of contacts for individual particles. The present results are compared in detail with corresponding results from previous theoretical, experimental and numerical studies and the validity of fundamental assumptions made in previous theoretical analyses are discussed.