A discrete deformable element approach for the compaction of powder systems

The paper describes the application of a discrete deformable element modelling approach to simulate the compaction of a mixture of ductile and brittle powders together with an exploration of its suitability to establish the yield characteristics of powders. Two-dimensional rod models comprising ductile and brittle particles are assembled and subject to uniaxial compression in a rigid die. The utility of the method to represent the yielding of the powder is also explored by the application of a biaxial loading sequence. The model was found to be capable of modelling the behaviour of powder mixtures successfully. It captured ductile-brittle failure mechanisms in the case of brittle particles and demonstrated the effectiveness of a proportion of ductile particles in preventing the fragmentation of brittle particles in a mixture, illustrating agreement with experimental observation. The exploration of yield surface prediction was subject to a number of assumptions driven by the two-dimensional nature of the simulation, coupled with the high initial density level enforced by the particle packing. Despite these constraints, the results were encouraging when compared with experimental measurement of yield characteristics. Further work is required to establish more realistic initial density and to develop the capability to include a larger number of particles within the simulation.