Simulation of macroscopic deformation using a sub-particle DEM approach

A limitation in numerical modelling of the ironmaking blast furnace is the inability to quantify the effects of particle deformation and subsequent loss of porosity arising from the softening and melting of ferrous materials. Previous attempts to consider deformation focused solely on the macroscopic effects such as resistance to gas flow, with an assumed decrease in porosity proportional to temperature. Instead, it is proposed to approximate particle scale deformation using a modified sub-particle Discrete Element Method approach, where each “ore” particle is represented using an agglomerate of discrete elements with temperature dependent properties. Cohesive forces binding the agglomerate were obtained from standard models (Linear Hysteretic, a simplified Hertz-JKR, and Linear Bonding models). This paper considers the limiting case of a two-particle agglomerate, in order to assess how physically realistic the behaviour is under external force conditions including uni-axial tension and rotation. This approach has also been extended to a single full sized agglomerate to demonstrate deformation behaviour in compression and tensile tests. Future work will apply this approach to multiple agglomerates to simulate the shape change of materials as they undergo softening and melting.