Quantitative simulation of mechanical properties of porous ceramic materials by discrete element method

Abstract

In this work, the mechanical response of porous ceramic was investigated by performing discrete element method (DEM) simulations. Isotropic packing strategy was adopted to prepare numerical samples with different densities. For each numerical sample, the contact size between particles was calculated using Coble’s sintering model. To account for the spatial coupling effect between solid bonds under multi-contact condition, the classic Hertz contact model was modified by introducing a correct factor which reflects the influences of contact size in-between grains and the geometrical arrangement of grains. The quantitative predicting ability of the built DEM framework was then evaluated by using the partially sintered alumina ceramic as investigated system. It was demonstrated that the predicted effective Young’s modulus and fracture strength are both in quantitative agreement with experimental data. As to partially sintered alumina ceramic containing large pores, both the interaction behavior between pores and the influence of the geometrical arrangements of pores on effective Young’s modulus and fracture strength predicted by the theoretical analyses or finite element method were successfully captured by our DEM simulations. All these quantitative comparisons demonstrate that the built DEM framework can be used to quantitatively model the mechanical properties of porous ceramics.