| dc.description.abstract | The purpose of this study is to investigate the mechanical response of a granular assembly under confined compression by using discrete element modelling. The effects of inter-particle friction coefficient, particle-wall friction coefficient, inter-particle restitution coefficient, and packing structure on the internal physical properties of the unbroken particles were extensively examined. The packing structures studied here include FCC, BCC, HCP and random configurations. In addition, the effect of bond strength on the mechanical behaviour and the pulverization mechanism of the crushable particles was also examined. Several key findings are highlighted as follows: (1) As the particle-wall friction increases, the average coordination number of the region near the upper circumference gradually reduces. Similarly, the average coordination number of the upper region decreases with the increase of the inter-particle friction. This also makes the hardening area extend from top to bottom; (2) For the four packing structures studied here, the contact number generally decreases with the increase of height. Only random packed structure exhibits uniform distribution of the contact orientation in the horizontal plane, whereas BCC, FCC and HCP packed structures show anisotropic distributions. The contact forces in all the four packing structures show a strongly anisotropic distribution in the vertical plane; (3) As the bond strength increases in one direction or both directions, the self-supporting capacity of granular assemblies is enhanced, leading to strong loading stiffness. In addition, the contact force intensity increases with bond strength. The enhancement of bond strength does not tend to dissipate the system energy, so the contact forces can transmit into the deeper depth. However, the orientation distribution of contact forces in the vertical plane does not change significantly with the increase of bond strength, and exhibits strongly anisotropic characteristics, especially for a large portion with low contact angles. | en_US |