Investigation of particle shape and ambient fluid on sandpiles using a coupled micro-geomechanical model

Particle motion in granular systems is common in nature and industrial processes. Along with particle size and density, the shape of particles also plays a crucial role in the dynamic behavior of such systems. To capture the irregular morphology of particles, we have proposed an image-based discrete element method in which the effect of fluid is also considered. We have considered four cases to study how the particle shape and ambient fluid simultaneously affect the properties of sandpiles, that is dry and water-immersed sandpiles, for both irregular and spherical particles. We found that the repose angle of sandpiles is increased in the irregular models while decreased by having ambient water in the system. The contact force chains in irregular particles are also stronger than that of the spherical sandpiles. Meanwhile, the contact force chains are weakened by the ambient water. Furthermore, the largest particle displacement occurs in the spherical sandpile immersed in water.