Interaction between dry granular materials and an inclined plate (comparison between large-scale DEM simulation and three-dimensional wedge model)

The interaction between dry granular materials and an inclined plate is numerically studied using a three-dimensional discrete element method (DEM) simulation. In the simulation, a plate is dragged horizontally through densely packed dry granular materials. To examine the effect of the rake angle α of the plate on the drag force acting on the plate, three cases with α = 50°, 70°, and 90° are compared (α = 90° for a vertical plate). The results show that for all cases, the force oscillates as the plate advances. As α decreases, the amplitude and frequency of the force oscillation decrease and increase, respectively. The force oscillation is attributed to the periodic evolution of a shear band formed in the materials. The relationships between the rake angle, evolution of the shear band, and drag force can be explained quantitatively by using a three-dimensional wedge model considering the variation of the local volume fraction inside the shear band.