Drag of Two Cylindrical Intruders in a Two-Dimensional Granular Environment

The drag of two cylindrical intruders in a two-dimensional granular environment is numerically studied by the discrete element method. We find yield force, below which cannot move because interactions with surrounding particles. Above on other hand, can at constant speed. investigate relationship between force and steady speed intruders, where becomes higher as distance decreases. confirm that origin Coulombic friction particles bottom plate changing value coefficient. also almost proportional to coefficient, means number determining constant. On elasticity applicable determine stress fields around intruders. asymmetric respect direction are reproduced using information stresses surfaces introducing bipolar coordinates.