Law of the Variation of Maximum Static Friction Force with Height in Granular Materials

The law of the variation of the maximum static friction force exerted on a rod immersed in a granular matter with the filling height of the granules was experimentally studied. Moreover, a continuum media model was used to calculate the maximum static friction force exerted on the rod. It was observed that the maximum static friction force was proportional to the depth square of the filling granules at a granular filling height below the double cylinder diameter and linearly proportional to the filling height at a granular filling height above the double cylinder diameter. At the same time, the theoretically calculated maximum static force exerted on the rod immersed in a granular matter agreed well with the experimental one.