(122a) Discrete Element Simulations of Floor Pressure Due to Granular Material in a Cylindrical Vessel

Near the end of the 19th century, H. A. Janssen discovered that the floor pressure in a container of granular material asymptotes exponentially to a value less than the weight of the material, i.e., the pressure becomes independent of the fill height of the column. This phenomenon is investigated using discrete element simulations of inelastic, frictional spheres in a cylindrical vessel having a particle-to-cylinder diameter ratio of approximately 13.3. We compute the load experienced by a piston that is slowly displaced downward at a rate of 0.001 diameters per second for several values of the wall friction coefficient. Our simulated behavior of the load vs. fill level was found to fit well with the functional form of Janssen's theory. Quantitative differences with experimental measurements and possible reasons are discussed.