DEM modelling of silo load asymmetry due to eccentric filling and discharge

The discrete element method is a promising approach to simulation of certain mechanical phenomena that cannot be modelled by means of the continuum mechanics approach. One of these phenomena is the anisotropy of loads exerted by granular deposits on the elements of a storage structure. In this project, DEM simulations were performed to examine the asymmetry of silo wall loads during eccentric filling and discharge of a model silo. The silo, with a diameter of approximately 26 particle diameters and a height of 2.5 silo diameters, was filled with 30,000 spherical particles. The configuration of the simulations reflected the conditions (but not the scale) of earlier laboratory tests on the filling and discharge of a 2.44-m diameter model flat-floor silo used for storage of wheat. The simulations were observed to adequately reproduce the qualitative behaviour of the loads during filling and discharge in the laboratory tests. The simulations underestimated the vertical wall loads compared with the experimental results. This underestimate is likely a result of the perfect spherical shape of the particles and the relatively weak damping of the translational and rotary vibrations in the test model.

DEM simulations were performed to examine silo wall loads during eccentric filling and discharge. The ratio of the number of wheat kernels in the silo to the number of particles in the simulation was approximately 16,000. The results of the simulations were found to adequately reproduce the quantitative behaviour of loads in a model silo storing wheat.Figure optionsDownload as PowerPoint slideHighlights
► Simulations of non-axial silo filling and discharge were performed.
► Loads simulated in 0.1 m cylinder and measured in 2.44 m diameter bin were compared.
► Simulations fairly well reproduced some effects of flow pattern and loads asymmetry.
► DEM may explain phenomena of granular mechanics un-tackled by continuum mechanics.