Powder Technology, Vol.256, 210-216, 2014
DEM simulations of loads on obstruction attached to the wall of a model grain silo and of flow disturbance around the obstruction
In the design of a storage silo usually an axially symmetric state of stress is assumed. However, unsymmetrical pressure distribution may occur because of such factors as: non-uniform humidity of the material, eccentric filling or/and discharge, and additional construction elements inside the deposit. Small internal construction members act similarly to structural imperfection and can initiate buckling, while larger flow obstacles can markedly alter the stress distribution. A study was conducted to numerically simulate the effect of plane (2D) or block (3D) obstruction attached to the wall in a model grain silo holding wheat. This work compares the results of earlier laboratory testing and numerical simulations using the discrete element method (DEM). Series of the DEM simulations were performed with an assembly of 75000 spherical particles with random uniform distribution of diameters with a mean of 3.8 mm and range of +/- 1% placed in the cylindrical container with a diameter of 0.12 m. The set-up of DEM simulations reproduced earlier laboratory tests performed in the model grain silo, 1.83 m in diameter with flat floor and corrugated wall. Despite the very large difference in the number of particles in real and simulated deposits, the results of simulations and laboratory testing were in fairly good agreement. (C) 2014 Elsevier B.V. All rights reserved.