Static and dynamic analysis of the flow of bulk materials through silos

Storing and handling of bulk materials are essential aspects of grain, chemical and mining operations. Problems that commonly occur in silo operation mainly include flow blockages and structural failure of silos, which reduce the silo capacity and cause high maintenance cost. In most cases the problems occur principally due to inadequate design analysis together with a lack of knowledge of dynamic behaviour of the bulk material containment structure system during the discharge of materials from silos. This thesis focusses on the simulation of the filling and the discharge process of bulk materials in silos. Emphasis has been placed on the development of the numerical methods for the prediction of bulk material pressures on silo walls and the internal stresses in silo shells under both static and dynamic conditions. The motion of bulk materials flowing through silos is modelled as the motion of a no-tension, viscous, elastic-plastic material. A s large deformation occurs during discharge of the material, geometry nonlinearity is considered in the analysis. A finite element method formulated in terms of velocity as the primary variable is developed for the simulation of the flow of bulk materials and the structural response of the silo shell. The behaviour of the flowing bulk material is coupled with the behaviour of the containment structure by the contact condition of the bulk material and the silo wall. A computer program has been developed for the analysis.

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