Papers by Keyword: Wall Pressure

Abstract: Interaction between granular solids and boundary structures is a fundamental problem encountered in bulk solids handling and subsurface structural design. Current understanding of its mechanism has not been adequate for robust and economical engineering designs, especially for flexible boundary structures. A classic and essential example is uniaxial compression of dry granules in a deformable cylindrical container, where the response of the confined granules under axial loading and the load transmission to the contacting structure still remain not fully understood. This paper comparatively studies such a confined compression scenario using a newly developed numerical procedure (Linked DEM-FEM) and a conventional FEM approach. The examined system involved around 7700 polystyrene beads contained in an acrylic thin-walled tube supported at one rim and gagged by two end platens. The compression was applied by displacing one end platen at a constant rate while fixing the other. Characteristics of the compression system, including load-displacement response, force transmission to boundary structure, mobilised bulk wall friction coefficient, and stress distribution on the wall, were evaluated. The majority of the compared physical quantities show reasonable to good agreement, thus giving a convincing quantitative verification for both approaches.

Abstract: With the increasing volume demand of silos, silo diameters are bigger and bigger. However, present wall pressure computation methods are mostly based on small diameter silos. To solve this problem, systematical research on the wall pressure in large diameter silos is of great importance. For now, in the Chinese code the wall pressure computation methods are based on the limit equilibrium theory to be calculated, which define the orientation of the rupture plane in the bulk solid within the silo. The rupture angle is a key parameter to silos’ wall pressure. Therefore the value and direction of rupture angle are researched by theoretical method in this paper, which has heavy significance and provide an important basis for the large diameter silo design.

Abstract: This paper introduces a finite element solution for predicting the normal pressure on large diameter squat silo wall, with the application of contact element and nonlinear model. The finite element analysis (FEA) described in this paper is compared with the full-scale tests and Coulomb theory and the Chinese Code. The predicted results are in good agreement with Coulomb theory, when the top of the stored solid is horizontal; while the result of Coulomb theory is much larger than the other solutions, when the top of the stored solid is a conical surcharge pile. The results from the modified Rankine theory in Chinese Code are acceptable in both conditions. Finally, the effects on the normal pressure of Young′s Modulus are also discussed.