Safety Analysis For The Large-scale Silo

With the development of economics and the richness of various resources, more and more things need to be stored or processed and so the applications of silo come into popular, then there a need for elevating the safety levels of such structures. Cylindrical steel silos are the most frequent now, compared with traditional reinforced concrete ones, they have advantages of simple structure, short application period and quick profit. Cylindrical steel silos are composite structures that constructed of spiral thin steel shell, rings reinforced, vertical stiffness reinforced and trusses that strengthen the top. The mechanical behavior and failure criterion are quite complex and they are also sensitive to boundary conditions. There are usual accidents to silos that constructed under existing technical specifications and the most frequent failure mode are buckling under vertical loads. We can do some rational structure design to elevate their safety levels.This article use certain silo as its background, use big powerful FEM software ABAQUS to establish its 3D model and give its static mechanical behavior a detail analysis and checking, and we get a satisfying results. Then we use FEM numerical method, including liner eigenvalue buckling and geometry nonlinear buckling, to process an analysis of it under vertical loads, and get the critical buckling load of the silo.For the silo shell, we take the upper part of it , exploring liner eigenvalue analysis method, investigate the efforts of the silo shell thickness, the ring reinforced separation distance, the vertical reinforced number and cross-section area on the critical buckling load. The results reveal that: the critical buckling load has a second power relationship with the silo shell thickness and a liner relationship with the reinforced cross-section area. Both exploring polynomial and least squares fits to the numerical results we get the same relationship. So the large the number of the reinforced, the high the critical buckling load gets. For the ring reinforced circumstance, when the separation distance has a relation with axial half-wavelength, the critical buckling load gets relatively higher. For the vertical reinforced circumstance, when the reinforced number is little, the buckling of the silo shell became significant, when the number if large, the buckling of the reinforced become significant. This article gives some suggestions which have some guidance value for real engineering projects.