Numerical Simulation Of Static And Dynamic Bulk Material Pressure Of Steel Silo

The silos are widely used for the storage of various bulk materials. It is important to determine the granular material pressure for silo designing. Because of some assumptions for the theoretical analysis of granular material pressure, there exist differences between the calculation results and the real ones. Besides, the experiments are rather complex and difficult, it is necessary to carry out the numerical analysis.The three dimensional finite element models for the simulation of granular material pressure for steel silos are established. The stored granular material is considered to follow a law of behavior of isotropic elastic material with the Drucker-Prager plasticity criterion in the plastic range, and the interaction between the stored material and the silo wall is simulated by the rigid-flexible contact model and the face-to-face contact method. Granular material pressures for various types of steel silos are simulated employing the proposed FE model. The static behaviors including vertical displacement, contact pressure and plasticity strain of granular materials are presented in the paper, and the results are compared with the Eurocode and the Chinese design code for grain steel silos. Furthermore, the influences of weld depression and temperature are considered, which find that the weld depression leads to the retribution of granular material pressure and the temperature influents the plastic strain mostly.This paper successfully realizes the three dimensional finite element simulation of steel silo considering the elastic-plastic of bulk materials and the interaction between the bulk material and silo under the horizontal earthquake load. The dynamic displacement, velocity, acceleration and the dynamic pressure are time-history analyzed. The shear and moment of the silo bottom are compared to the calculation results of the Chinese design code using the basic shear method. It is found that the calculation of Chinese code is rather rough and conservative and the ela-plastic time-history analysis is recommended to examine the response of silo in the earthquake fully.When the nonlinear buckling of silo is studied, the silos are usually under the axial compression as well as some inner pressure, both of which would influence the buckling strength. Therefore, the paper carries out the buckling strength study of silos with the weld depression considering the granular material pressure. The research finds that the more number of circumferential welds, the greater decreased of the buckling strength; the form and location of the weld depression would influent the buckling strength of silos.