3D FEM ANALYSIS OF PREDOMINANT RESPONSE FOR BASE ISOLATED STEEL CYLINDRICAL TANK

Liquefied Storage Tanks are a very important structure. They are widely used in daily human life, industrial chemical sector, and recently in nuclear power plants. During past earthquakes they have suffered significant damage, this damage was generally caused due to their complex seismic behavior response. Tank failure during earthquake can lead to great financial loss, environmental pollution, and life's loss. The aims of the study investigated the implantation of seismic isolation system in cylindrical steel storage tanks using bilinear hysteretic lead rubber bearing. 3D finite element method model is developed taking into account Fluid-Structure-Interaction using ANSYS software. The free vibration results of the fixed-base tank model have verified with the EC8-4 standard. To evaluate the accuracy of the seismic isolation system, a comparison of fixed and isolated tanks has been performed to evaluate their effect in the predominant response (impulsive and convective modes) of the tank structure with different water height levels to the tank capacity. The obtained results confirm the direct effect of the seismic isolation system on the response of liquid storage tanks. It was also observed that the isolation mode dominates the tank response.