Effect of Earthquake Frequency Content on Dynamic Response of Concrete Rectangular Tanks Using Coupled Finite Element Method and Smoothed Particle Hydrodynamics

Abstract

Concrete ground tanks are widely used in storing water, sewage, oil, toxic chemicals and other liquids. Depending on their type of use, they are usually in the category of very important structures of lifelines; Therefore, the dynamic analysis of liquid storage tanks is one of the most important issues in earthquake engineering. On the other hand, the seismic behavior of the storage tanks and its interaction with liquid is very important. In this study, the water medium is modeled using smoothed particle hydrodynamics method and tank’s structure modeled by finite element method. The smooth particle hydrodynamics, which is a meshfree method, has many advantages over other traditional grid-based methods. For verification purposes, the modeling accuracy was compared with the available experimental and numerical results, the reasons and parameters that were effective on selecting the records were expressed, and then the time history analysis was performed on the modeled storage tank including records with different frequency content. The parameters of sloshing height, acceleration at the top of the tank’s wall, base shear, force per unit width and wall displacement were obtained for comparison. Finally, the effect of frequency content was studied considering the effect of water-structure interaction on the tank. The results showed that a record with low frequency content results higher sloshing height, while a record with moderate frequency content will cause larger responses on the tank’s structure despite of its lower sloshing height. The study also proved that the dominant frequencies of sloshing increases with decreasing frequency content of earthquake.

Keywords

• concrete tanks
• smoothed particle hydrodynamics
• frequency content
• sloshing height
• water-structure interaction