Dynamic behaviour of Liquid Storage Tanks with Optimization of Elements Dimensions

Liquid storage tanks are considered as a vital artery with high importance. Therefore, the dynamic behavior of liquid storage tanks should be investigated. In this study, At first, the verification of finite element method based on the result of scaled experimental tank with different dimensions of elements was done.Then, modal and time history analyses were conducted and the free surface sloshing was investigated. The results of different element types were compared with the experimental results used statistical program SPSS17. In the next step a concrete rectangular tank with 1000m3 capacity was studied with different dimension of elements. Finally, the time history of North ridge earthquake record was applied to 1000m3 tanks with two and three horizontal and vertical components and the result of this analysis was evaluated. The results of modal and time history analyses showed that the effect of dimension of elements on the response is considerable and modal analysis alone cannot validate the modeling of tanks with the finite element method and the dimensions of elements with ratio height to length larger than 1 did not show good agreement as well as the results of dynamic analyses showed that The presence of vertical earthquake ground motion in combination with horizontal ground motion do not have any significant effect on the sloshing behavior water in the tank. However, the vertical earthquake acceleration can have remarkable effects on the maximum hydrodynamic pressure, and its distribution on the tank walls.