Study On The Seismic Response Of Liquid-storage Tanks By Ale Method

The large liquid-storage tanks are widely used in petroleum, chemical, metallurgy, warehousing and other industries. In the earthquake, the damage of tanks occurred from time to time, which led to serious secondary disasters sometimes. Therefore, it is necessary to study the seismic dynamic response of the tanks, with providing theoretical and technical support for its anti-seismic design, earthquake damage assessment.For simpleness requirement, in the anti-seismic design of tanks, the interaction between the liquid and tank wall is simplified, and the effect of the foundation is not comprehensive considered, so the resulting calculation error may lead to greater damage risk. In the present thesis, the arbitrary Lagrangian Eulerian Method is used in the dynamic analysis of Liquid-storage Tanks under the earthquake, in order to simulate the liquid sloshing effects and the fluid structure coupling. The region which the liquid may reach is meshed by ALE gridding, and the ALE coupling is used in the fluid-structure interaction. In addition, to considering the interaction between the tank and the foundation, the foundation is established with soil-spring constraints, and the seismic load is applied to the foundation directly.Base on that above, the seismic response of the liquid-tank-foundation composite system is analyzed by the commercial software MSC.DYTRAN ? under the Tangshan, EI-Centro and Wenchuan wave. The major work of this paper is as follow.First, by calculating the dynamic response of the Liquid-storage tank under the horizontal earthquake, It is observed that, the liquid in the tank waves in its natural frequency, and the smaller the excitation frequency, the greater sway amplitude; Under the earthquake excitation, the tank leans, and the maximum axial and radial stress values at the bottom of the tank wall are much higher than the normal steady-state values, which may cause the "foot as" buckling.Second, by analyzing the seismic response of the Liquid-storage tank with changing the height of the liquid, it shows that, with the liquid height increased, the shaking intensity of the free surface becomes smaller, and the tank stress increases, while the shear force at the bottom decreases.Third, by calculating the dynamic response of the Liquid-storage tank under the horizontal and vertical Wenchuan earthquake, the results show that, under the excitation of Wenchuan wave, the liquid sloshes larger, and more severely near the tank wall; the maximum Mises effective stress value of the tank is close to yield value, and the maximum shear force value at the bottom is larger.