The Dynamic Response Analysis Of Liquid-storage Tank Subjected To Seismic Excitation

Liquid-filled tank is widely used by many industries in China, especially by petroleum and chemical industries, and the capacity of liquid-filled tank becomes bigger and bigger. Since most stored things are combustible and explosive, once they are damaged, the consequences are inconceivable. The destruction of the tank is due to earthquakes primarily, so its seismic research has been the hot point all the time.Rigid and flexible tanks are researched primarily. The seismic responses of the tank are discussed when it is in the general circumstance, supported by periodic ground motion and ground pulse movement. The hydraulic pressure, natural frequencies and seismic response formulas of the tank are introduced. The seismic responses of a large liquid storage tank are calculated. In order to satisfy the requirements of engineering practice, some simplified formulas of the hydraulic pressure of the rigid and flexible liquid storage tanks are introduced. Housner and Veletsos simplified methods are used respectively. The Haroun-Housner simplified mechanical model is introduced in the part of the earthquake-resistant design. The Wilson method and time-history analysis method are adopted; and according to the model, the EL-Centrol and Tianjin seismic waves are inputted, a computer program is given, and the dynamic characteristics and seismic responses of every mass of the model are obtained. The natural vibration characteristics are analyzed by using the finite element analysis software ANSYS.Some things are found through study: the first order vibration mode is generally increased when the liquid of the tank is considered, but the second and third order vibration modes are reduced. It is very important to consider the elastic deformation of the tank in the seismic research. The accuracy of using Housner and Veletsos simplified method in the seismic research is proved; the importance of considering the influence that the sloshing mass of the liquid on the stability of the tank in the seismic research is proved.