Dynamic Response Study Of The Cylindrical Liquid Storage Tank With Annular Baffles And Base Isolation

The large vertical cylindrical storage tank is one of the important facilities for constructing the national oil and gas safety system.Its main features are large volume and thin tank wall.However,with its own stiffness and ductility to resist the effects of earthquakes,it is impossible to ensure the safety of the tank and to be vulnerable to devastating disasters such as fires and explosions.Based on the existing research progress,this paper selects the rigid liquid storage tank with annular baffles and base isolation as the research object,and studies the effect of the comprehensive protection mechanism of the baffle and the base isolation.The main research contents are as follows:(1)For the fluid region with the annular baffle,the natural frequency and mode of fluid sloshing in the cylindrical liquid storage tank with an annular rigid baffle are obtained by the fluid subdomain method,the component variable method and the vibration mode superposition method.The lead rubber bearing is selected as the base isolation device.Substituting the velocity potential function into the free liquid surface equation,and using the orthogonality of the fluid free sloshing mode and the D' Alembert principle,the dynamic response equation of an annular rigid baffle and base isolation liquid storage tank is established.According to the seismic response results of the liquid storage tank with a rigid baffle and base isolation,the influence of the period of base isolation,the size of the baffle and the position of the baffle on the shock absorption effect of the tank is discussed in detail.(2)Based on the solution method of the fluid velocity potential in a rigid baffle tank,the solution of the fluid velocity potential in the cylindrical liquid storage tank with an annular elastic baffle is obtained.The velocity potential function is substituted into the dynamic equation of the elastic baffle and the free liquid surface wave height equation.According to the equivalent mechanical principle,the equivalent mechanical model with an annular elastic baffle and base isolation liquid storage tank is established.On the basis of the seismic response results of the liquid storage tank with an elastic baffle and base isolation,the influence of the period of base isolation,the size of the baffle and the position of the baffle on the damping effect of the tank is discussed in detail.(3)Generalized coordinates are introduced to extend the free surface wave height and velocity potential,including the Stokes-Joukowski potential.Based on the fluid subdomain method,a method for solving Stokes-Joukowski potential is proposed.Based on the kinematics and dynamics boundary conditions on the free surface,a dynamic response equation for the liquid storage tank with multiple rigid annular baffles is established.The numerical results obtained by ADINA software verify the correctness of the dynamic response equation.According to the response results under pitching excitation,the influence of the baffle parameters and the pitching excitation frequency on the dynamic response of the liquid storage tank is discussed in detail.