Study On Seismic Performance Of LNG Storage Tank Structure With Inter-story Isolation Systems

LNG storage tank structure plays a key role in storing liquid and protecting internal equipment during the process of seismic resistance.In this paper,the inter-story isolation technology is applied to form the passive control system by modifying the traditional connection between structures,and the new structure of LNG storage tank with inter-story isolation is realized.By using inter-story isolation technology to reduce the energy input to the superstructure,the seismic response of LNG storage tank is significantly reduced.The new structure proposed in this paper is of great practical value and research significance for improving the seismic performance of storage tank structure.The focus of this paper is to study the effectiveness of inter-story isolation technology in seismic performance of LNG storage tanks.Specific research contents are as follows:1.The innovation of this paper is to realize the application of inter-story isolation technology in LNG storage tank structure.The application of this technology makes the displacement of LNG storage tank structure under earthquake mainly occur in the isolation layer structure.By modifying the traditional fixed connection between dome and tank wall to seismic isolation bearing connection,the new type of LNG storage tank with inter-story isolation is proposed.First of all,simplified analysis models of traditional structure of LNG storage tank under different working conditions such as empty tank,half tank and full tank are established based on centralized mass method and Haroun-Housner model theory.Then,a simplified two-particle analysis model of LNG storage tank with inter-story isolation structure is established.Based on this model and study of Anna Reggio,an optimization design method for mechanical parameters of seismic isolation bearing is proposed2.Modal analysis and time history analysis of various structural models of LNG storage tank are carried out by ANSYS,and the vibration characteristics and shock absorption effect of inter-story isolation structure are studied.In the process of modeling,additional mass method is used to simplify the hydrodynamic pressure of storage liquid on tank wall.Based on the establishment of finite element model of this new structure,on the one hand,the vibration characteristics of this new structure are studied by modal analysis;on the other hand,the acceleration,displacement and base shear force response of the structure can be obtained by time history analysis,and the shock absorption effect of the new structure is analyzed.In the final part of this paper,influence parameters of this new structure are analyzed by taking the mechanical parameters of seismic isolation bearings of storage tanks and different liquid level heights as influence parameters,and research results show that the new structure has good seismic robustness.