Seismic Response Analysis Of LNG Storage Tank’s Vibration Isolation System

In 2013,our country has suffered from fog and haze frequently in 2013. The government has taken some air quality measures, accelerating the process of coal to gas and oil to gas. So the demand of natural gas increases across the country and the import of natural gas has been increasing. The natural gas storage facilities have been promoted Since LNG tank has very highly economic value and is an important military and civilian facility, once it fails in the earthquake, it will cause serious economic losses and casualties. So the study on isolation will not only reduce the seismic damage of LNG tank but also save the construction cost and has practical engineering significance.1.Briefly introduce the basic structure of laminated rubber and mechanical properties, summarize modal analysis methods of LNG tanks and basic theory of isolation dynamic analysis, providing theoretical basis for the passage.2.The passage is set in practical engineering, building a three-dimensional finite element model of LNG tanks with the application of ADNIA. Focus on analyzing LNG storage tank modal, Prestressing steel distribution and tension will not affect the outer tank modal of LNG storage tank, The inner tank has a smaller impact on the outer tank frequency. The outer tank has a larger impact on the inner tank liquid-solid coupling frequency. Isolation devices can reduce the model of LNG storage tank3.This paper selects the same parameters of two types of rubber,1S =30, 2S are respectively 5and 5.5. Comparative analysis and concluded, Isolation system can effectively reduce the seismic response of LNG storage tanks, but2 S has a smaller impact on damping rate. Changing the parameters of the LRB, controlling isolation frequency ω=2 ~ 5rad/ s, controlling damping ratio ξ =0.2 ~ 0.5, That can effectively change LNG storage tanks damping rate.After using the isolator, we can not only effectively reduce the seismic response LNG storage tanks, but also save costs, reducing cost accounting for 1.8% of the total cost.