Seismic Response Analysis Of LNG Storage Tank With Three-Dimensional Isolation Bearing

In recent years,with the increasing use of clean energy liquefied natural gas(LNG,Liquefied Natural Gas),the safety and seismic resistance of LNG tanks has been paid more and more attention.At present,the isolation of storage tank is mostly horizontal isolation,but the research shows that the vertical seismic action has a great influence on the seismic resistance of storage tank,this paper uses large general finite element analysis software ADINA to simulate and analyze the seismic response of three-dimensional isolation bearing LNG tank,and studies the horizontal and vertical isolation effect of three-dimensional isolation bearing on the tank.The results of the study are as follows:(1)By using the finite element software ADINA to simulate the LNG storage tank,the shaking frequency and coupling frequency of the tank are solved,and compared with the relevant theoretical specifications and tests,the error is within the acceptable range,which verifies the feasibility of using ADINA software modeling.(2)Aiming at 1000m3 storage tank,a new three-dimensional isolation bearing system is designed,which includes horizontal isolation layer and vertical isolation layer,combined with three-dimensional isolation bearing design theory,the stiffness and damping of horizontal isolation layer and vertical isolation layer are studied,and the mechanical parameters of three-dimensional isolation bearing which are matched with the seismic performance of 1000m3 tank are obtained.(3)The model of 1000m3 tank is established by using ADINA finite element software,calculating and analyzing the seismic response of non-isolated storage tank,laminated rubber bearing isolation storage tank and three-dimensional bearing isolation storage tank.The results show that,compared with the non-isolated storage tank,the three-dimensional isolation bearing can effectively reduce the acceleration,dynamic water pressure and effective stress of the tank,and the reduction amplitude is 61.20%,91.08%,16.27%,compared with that of the non-isolated storage tank,the laminated rubber isolation bearing can effectively reduce the acceleration,dynamic water pressure and effective stress of the tank,and the reduction amplitude is 63.03%,91.39%,17.93%.The horizontal damping effect of three-dimensional isolation bearing is close to that of laminated rubber isolation bearing,which can reduce the seismic response of storage tank.Under vertical seismic excitation,compared with non-isolated storage tank,the acceleration,dynamic water pressure and effective stress of the three-dimensional isolation bearing are reduced by 86.19%,62.43%,20.06% respectively,and compared with the non-isolated storage tank,the acceleration,dynamic water pressure and effective stress of the laminated rubber isolation bearing on the storage tank The 4.93%,0.58%,5.76% were reduced separately.The results show that the three-dimensional isolation bearing designed in this paper has good horizontal and vertical isolation effect.(4)By changing the parameters of isolation period,isolation damping ratio,seismic intensity,site condition and liquid level height,the seismic response of three-dimensional isolation bearing LNG storage tank under different parameters is compared and analyzed.The results show that the three-dimensional isolation bearing has better damping effect on the seismic response of storage tank under high intensity when the seismic intensity changes.The site type has an effect on the seismic response of three-dimensional support isolation storage tank,and the seismic isolation effect is the best for the hard earthquake wave in the field.When the height of the liquid surface changes,the three-dimensional bearing isolation effect is the best when the height of the liquid surface is high.In the design of tank,according to the characteristics of the tank itself,the reasonable isolation period and reasonable isolation damping ratio can be selected to effectively reduce the seismic response of the tank.