Study On Sloshing Resistance For Large Liquid Storage Tank Subjected To Seismic Excitation

With the booming development of China's economy,the demand for energy such as petroleum is growing dramatically,and the vertical storage tanks are the most important energy storage facilities,and their demand is also growing.As a facility for storing flammable and explosive materials,once damage occurs,it not only causes directly serious disasters such as fires,but also causes other disasters such as environmental pollutions.Therefore,it is of great practical value to conduct seismic research on liquid storage tanks.Under strong earthquakes,liquid sloshing in the liquid storage tank will adversely affect the tank structure.In order to solve such problems,an annular baffle device can be installed in the liquid storage tank to control the liquid sloshing response.In order to investigate the influence of the baffle plate position and size in the liquid storage tank on the liquid sloshing response,this study is based on the large general finite element software ADINA.Assuming that the liquid is a viscous and incompressible fluid,the baffle is shaped as a thin circular plate and perpendicular to the tank wall,and establish a foundation-tank-liquid interaction system.Firstly,the static and modal analysis of the liquid storage tank system without baffle plate is carried out and then the results are compared with the results of relevant criterions.Moreover,the parametric analysis of the liquid sloshing response in the baffled tank under horizontal seismic excitation is carried out thoroughly.On the basis of these results,Backpropagation Neural Networks(BPNN)is employed to predict the optimal baffle size and position in the liquid storage tank.The main research contents of this thesis are as follows:(1)Static and modal analysis of the numerical model established in this study,the static fluid pressure,displacement,stresses and the natural frequency of the liquid storage tank are calculated,and compare the calculation results with the results of relevant standards as well as mathematical methods to verify the correctness and rationality of the model.(2)The EI-Centro earthquake record was selected for dynamic time history analysis in this study.50 different working conditions of baffle plate positions and sizes were investigated.The influence of the annular baffle on the liquid sloshing wave height in the liquid storage tank was analyzed carefully.The calculation results show that:The annular baffle has a significant influence on the sloshing wave height of the liquid in the liquid tank.Specifically,the smaller baffle size and be placed close to the liquid surface,the smaller liquid sloshing wave height is.(3)Based on the artificial neural network model,the optimal position and size of the annular baffle are obtained.After using BPNN the sloshing wave height of the liquid in the liquid storage tank is only 41%of the maximum sloshing wave height in the unbaffled tank,that is to say,the addition of the baffle plate can significantly reduce the sloshing response in the storage tank under seismic excitation.