Dynamic Response And Seismic Reduction By Anti-sloshing Analysis On Large-scale LNG Storage Tanks

LNG storage tanks have been widely used as main equipments of LNG receivingterminal in the world. As LNG storage tanks gradually develop toward large-scale andhigh intensity seismic region, their design and construction process is becoming moreand more complex. At present, China has not yet mastered the core technology ofLNG storage tanks. Some researches are limited to the static analysis and constructiontechnologies, but less about the dynamic response, anti-sloshing, and vibrationreduction, etc. Therefore, considering the country’s economic and social development,strengthening the foundation researches, especially the study about the earthquakesuch as seismic resistance, reduction and isolation, is beneficial to improve China’senergy structure, as well as protect the ecological environment and establish domesticautonomic design system of LNG storage tanks. Based on the practical engineeringproject and the use of ADINA, the LNG storage tank’s dynamic characteristics,seismic response and seismic reduction by anti-sloshing were detailed analyzed andresearched. The main parts are described as follows:1．According to engineering design data of the existing LNG storage tank, thisdissertation made a parallel design of the inner tank. Then, on the base of designparameters, two kinds of three dimensional finite element models (stiffening rings andwithout stiffening rings) were created using ADINA. At the same time, the liquidmodel was established and liquid-solid coupling effect considered.2．The dynamic characteristics, including the inner-tank’s basic vibration modelof liquid-solid coupling and sloshing as well as the out-tank’s basic vibration model,were studied and compared with the theoretical formula values.3．Selecting typical class II venues waves, including two natural waves and anartificial wave, the seismic response of LNG storage tanks was studied usingacceleration vibration input method. Based on this, some important indexes wereobtained and analyzed, such as acceleration and displacement envelope curve alongheight direction, the stress distribution, and the base shear, overturning moment, thesloshing wave height and hydrodynamic pressure.4．The seismic response of LNG storage tanks with stiffening rings, includingdifferent parameters such as quantity, size and position, was disserted and compared with the former analysis results. According to the indexes of base shear, overturningmoment, the sloshing wave height and so on, the effect of stiffening rings was studied.Based on this, the dissertation provided a reasonable design scheme of arranginganti-sloshing type reinforcing rings.By comparative analysis of the computed result and theoretical formula values,the dissertation revealed the failure mechanism and provided an important referencefor seismic design of LNG storage tanks.