Mechanics Analysis Of The Steel Concrete Composite Structure Of The 30000m~3 LNG Storage Tank Dome

Design and construction of large concrete liquefied natural gas (LNG) storage tank, have a significant influence on the transition of china’s energy structure. In this paper, a 30000 m3 sized LNG storage tank was taken as the research object, then the dome of steel and concrete composite structure integration model is established and the finite element numerical simulation method was used to analyze the relationship of stress and deformation of the dome structure under static state in the pouring stage and the mechanics mechanism of dome steel-concrete composite structure. The research contents are as follows:Based on the finite element program ANSYS, the first concrete case under the influence of dome steel shell and reinforcement bars of the geodesic dome, which can be divided into two different working conditions by whether the first pouring concrete is under consideration,were static analyzed respectively to obtain the relationship between stress and vertical displacement of dome steel-concrete composite structure. The results show that two kinds of the steel beam section stress distribution on pouring concrete parts is completely different, the steel girder section stress distribution law on not pouring concrete parts is basically different.The analysis result of the stress distribution of the steel beam section shows that the steel concrete composite structure can be regarded as a whole structure.In the second segmented casting condition, the concrete cast before this condition has reached its full design strength and the concrete cast this time does not meet all its design strength, We investigated the second concrete cases with geodesic dome for static analysis,and get the distribution regularity of stress and the vertical displacement of dome of steel and concrete composite structure. The results show that the variation of radial stress along the radial direction is consistent with the stress form of the non hinged arch along the radial direction, the radial beam is eccentric compression in the form of eccentric compression, and the stress form is shown as eccentric tension in the form of non concrete parts; so that shows the steel concrete composite structure can be regarded as a whole structure.We investigated the no steel reticulated shell of the reinforced concrete domee for static analysis,and get concrete and reinforcing steel bar distribution regularity of stress and vertical displacement. The results show that the dome reinforcement stress without lower layer steel reticulated shell is about 3 times than the reinforcement stress with the lower layer of steel reticulated shell, and the lower layer steel reticulated shell decreases the stress of the upper steel bar; The vertical deformation of the dome without the lower layer steel reticulated shell is basically the same as the vertical deformation of the dome with the lower layer steel reticulated shell, and both of the vertical displacement is about 3mm; So the lower layer steel reticulated shell can effectively reduce the stress of the steel bar, and change the distribution of the stress distribution of the section.