Simplification of dry gas holder structure

Due to the large geometric size of the gas holder, the calculation amount is very large during the finite element analysis. Therefore, the gas holder is simplified as follows:
(l) When establishing the finite element model, the external elevator, external stairs, various gas vent pipes, internal elevator and other ancillary facilities are not considered.
(2) The influence of piston structure on the cabinet is not considered. The main function of the piston is to seal the gas and keep the gas pressure at normal pressure. When the piston structure rises and falls along the column on the inner wall of the cabinet, its dead weight is balanced by the gas pressure at the lower part. At the same time, there is an interaction force between the piston guide wheel and the cabinet during the sliding process, but this force only exists in a small range, and its impact is far less than that of other loads such as gas pressure on the cabinet. Therefore, the influence of piston structure can not be considered in the finite element analysis of the whole cabinet.
(3) The side plate rib and plate part are modeled separately. For the construction of the orthotropic side plate shown, at present, there is no suitable element in ANSYS to consider two plates with different properties together, but the plate and the rib can be modeled separately. The plate part is simulated by the shell element which can input the orthotropic material, while the rib is simulated by the space beam element.
(4) The plate ribs of ventilation tower and cabinet roof are not considered. The ventilation tower can be regarded as an independent structure that is simply supported on the upper ring of the middle ring beam of the top of the cabinet, which has a certain increase in the rigidity of the central part of the top of the cabinet. This increase can be considered by appropriately increasing the section of the middle ring beam of the top of the cabinet during modeling.