Study On The Buckling Behavior Of Thin-walled Cylindrical Shells With Large Rectangular Opening

The smoking desulfuration absorber tower for large electric power plant is a kind of thin-walled container with large diameter, opening space. Because of the large opening in the shell,the cross section is reduced and the continuity of the structure is damaged. Large increment ofmembrane stress at the edge of the hole results in the reduction of the shell buckling load andthe ultimate load-carrying capacity. So study on buckling behavior of cylindrical shells withlarge opening is of theoretical and practical value.The structure form and load condition of cylindrical shells with large opening is complexand the influence factors on the stability are various. So it is very difficult to work out the modeand buckling load by the classic analytical methods. Using finite element methods, the bucklingbehavior of cylindrical shells with large rectangular opening is analyzed in this paper for thepurpose of practical application.Firstly, eigenvalue buckling is carried out to predict the buckling mode and critical load. Itis found out that the upper limit buckling load of cylindrical shell with rectangular opening ismuch less than the lower limit value of the perfect cylindrical shell. This shows that thebuckling load is obviously decreased because of the large rectangular opening.Secondly, the load-displacement response of the structure is computed with geometricallynonlinear analysis and the orthogonal design method is adopted to discuss the influence ofgeometric parameters on the buckling load. The considered parameters include the openingwidth, the opening height, and the location in the longitudinal direction, radius-to-thickness ratioand height-to diameter ratio of the shell. It is found out that the buckling load of cylindrical shellwith rectangular opening is mainly dependent on the radius-to-thickness ratio of the shell.It is also been shown that reinforcement can often improve the load-carrying capacity. Theeffects of stiffening on shell structures with large rectangular opening are studied in this paper atlast. Three types of stiffening rings are proposed. The effects of various types of stiffening ringson the buckling behavior are discussed on condition that the stiffened areas are equal to eachtype. It is found out that T formed stiffening ring is better to improve the load-carrying capacity.Four types of stiffening plates are proposed. The effects of various types of cutoutreinforcement on the buckling behavior are discussed through geometrically nonlinear analysis.It seems clear that completely stiffening can make the stress distribution relatively uniform and solve the stress concentration of upper boundary, which leads to overall buckling of thestructure.Lastly, optimal suggestions are proposed on smoking desulfuration absorber tower forLinhe Electric Power Plant according to the study result, which can reduce the steel quantityand construction cost effectively.Because there is no special design code of smoking desulfuration absorber tower in ourcountry, the conclusions proposed in this paper are of guiding significance for optimization ofabsorber tower, flue gas import and export and stiffening.