Calculation of the deflected mode of conical roofs under the symmetric load

This paper deals with the studying of internal forces which appear in ribs of conical roofs of vertical cylindrical capacities because of the influence of the most possible loads such as their own weight, weight of manufacturing equipment, velocity head of wind and snow pressure. Particularly, interest gives an opportunity to calculate all elements of the roof according to flat design models, using equations in a convenient analytical form. It will allow reducing complexity of the calculation and setting up a number of general regularities of internal efforts distribution. It was used two types of constructions for the analysis. They are the roof that have only the main radial ribs and the roof with one distance stiffening washer with or without secondary beams. Meanwhile, we can use several variants of the design model, which depend on the selected element such as the main radial beam, secondary beam and strengthening ring. All connections of ribs between themselves and the body are hinged. The influences of the secondary elements which provide an additional spatial rigidity (extensions, struts) on the distribution of efforts in ribs are not considered. It is allowed that the body of shield is rigid enough in the place of connection of the roof and the capacity's wall in order to radial displacements of its points is considered to be small enough. Definition of the deflected mode of the roof construction is considered in the context of checking calculation of cross-section bearing capability with clearly conditioned geometries of all elements, and also in case of search optimal ratio of geometry of all elements of the roof when the necessary bearing capability is achieved. Purpose. To define the main internal efforts for the main radial and strengthening ring of conical roofs of different constructions under the symmetric loads and to form simple analytical dependences from the point of view of the design practice. Conclusion. By using the sequential analysis it was obtained expressions to equations of internal efforts of elements of the conical roof and revealed critical design sections to analyzed variants. It was given analytical expressions and tables of coordinate values, which uniquely defines position of potentially dangerous sections, and also equations to calculate maximum values of compression force and bending moment.