ON THE MODELING OF DIFFERENT TYPES OF IMPERFECTIONS IN SILO SHELLS

The assessment of imperfections is most important for determining the load-bearing capacity of a thin-walled shell structure. Different ways of modelling imperfections are discussed in this paper and steel silo shells are used as an application. Buckling tests were performed on d ifferent types of model shell - standard qualify and high quality with reduced heat input during welding. For the numerical studies two diff erent approaches were used as well: an axisymmetric approach with subs titute geometric imperfections and an FEM approach, where the nodal co ordinates were derived from surveying the specimen. It was found that there is considerable gain in the buckling strength due to the presenc e of the granular solid. The larger rite initial imperfections in the shell the greater the gain in strength compared to the empty cylinder. The modelling of the uneveness of the edges with uneven dead loading is also discussed.