Buckling experiments on transition rings in elevated steel silos

Abstract

Large elevated steel silos for the storage of bulk solids generally consist of a cylindrical vessel, a conical discharge hopper, and a skirt. The cone-cylinder-skirt junction is subject to a large circumferential compressive force, which is derived from the horizontal component of the meridional tension in the hopper, so either a ring is provided or the shell walls are locally thickened to strengthen the junction. Many theoretical studies have examined the buckling and collapse strengths of these junctions, but no previous experimental study has been reported due to the great difficulties associated with testing these thin-shell junctions at model scale. This chapter presents the results of a series of tests on cone-cylinder-skirt-ring junctions in steel silos under simulated bulk solid loading. In addition to the presentation of test results including geometric imperfections and failure behavior, the determination of buckling modes and loads based on displacement measurements is examined in the chapter. It presents the results of five tests on cone-cylinder-skirt-ring junctions under simulated bulk solid loading. For each model junction, the initial imperfect surface is carefully surveyed before loading. The deformed shape of a circumference on the ring is monitored during the loading process. These measurements of initial shapes and deformed shapes are interpreted by Fourier decomposition, and it leads to the conclusion that most of the short-wave buckles are amplified from initial geometric imperfections.