Experimental techniques for steel silo transition junctions

Large elevated steel silos general 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 due to the radial 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 experimental study has been reported in the open literature due to the great difficulties associated with testing these thin-shell junctions at model scale. This paper provides a description of the development of an experimental facility for testing model junctions. Issues covered include the fabrication of quality model junctions using thin steel sheets, the loading method and the precise three-dimensional measurement of geometric imperfections and deformed shapes using a laser-displacement meter. Typical experimental results of a cone-cylinder-skirt junction are also presented.