Techniques for buckling experiments on steel silo transition junctions

Abstract Large elevated steel silos generally consist of a cylindrical vessel, a conical discharge hopper and a skirt which may either be supported on the ground or by a number of columns. 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 previous experimental study has been reported. This has been due to the great difficulties associated with testing these thin-shell junctions at model scale. This paper first describes the development of an experimental facility for testing model steel silo transition 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–ring junction are next presented to demonstrate the capability of the developed facility. Procedures for processing the test results to determine both the buckling load and the number of buckling waves are also presented.

[1]  C. R. Calladine,et al.  Paradoxical buckling behaviour of a thin cylindrical shell under axial compression , 2000 .

[2]  J. Michael Rotter,et al.  Collapse Behavior and Strength of Steel Silo Transition Junctions. Part I: Collapse Mechanics , 1991 .

[3]  A. Y. Elghazouli,et al.  Measurement techniques for buckling sensitive composite shells , 1998 .

[4]  Johann Arbocz,et al.  Buckling experiments : experimental methods in buckling of thin-walled structures , 2000 .

[5]  P. J. Dowling,et al.  Fabrication of small scale stiffened cylindrical shells , 1987 .

[6]  Chiara Bisagni,et al.  Experimental Buckling of Thin Composite Cylinders in Compression , 1999 .

[7]  J. M. Rotter,et al.  Buckling of Simple Ringbeams for Bins and Tanks , 1983 .

[8]  Jin-Guang Teng.  Intersections in steel shell structures , 2000 .

[9]  Yuan-Cheng Fung,et al.  Thin-Shell Structures: Theory, Experiment, and Design. , 1974 .

[10]  Haim Abramovich,et al.  The development of shell imperfection measurement techniques , 1995 .

[11]  J. M. Rotter,et al.  Imperfection measurement of cylinders using automated scanning with a laser displacement meter , 1996 .

[12]  J. F. Jullien,et al.  Buckling of shell structures, on land, in the sea, and in the air , 1991 .

[13]  Francesco Benedettini,et al.  Buckling Experiments: Experimental Methods in Buckling of Thin–Walled Structures Vol. 1: Basic Concepts, Columns, Beams and Plates J. Singer, J. Arbocz and T. Weller John Wiley & Sons, Chichester , 1999 .

[14]  J. E. Harding,et al.  Buckling of shells in offshore structures , 1982 .

[15]  J. G. Teng.  Plastic buckling approximation for transition ringbeams in steel silos , 1997 .

[16]  J. M. Rotter,et al.  Recent research on the behaviour and design of steel silo hoppers and transition junctions , 1992 .

[17]  Thomas Ummenhofer,et al.  On the modelling of different types of imperfections in silo shells , 1995 .