Plastic buckling approximation for transition ringbeams in steel silos

An annular plate ringbeam at the transition junction of a uniformly-supported steel silo or tank is subject to a large circumferential compressive force that is derived from the radial component of the meridional tension in the conical hopper. Under this compressive force, the ringbeam may fail in one of several possible modes, including out-of-plane buckling. This paper presents an investigation into the effects of various factors on the plastic out-of-plane buckling behavior and strength of this ringbeam, leading to the eventual development of a simple plastic buckling approximation for design use. The application of the proposed method is demonstrated through an example.