Buckling strength of T-section transition ringbeams in elevated steel silos and tanks

A ring is generally provided at the intersection between the cylinder and the cone of an elevated storage silo or tank to resist a large circumferential compressive force at the intersection (the transition junction). This ring is a main structural member and is often referred to as a ringbeam (in contrast to relatively light rings as stiffeners on shell walls). The ringbeam may be an annular plate, but an annular plate is weak in torsion and is thus susceptible to failure by out-of-plane buckling. A common way to increase the out-of-plane stiffness of an annular plate ringbeam is to attach a vertical stiffener to the outer edge of the annular plate, resulting in a T-section ringbeam. This paper describes a simple approximate method developed in recent studies for assessing the out-of-plane buckling strength of these ringbeams. The method may be used in practical design directly and is suitable for future inclusion in relevant design codes.