Lateral torsional buckling of rafters in tank structures and the stabilizing influence of the roof

Abstract

The chapter discusses lateral-torsional buckling of rafters in tank structures and the stabilizing influence of the roof. The chapter focuses on the structural failure due to lateral-torsional buckling of the radial rafters caused by external loading or internal vacuum pressure. The lateral-torsional buckling strength of the rafters is studied with respect to the supporting effect of the tangential trusses and the stabilizing influence of the roof plates. The influence of the supporting effects is investigated for six real roof structures with diameters ranging from 20 to 45 meters and compared with German codes. Recommendations for the interpretation of numerical investigations in considering conceivable factors such as boundary conditions or the loosely attached thin steel roofing are given in the chapter. The chapter presents the results of a recent study on the carrying behavior of rafters of tank roofs prone to lateral-torsional buckling.