ABSTRACT
The analysed columns are used as supports for railroad, or tramway overhead line, or columns of portal halls hinged to the foundation. Their load-bearing capacity, which significantly depends on the spatial stability (torsional buckling, flexural-torsional buckling, lateral-torsional buckling), is influenced by the corresponding torsional stiffnesses. In this paper, there was analysed build-up columns with tapper chords laced in a single plane, which were subjected to non-uniform torsion by a concentrated moment applied at mid-length, in order to determine their torsional stiffnesses. Moreover, the critical load capacity of torsional buckling was numerically determined on the columns in question. Extensive analytical calculations were carried out, which were verified numerically with finite element method. Among other things, the geometry and the taper angle of the column chords and the geometry of the trusses were varied. The paper was ended with conclusions of a practical nature.
