ABSTRACT
A procedure for calculating the critical buckling moment of a web-tapered I-beam with stiffener ribs is proposed, using potential energy calculations using the Rayleigh–Ritz method. The solution identifies the critical moments where lateral buckling begins in simply supported, web-tapered steel I-beams with ribs. In particular, lateral-torsional buckling is considered in beams with tapered web, and with various numbers of stiffener ribs. Detailed, numerical, parametric analyses are carried out. Uniformly distributed design loads are considered across three cases: applied to the top flange, to the shear center, and to the bottom flange. A parametric analysis, of a tapered beam with ribs, demonstrates that tapering of both the web and stiffener ribs influences the critical moments more than tapering only the web.
