ABSTRACT
A method for determining the critical buckling moment of a web-tapered I-beam with stiffening ribs is presented, employing potential energy calculations based on the Rayleigh–Ritz method. The approach identifies the critical moments at which lateral buckling initiates in simply supported, web-tapered steel I-beams with ribs. Specifically, the study focuses on lateral-torsional buckling in beams with tapered webs and varying numbers of stiffener ribs. Comprehensive numerical and parametric analyses are conducted, considering uniformly distributed design loads applied in three scenarios: to the top flange, the shear center, and the bottom flange. The parametric analysis of a ribbed tapered beam reveals that the combined tapering of both the web and the stiffener ribs has a greater impact on the critical moments than tapering the web alone.
