Lateral-Torsional Buckling of Nonprismatic I-Beams

A finite-element formulation for the lateral-torsional buckling analysis of nonprismatic I-beams is developed. The formulation is capable of analyzing continuous I-beams with a linear or quadratic taper within acceptable accuracy. The influence of warping deformations of the section and location of the member loads at different cross-section points are included in the formulation. Finite-element solution convergence is studied based on available experimental and numerical results. A parametric study on the lateral-torsional buckling strength is carried out for different forms and degrees of taper, loading, and support conditions for single-span and two-span continuous beams. The buckling strength of beams with various degrees of taper and number of spans are also investigated.