Combined bending and torsion of steel I-shaped beams

Abstract

Tests were conducted on six simply supported wide flange beams of Class 1 and 2 sections. The primary experimental variables included class of section, bending moment to torque ratio, and the inclusion or omission of a central brace. The end restraint and loading conditions were designed to simulate simply supported conditions at both end supports and a concentrated force and moment at midspan. Initial bending moment to torque ratio varied from 5:1 to 20:1. A finite element model was developed using the finite element software ABAQUS. Although the initial linear response was predicted accurately by the finite element analysis, the ultimate capacity was underestimates. A comparison of the test results with the design approach proposed by Driver and Kennedy (1989) indicated that this approach is potentially non-conservative and should not be used for ultimate limit state design. A design approach proposed by Pi and Trahair (1993) was found to be a suitable approach for ultimate limit states design.