Evaluation of North American Standards for Lateral- Torsional Buckling Capacity of Steel I-Beams with Extended Shear Tab Connections

Steel shear tab connections connect beams to columns and girders. While extended shear tab (EST) connections have been studied for stability and strength, their impact on the lateral torsional buckling (LTB) capacity of I-beams has not been explored. To address this research gap, the present study uses finite element (FE) modelling to examine how EST connection details affect the LTB capacity of I-beams. Several parameters, such as shear tab thickness, bolt configurations, unbraced beam length, bolt distance from the supporting member, and stabilizer plates, are examined. Results show that steel stabilizer plates can significantly improve LTB resistance of laterally unsupported I-beams with EST connections, by up to 61% compared to unstiffened connections. However, beams connected through unstiffened ESTs, regardless of whether a single or double vertical bolt arrangement is used, may exhibit substantially lower LTB strengths than those predicted by CSA S16-19 and ANSI/AISC 360-22, particularly in deeper sections. Finally, an alternative connection configuration employing a standard channel section in place of the conventional shear tab plate is also investigated. FE analysis shows that this channel-based detail can improve the LTB capacity of I-beams by about 27% for the W410X54 beam section, compared to standard shear tab connections.