The most common way to prevent lateral torsional buckling is by employing lateral bracing. It is well known that the lateral bracing should have sufficient strength and stiffness to minimize the lateral torsional buckling. However, the lateral bracing requirements in the current code is based on elastic model and monotonic loading on simply supported beam, and for seismic design where large inelastic deformation is expected, these requirements are also used. This action becomes questionable whether it is appropriate or not. In addition, the lateral bracing requirements may be different between simply supported beam and both ends fixed beam which is commonly found in moment resisting frame with welded-flange bolted-web connections. Therefore, an analytical study was conducted on H-beams under seismic type loading to investigate the lateral bracing requirements. Two beams were experimentally tested, and finite element model was validated to experimental result. Based on the verified finite element model, parametric study was conducted. Finally, an equation to design the required bracing strength was proposed.

The most common way to prevent lateral torsional buckling is by employing lateral bracing. It is well known that the lateral bracing should have sufficient strength and stiffness to minimize the lateral torsional buckling. However, the lateral bracing requirements in the current code is based on elastic model and monotonic loading on simply supported beam, and for seismic design where large inelastic deformation is expected, these requirements are also used. This action becomes questionable whether it is appropriate or not. In addition, the lateral bracing requirements may be different between simply supported beam and both ends fixed beam which is commonly found in moment resisting frame with welded-flange bolted-web connections. Therefore, an analytical study was conducted on H-beams under seismic type loading to investigate the lateral bracing requirements. Two beams were experimentally tested, and finite element model was validated to experimental result. Based on the verified finite element model, parametric study was conducted. Finally, an equation to design the required bracing strength was proposed.

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