Lateral buckling of beams in eccentrically-braced frames

Eccentrically-braced frames are used in earthquake-resistant steel structures. The key to the success of the eccentrically-braced frame is the short eccentric element used to dissipate energy during extreme seismic events. The propensity of these elements to buckle laterally under large amplitude alternating loads, and the consequences of such buckling, are studied here. The paper focuses on the effects of repeated loading on the limit load and post-limit behavior of laterally braced and laterally unbraced beams. We report the results of five experiments on propped cantilever beams subjected to cyclically reversing loads, and provide a thorough analysis of the experimental configuration.