Behavior to complete failure of steel beams subjected to cyclic loading

This paper presents an experimental study on steel beams subjected to cyclic loading to extremely large deformations. The study aims to collect information on beam hysteretic behavior up to complete failure, in the belief that such information is needed for the establishment of performance-based design. Test beams were about 1/10-scaled models, and effects of the RBS detail and lateral braces arranged at beam top flanges were examined. Behavior up to the cyclic loading amplitude of 0.06 rad was commensurate with behavior observed in many previous studies. Behavior in extremely large deformations from 0.1 to 0.5 rad amplitudes was significantly different from the behavior in large deformations (to the 0.06 rad amplitude). The RBS beam failed earlier in the reduced cross-section primarily due to strain concentrations at the section. Lateral braces also caused strain concentrations, leading to earlier fractures. Significant increase in the maximum resistance was observed in extremely large deformations for beams not braced laterally. Tensile axial forces induced in the beam according to the geometry change were responsible for the increase.