Evaluating the Structural Response of Moment Resisting Frames and Eccentrically Braced Frames Under Lateral Loads

Abstract This study investigates the lateral displacement and lateral load capacity of two types of structural systems: Moment Resisting Frames (MRF) and Eccentrically Braced Frames (EBF), in relation to varying numbers of stories. The analysis was performed using a pushover method, evaluating displacement and shear capacity across structures with 3, 6, 9, and 12 story. The results indicate that as the number of story increases, the lateral displacement in both systems increase, but EBF structures exhibit significantly reduced displacement compared to MRF structures. Specifically, EBF reduces displacement by 84.46% for 3 story and by 86.12% for 12 story. Conversely, the Lateral Load capacity of EBF decreases as the number of story increases, but remains higher than that of MRF structures. EBF increase lateral load Capacity by 76.54% for 3 story and by 68.61% for 12 story. Performance evaluations, conducted according to FEMA 356 standards, reveal that MRF structures maintain a Life Safety (LS) level of performance, with some buckling in beams and failure at moment connections, while EBF structures perform at an Immediate Occupancy (IO) level, showing minimal damage. These findings underscore the advantages of EBF in terms of displacement reduction and overall performance in multi-story buildings.