Probabilistic seismic assessment of Buckling Restrained Braces and Yielding Brace Systems

The current paper investigates the effectiveness of using an innovative structural fuse named YBS over the Buckling Restrained Brace (BRB) within the context of performance-based earthquake engineering. To this end, two groups of structures equipped with BRB and YBS braces are modeled by OpenSEES platform. In the first part of the paper, simplified procedures including pushover and Incremental Dynamic Analysis (IDA) are utilized for seismic performance evaluation. In the second part, two EDP-based and IM-based probabilistic frameworks are employed to gain a more comprehensive assessment. On this basis, fragility analysis is carried out for different performance levels. Also, limit state frequencies are calculated to compare collapse capacity of both systems. Finally, confidence levels are estimated to study reliability of the structures against collapse. Results show that both systems can achieve the expected performance objectives. However, YBS represent superior performance beyond the sideway collapse performance level.