Safety assessment of steel buckling restrained braced frames

The experience of recent earthquakes like those occurred in Kobe and Landers and those earthquakes occurred in Iran as Tabas and Bam earthquakes have shown that structures are vulnerable against near-field earthquakes and lateral displacement and damages to steel structures has always been of serious concerns for structural engineers .Lateral displacement and damages of steel structures has always been a cause of serious concern for structural engineers. This article aims to evaluates the safety of Buckling Restrained Braced frame (BRBs) under nonlinear incremental analysis. Due to the uncertainty in seismic demand and capacity, this study uses seismic reliability-based probabilistic structure in order to have the function of the Buckling Restrained Braced system .To evaluate the seismic capacity, design of steel structures with buckling restrained brace (BRB) was carried out by the SAP 2000 software using nonlinear incremental dynamic analysis (IDA) .The results of this study show that low-rise Buckling Restrained Braced steel structures under near-field earthquakes are likely to less possibility damage in the peak acceleration lower than (1g) compared to similar high-rise structures. The expected performance level of the standard 2800 (life safety) was not also met in high-rise structures. In sum, Buckling Restrained Braced system on the performance levels of Collapse Prevention and Immediate Occupancy are safer against near-field earthquakes in the low-rise frames than high-rise ones.

کلیدواژه ها:

Buckling Restrained Braced ، incremental dynamic analysis ، fragility curves