The Effect of BRB and CBF Braces on Seismic Behavior of Steel Structures under Near Field Earthquakes

Buckling Restrained Brace (BRB) has the ability to wear and absorb energy well. The aim of this study was to obtain the results of dynamic behavior of metal structures and seismic system with CBF braces and compare them with the results of steel structures equipped with BRB bracing with two different cross sections due to near field earthquake and better building control. Considering that our country is located in an earthquake-prone region, it is inevitable to take into account the considerations related to near-fault earthquakes in the design of the standard earthquake spectrum. In this paper, two 5 and 10 level steel structures are modeled in Etabs software. This software was selected for the initial design of structural elements and then using Perform-3D software, their seismic behavior in near field earthquakes was evaluated with two braces BRB and CBF. The result of this study shows that structures with non-buckling braces have high energy absorption and absorption and have the same behavior in pressure and tension, which causes maximum and more base shear as well as better performance than Structures with CBF bracing. They also control the movement of the building due to its high stiffness. Finally, if the metal cross-sectional area of the BRB braces is higher, the performance of the structure and displacement will be better controlled. Finally, energy consumption by this brace, as mentioned above, responds to equal traction and pressure, like a damper.