Seismic response of steel structures with buckling restrained braces with and without viscous damper under near and far fault earthquakes

The appreciation of buckling restrained brace systems has increased over the past two decades. The relatively high energy losses and optimal ductility are the characteristics of this system and the l displacement control as well as the residual displacement is challenging issues under the earthquake. In this paper, the behavior of simple frame structures with buckling restrained braces with and without viscous dampers in intermediate and high rise buildings under the influence of   near fault and far fault records was investigated. Initially, the structures were analyzed using a spectral dynamical analysis method and valid regulations. Then nonlinear model of structures was developed in PERFORM-3D software and nonlinear time history analysis was performed. The response of the structures was examined and compared. The results show that the inter-story relative displacement in the structure with buckling restrained braces and fluid damper under far fault earthquakes compared to without damper case decreases by about 30%, with the corresponding value under the near-earthquake of about 15%. The maximum resistive force of the liquid damper appears at the moment of the most inter story relative velocity, and this is evident in the buckling restrained brace in the most inter story relative displacement. Due to the phase of relative inter story displacement and relative inter story velocity, the use of a hybrid system can lead to better control of structural responses.