EVALUATION OF SEISMIC BEHAVIOR OF STEEL FRAMES EQUIPPED WITH OFF CENTER BRACING AND EBF BRACING UNDER THE NEAR AND FAR FIELD EARTHQUAKES

In order to solve the problem of low stiffness in the framing system, as well as the problem of low formability in a frame with a coaxial bracing, Popov proposed a non-axial brace. By choosing the right amount of exit from the center, the system is sufficiently hard and through supplying the shear of the interface beam, the system's ductility is supplied. This system has a good ductility, but in order to ensure its plasticity, the interface beam, which is one of the main elements of the structure, surrenders, causing serious damage to the ceiling and difficult to repair after the earthquake. Due to fixing problems, the gateway system has been developed. In this study, an evaluation of seismic behavior of steel frames equipped with OFF Center Bracing and EBF bracing under the near and far field earthquakes has been investigated. For this purpose, the analysis of nonlinear time histories has been performed under seven seismic records of the near and far field in ABAQUS software on 4, 8 and 12st frames equipped with off center and EBF bracing, shown in Figure 1.

Keywords:

Nonlinear dynamic analysis , Off center bracing , EBF bracing , Near and far field earthquakes