Numerical Modelling and Performance Assessment of Concentrically Braced Steel Frames

A series of nonlinear dynamic analyses are being carried out to improve understanding of the behavior of conventionally braced and buckling restrained braced steel frames, devise loading protocols for experimental assessment of braced frames, and to identify improved performance-based design and analysis procedures. This work extends earlier work by Uriz by updating the edition of the building code used to design the structures being analyzed, and the configuration of the structure is altered from a stacked chevron arrangement to one where the braces are arranged as a double story X. Initial results are presented herein for three-story tall special concentric braced frame (SCBF) structures designed by others in conformance with two recent design guidelines. A variety of results are presented to assess likely behavior for different seismic hazard levels in terms of roof displacement, interstory drifts, residual story displacements, and floor level accelerations.