Performance evaluation of concentrically braced frames equipped with pure bending yielding damper

Abstract

In this paper, the seismic performance of steel concentrically braced frames (CBFs) equipped with the newly proposed pure bending yielding (PBY) damper is examined. The PBY damper, developed by the second author and his co-worker, is a type of steel damper that converts axial force to pure bending in a concentric brace. This is done through steel plates installed perpendicular to the brace axis that are resting on rollers placed symmetrically to produce four-point bending. For the sake of evaluation, 4, 8, and 12-story buildings composed of CBFs are studied. Results of experiments on the same damper are used for verification. The pushover analysis of the CBF systems shows that the systems equipped with the proposed damper are superior to the special concentric braced frames regarding ductility and stability in the nonlinear area of behavior. Besides, nonlinear dynamic analysis under 11 consistent and scaled ground motions exhibits that the residual drifts of the proposed system are less than 1% which is small enough to save nonstructural elements. All of the other structural elements, except for the PBY dampers, are shown to remain in the elastic region free of any seismic damage that confirms the suitable seismic behavior of the system.