Development of Eccentrically Interconnected Braced Frame (EIC-BF) for seismic regions

Abstract

This study aims to develop an Eccentrically Braced Frame (EBF) system, which is so called Eccentrically Interconnected Braced Frame (EIC-BF), by proposing an innovative Structural Fuse (SF) using a very thin mid-height gusset plates with specified details for seismic regions. In the proposed structural system, as a low damage or repairable system, the mid-height gusset plate, as a replaceable centric shear link that connects four eccentric brace segments, behaves as a SF so concentrates most of large deformation and stress demand and dissipates the large amount of energy imposed by lateral loading. In order to investigate the effect of the proposed SF with the specified details, i.e. mid-height gusset plates with proposed details, on the seismic behavior of EIC-BF, nine three-fourth scale cyclic experiments were conducted. This research describes the results of the experiments elaborately and evaluates the cyclic responses of the studied EIC-BFs with respect to their utilized details. The results show that establishing the specified details and design parameters including eccentricity value of braces at mid-height gusset plate, mid-height gusset plate thickness and the stiffener configuration at mid-height gusset plate improves the seismic performance of EIC-BF in term of story drift angle by up to 32% as well as reduces the considerable pinching in cyclic response; while prevents main structural elements including beam, columns and braces from undergoing inelastic behavior.