Investigating seismic behavior of a modified widened flange beam-column connection in SMRF utilizing experimental, numerical and hybrid simulation

This manuscript presents the seismic performance of a modified widened flange beam-column connection in a special moment-resisting frame (SMRF). The beam-column connection has been modified by two cover plates welded to the top and bottom flanges of the beam and investigated under earthquake acceleration. One-story one-bay special moment resisting frame with an increased beam flange at the vicinity of column was analyzed in accordance with the Iranian Code of Practice for Seismic Resistance Design of Buildings (Standard 2800). Experimental investigation was carried out in which a cyclic displacement history was applied. Numerical finite element analysis was carried out using ABAQUS and its results validated by experimental test results. A hybrid simulation was conducted utilizing OpenSees as the finite element software, OpenFresco as the middleware and LabVIEW as data collector and actuator motion controller. Results comparison of three above mentioned methods (experimental test, numerical analysis and hybrid simulation) indicate that the hysteresis curves are in great compatibility with each other. As expected, results demonstrate that the yielding occurred immediately beyond cover plates at arc shaped areas of beam. On the other hand, the experimental and numerical results show that the specimen reached at least 0.07 rad drift angle before experiencing strength degradation. Furthermore, parametric studies on 'c' and 'R' which are two key parameters of modified widened flange beam represent that for a constant dimensions of cover plate, increasing 'c' and decreasing 'R' will reduce plastic strain and stress demands in beam.