Tubular Web Reduced Beam Section (TW-RBS) connection, a numerical and experimental study and result comparison

  • Zahrai, Seyed M. (School of Civil Engineering, College of Engineering, The University of Tehran) ;
  • Mirghaderi, Seyed R. (School of Civil Engineering, College of Engineering, The University of Tehran) ;
  • Saleh, Aboozar (Department of Civil Engineering, Islamic Azad University Professor Hesabi branch)
  • Received : 2015.05.29
  • Accepted : 2017.01.29
  • Published : 2017.04.10


A kind of accordion-web RBS connection, "Tubular Web RBS (TW-RBS)" connection is proposed in this research. TW-RBS is made by replacing a part of web with a tube at the desirable location of the beam plastic hinge. This paper presents first a numerical study under cyclic load using ABAQUS finite element software. A test specimen is used for calibration and comparison of numerical results. Obtained results indicated that TW-RBS would reduce contribution of the beam web to the whole moment strength and creates a ductile fuse far from components of the beam-to-column connection. Besides, TW-RBS connection can increase story drift capacity up to 9% in the case of shallow beams which is much more than those stipulated by the current seismic codes. Furthermore, the tubular web like corrugated sheet can improve both the out-of-plane stiffness of the beam longitudinal axis and the flange stability condition due to the smaller width to thickness ratio of the beam flange in the plastic hinge region. Thus, the tubular web in the plastic hinge region improves lateral-torsional buckling stability of the beam as just local buckling of the beam flange at the center of the reduced section was observed during the tests. Also change of direction of strain in arc shape of the tubular web section is smaller than the accordion webs with sharp corners therefore the tubular web provides a better condition in terms of low-cycle fatigue than other accordion web with sharp corners.


cyclic behavior;moment resisting steel frames;rigid connection;reduced beam section;Tubular Web RBS (TW-RBS)


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