COMPDYN 2011 III ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis, V. Plevris (eds.) Corfu, Greece, 25–28 May 2011 NEW METHOD FOR PROVIDING FAVORABLE SEISMIC PERFORMANCE IN PANEL ZONE REGIONS OF MOMENT RESISTING CONNECTIONS OF BEAMS TO FLANGED CRUCIFORM COLUMN SECTION Rasoul Mirghaderi 1 , Mohammad Motallebi 2 1 Assistant Professor, School of Civil Engineering, University College of Engineering, University of Tehran, Tehran, Iran e-mail: rmirghaderi@ut.ac.ir 2 Graduate Student, School of Civil Engineering, University College of Engineering, University of Tehran, Tehran, Iran mmotallebi@ut.ac.ir Keywords: Flanged Cruciform Column, Moment Resisting Connection, Panel Zone Region, Inclined Vertical Plates, Accordion Load Path. Abstract. It is common in structural design to use separate load resisting system in each principal direction of the buildings. In these systems, columns which are located in the inter- section of two perpendicular axes play a significant role in resisting gravitational loads as well as seismic demands in both directions. In seismic design, it is necessary to use practical- ly similar sections for columns in both axes. Flanged cruciform sections, having relatively similar behavior about both principal axes, seem to be a proper choice for this purpose. They have apparently much simpler fabrication process in beam-column joint regions than the closed box sections. Since having two perpen- dicular webs, usage of common doublers plates leads to discontinuation of load paths and is not applicable. On the other hand, the local increase in the web thickness is not possible in the cruciform sections built using hot rolled sections. Therefore, it is necessary to consider an alternative path to provide a suitable performance in the beam column joints. In this paper, by means of nonlinear numerical analysis, influences of connection details on the behavior of flanged cruciform column are studied. Since dynamic behavior of flanged cruciform column is depended on the connection behavior, in order to detect column behavior, it is subjected to monotonic and cyclic lateral displacement loading. Analysis shows connec- tion details play a significant role in moment distribution of column parts. In addition, a new load path is suggested to provide a proper way to transfer panel zone's shear force and its effectiveness in improving behavior of flanged cruciform column is presented.