EUROSTEEL 2014, September 10-12, 2014, Naples, Italy BEHAVIOUR OF WELDED REVERSE CHANNEL JOINT COMPONENTS OF I BEAM TO TUBULAR COLUMNS CONECTIONS Luís Magalhães, Carlos Rebelo, Sandra Jordão Polytechnic Institute of Castelo Branco, Technical-Scientific Unit of Civil Engineering, Portugal University of Coimbra, Department of Civil Engineering, Portugal lmmbmagalhaes@ipcb.pt, crebelo@dec.uc.pt, sjordao@dec.uc.pt INTRODUCTION When compared with other steel shapes, tubular profiles show a privileged structural behaviour due to their ability to withstand axial loads, bending in several directions and torsion, besides considerable advantages in terms of maintenance and aesthetics. The welded reverse channel connection is a good solution since it allows for a bolted joint between I beam to hollow column. Furthermore, this type of joint detail has a reasonable construction cost, is easy to implement and features large ductility through the deformation of the web panel. The fact that, in the past, tubular shapes haven’t been such an obvious choice is due to the fact that joints between tubular shapes or to tubular shapes are either completely welded or difficult and expensive, because there is no access to the inside of the tubular shape. Due to this fact, a lesser effort has been directed to research on these typologies, and less comprehensive methods of analysis or code formulation exists for their design. Eurocode 3 [1] provides some rules for welded connections between tubular profiles, but not for bolted connections. However, due to its strategic importance, this topic has had several significant contribution in the last decade. Among those some research initiative from the “Comité International pour le Développement et l’Étude de la Construction Tubulaire” CIDECT stands out, aiming at the development of an unified design approach for steel joints by extending the field of application of the Eurocode 3 component method [2]. 1 OBJECTIVES The main purpose of this investigation is the characterisation of the nonlinear cyclic behaviour of steel joints between I profile beams to hollow section columns with welded reverse channel. In this paper a comparison is made between experimental tests and numerical finite element model results. The main focus will be on the results concerning the strength, stiffness and rotation capacity of the main components of the reverse channel joining detail, i.e. web face in bending, flanges panels in shear, compression and tension. In the experimental program the characteristics of the nonlinear behaviour of the principal reverse channel components is assessed by means of bending tests (monotonic and cyclic). The parameters which have been varied in the tests are the geometry of the loaded area and the dimensions of the flanges and web of the U shaped element. The numerical models are developed with the software LUSAS and calibrated with the results from the experimental tests. 2 EXPERIMENTAL INVESTIGATION 2.1 Parametric range The prototypes are formed by the reverse channel (two flange plates welded to one web plate with holes for bolted to end plate beam). The steel grade is S275. The configurations selected for the experimental tests correspond to a parametric variation on the factors with major influence on the structural behavior of the reverse channel. These parameters, identified in the schematics of Fig. 1, are the thicknesses and width of the web and flanges, the distance between bolts in the same row and the geometry of the end plate. The dimensions of the prototypes are listed in Table 1.