Structural behaviour of combined flange-cleat and gusset plate connection for cold-formed steel double channel sections

Abstract

The use of cold-formed steel in light steel framing design is becoming popular in Industrialized Building System, because the construction activities on-site are reduced and make it faster, cleaner and to a certain aspect safer if compared to the use of traditional building system. The lightness of the structures may reduce the severity of building collapse. However the beam-to-column joints in IBS is am major concern especially in case of seismic behaviour. These joints behaviour for cold-formed steel primary structures, particularly the partial strength semirigid beam-to-column connection has not been studied in depth. This paper presents the isolated joint test on combined flange-cleat and slip-in gusset plate connections with 6 mm steel angles and plates. Two cold-formed lipped channel sections were placed back-to-back to form beam and column members. Three specimens with the depth of beam ranging from 150 mm to 250 mm were tested. From the experimental results, it is observed that the ratio of moment resistance of joint to the moment resistance of the connected beam increases in the range of 0.76 to 0.94. The rotational capacities of the joints exceed 30 mRad. The rotational stiffness achieves 646 kNm/rad to 2228 kNm/rad. It is concluded that the proposed connections are classified as partial strength connection and suitable for semi-continuous construction that enhanced the seismic design by providing ductile behaviour.