Shear capacity of the cold-formed steel beam to column welded moment connection using clip-angle and flange-cleat

Abstract

The current research endeavours to evaluate the shear performance of the cold-formed steel (CFS) welded moment connection between beam-to-column with 36 laboratory tests. The web portions of the beam and column were connected by CFS welded clip-angle to form a CFS welded shear connection. Subsequently, it is converted into a welded moment connection by including a flange cleat between the flange portions. The shear capacity of the welded shear connection increases by an average of 67% after the inclusion of flange cleats, which is quantified using a performance ratio variable. This research presents two shear equations for the CFS welded moment connection (i) a new empirical shear equation; (ii) a new shear equation representing the shear strength of the moment connection as a function of the shear strength of the shear connection. The variability of the shear performance of welded moment and welded shear connections is expressed with force versus displacement plots and failure modes of the clip angles. The failure modes observed in the clip-angle in both welded moment and welded shear connections are (i) Local buckling and (ii) Distortional buckling. The shift in failure modes of some of the clip-angle in the WM connection (Local buckling) and the WS connection (Distortional buckling) indicates the effectiveness of flange-cleat in resisting due to free twisting of the beam because of load offset from the shear center. The design factors were also determined for the LRFD, LSD, and ASD methods by performing reliability studies.