Cyclic Response of Reduced Beam Section

Abstract

Recent earthquakes have shown that steel moment frame (SMF) with weld connections are so brittle. According to the studies conducted, great damages are due to the cracking of the weld between the beam flange and the column face and inducing concentrated stresses in this area. A natural way to solve the problem is to reduce the ductility demand on the welded areas by reducing the stress concentration level. A useful approach to reduce the stress concentration at the panel zone could be the use of reduced beam section (RBS). A portions of the beam flanges are trimmed away in the region adjacent to the beam-to-column connection (Han et al. in J Constr Steel Res 70:256–263, 2012) [1]. The RBS can be viewed as a ductile fuse that forces the formation of the plastic hinge away from the joint so that much of ductility demand on beams may result from the RBS instead of the welded beam-to-column interface. RBS connection is widely investigated and used in US, Japan and Europe. In this study moment connections with different shape of reducing beam flange have been modeled using ANSYS and compared with each other during cyclic behavior. The sloped moment connection with best configuration is analyzed to find the cyclic response of the connection (Shen et al. in Eng Struct 22:968–983, 2000) [2].