Experimental and Numerical Investigation on the Moment Rotation Behavior of Cruciform Moment Connections with Reduced Beam Sections

摘要

The unexpected local damage may happen in the beam column connections of steel structures under lateral loads, since the connection is the focal point. Adopting reduced beam section (RBS) is an innovative method to dissipate the energy of such structures since it will enable a plastic hinge to be formed in the beam portion, thus reducing large stress concentration in the connection. Also, the formation of plastic hinge will satisfy the seismic criteria of strong column and weak beam combination. This paper focuses on analyzing the efficiency of cruciform connection fabricated with RBS. The structural components comprise of standard I section beam and column connected through welds. Finite element method is applied and model is created for cruciform connections in which different RBSs are used. The models are validated using experimental analysis applied on the specimen. The monotonic load is gradually applied at the two ends of the beams and moment rotation behavior is established. Similar behavior is studied for the RBS model and double reduced beam section (DRBS) as well. The effective connection stiffness is identified for the different models under consideration. It is observed from the results that RBS and DRBS can sustain large inelastic strains besides limiting stress concentration in the connection.