| Title |
Experimental Study on Elasto-Plastic Behaviors of Composite Beam with Slit around Column |
| Authors |
Yang Il-Seung ; Hwang Sung-Chul ; Lee Sang-Joon |
| Keywords |
Composite Beam ; Beam-to-Column Connection ; Slit ; Channel-shaped Shear Connector ; Local Buckling |
| Abstract |
Composite beam can increase the flexural stiffness and strength under the positive bending moment compared with structural steel beam, but at the same time it brings about a large difference in stiffness and strength in the positive and negative bending moment. It also tends to fracture at the bottom flange, which was observed in 1995 Kobe earthquake. Therefore, a new composite beam is proposed to solve such problems which is characterized by the slit in the concrete slab around the column. The seismic behavior of the new composite beam system was studied through reversed cyclic loading on several beam-to-column assemblies and related analytical investigations in the first phase. It showed that the proposed system could inherit high flexural stiffness from general composite beam and large beam rotation capacity from structural steel beam. In the second phase which will be discussed in this paper, three additional experiments were planned so as to obtain practical design information on the details around the slit and the arrangement of shear studs. The general composite beam showed fairly good strength and stiffness under the positive bending moment. However the bottom flange of the beam showed serious fracture due to large strain reversal brought from the composite action. The new composite beams having a slit showed large ductility, even if channel-shaped shear connector is used instead of shear studs. It also showed enough flexural stiffness and good restraint for local/lateral buckling of the beam. |