| Title |
Hysteresis Behavior for CFT Square Column-to-Beam Partially Restrained Composite Connections |
| Authors |
Choi Sung-Mo ; Park Su-Hee ; Park Young-Wook ; Kim Jin-Ho |
| Abstract |
This study is on the development of an improved detail of partially restrained CFT square column-to-beam connection and the evaluation of its hysteretic performance under the repeated loading. The connection is designed to prevent the brittle failure at the bottom of the connection due to the composite effect of concrete slab and steel beam and simplify its fabrication process. The suggested connections are the welded bottom beam flange connection(S-2) and its improved type with the dog-bone shape in the bottom flange of the beam(S-3). These two types are compared with the existing partially restrained composite connection of bolted seat angle connection(S-1). To evaluate their performance, three specimens were fabricated in the actual size and tested under the cyclic loading. As the test results, the welded bottom beam flange connection had about 85% of stiffness of steel beam, similarly to the bolted seat angle connection and behaved as partially restrained connection. The specimens of the supposed connection types failed at the bottom of weld zone. It obtained the capacity and deformational ability equivalent to the full-plastic moment through the anchor inside the steel tube, and the capacity didn't drop abruptly, while it reached the plastic rotation angle of 0.04rad. Consequently, it can be said that the suggested connection exhibits more ductile behavior than the bolted seat angle connection. |