Research On The Hysteretic Behavior Of Tubular Web Reduced Beam Section Connection

Reduced beam section connection is an effective way for the movement of plastic hinge, mainly including the dog bone style weakened beam flange and opening style weakened beam web. Although this two weakening ways are both able to force the plastic hinge away from the column face, the shear and compressive bearing capacity would be decreased, leading to the decrease of the planar beam stiffness and the resistance capacity of bending and torsion. The corrugated web steel have many advantages, such as high out-plane stiffness, high shear buckling strength and superior anti local buckling performance. Thus, this paper unifies the advantages of the traditional reduced connections and the corrugated webs, and proposed a new reduced connection by replacing the beam web near the connection with the round tube, named tubular web reduced connection(new reduced connection for short). In this paper, Using ANSYS to model the new reduced connections under beam end cyclic loading, the results of low cyclic loading test and analysis were compared and validated, illustrating the effectiveness of finite element. Comparative analysis of the new reduced connections and the traditional reduced connections was performed. And parameter analysis was carried out for new reduced connections to study their influence on the hysteretic performance, including the thickness of the circular tube, the distance of tube center to column flange, the tube diameter, the circular tube material category and the pipe shape. Studies show that:(1) traditional reduced connection and new reduced connection both can realize the movement of plastic hinge, but compared to the traditional reduced connection, new reduced connection significantly slowed down the out-plane flexural-torsional buckling during later load stage, and have higher stiffness, bearing capacity and ductility.(2) bearing capacity and ductility of new reduced connection increased with the thickness of the circular tube, the distance of tube center to column flange and tube material strength increased, decreased with the increase of the tube diameter.The circular tube thickness is suggested to be 0.55~1.0 times of the beam web thickness, the distance of tube center to column flange to be 0.5 ~ 0.8 times of the beam height, and the tube diameter is suggested to be 0.7~0.8 times of the beam flange width. It is also suggested that the circular section steel tube whose material grade is higher than the beam and column section should be adopted.