冷弯薄壁方钢管梁柱加腋节点抗震性能影响参数研究

Influence factor study on the seismic behavior of cold-formed thin-wall square steel tube connections with welded haunch

冷弯薄壁方钢管管壁较薄,焊接节点连接性能较差。加腋节点既提高节点刚度,又能改变节点梁剪力转移机理,迫使塑性铰外移,适合在高烈度抗震设防区推广应用。依据节点试验结果,建立有限元模型,探讨不同加腋件高度、长度和厚度对节点抗震性能的影响。结果表明:1)节点加腋后,塑性铰易在加腋件末端形成;2)随加腋件的高度和长度增加,节点承载力有所提高,滞回性能和延性均有所降低;随加腋件厚度增加,节点刚度增加,但节点承载力有所降低;3)建议加腋件高度和长度取1/4～1/3倍梁宽,加腋件厚度取1～3/2倍钢管梁壁厚。

Because of the thin wall thickness of cold-formed square steel tube, the welded joints have a poor performance. Joint with welded haunch not only improve the stiffness of joint, but also change the beam shear transfer mechanism, forced the relocation of plastic hinge, suitable for use in high-intensity seismic zone application. Based on the joints test results, set up a finite element model to explore the impact of different haunched pieces height,length and thickness on the seismic performance of the joint. The results showed that： 1 ） after welded haunch,the plastic hinge easily formed at the end of haunched pieces;2） with the height and length of haunched pieces increases, the bearing capacity of joint has increased, hysteretic behavior and ductility were decreased;with the thickness of haunched pieces increases, stiffness of the joint increased, but the bearing capacity decreased; 3 ） height and length of the haunched pieces recommended to take 1/4 to 1/3 times the beam width, thickness of the hauncbed pieces take 1 to 3/2 times the wall thickness of steel beams