新型薄壁方钢管梁柱节点试验研究及影响参数分析

EXPERIMENTS AND INFLUENCE PARAMETERS ANALYSIS OF NEW TYPE OF THIN-WALLED SQUARE STEEL TUBE BEAM-COLUMN JOINT

薄壁方钢管梁柱节点采用直接焊接方式连接容易诱发节点区域板件脆性断裂,降低节点塑性变形能力。从分散焊缝角度出发,减少对柱管壁施焊次数,提出一种新型连接方式。将这种新型节点与直接焊接方式(普通节点)进行试验对比,从破坏模式、滞回耗能和延性等方面考察新型节点的特点,然后采用有限元模型进一步研究几何参数的改变对新型节点力学性能影响。结果表明:新型节点的承载力相对普通节点较小,但延性及耗能能力均较强;方钢管柱及C型钢梁的厚度对节点的滞回曲线形状影响较小,但承载力、初始刚度及耗能能力均随着相关厚度的增加而增加;方钢管梁厚度的改变对节点滞回曲线和承载力影响较小,对初始刚度值影响较大;C型钢梁的高度与相对位置的改变对节点滞回曲线、承载力及刚度均有较为显著的影响,且改变滞回曲线捏拢现象。

A direct welding connection way is usually used for the thin-walled steel tube beam-column joint, it will lead to a brittle fracture in the joint region and also reduce the node plastic deformation ability. Based on the way of scattering the welding, and reduce the welding number of column, a new connection way was proposed. It was contrasted XJD node with JD node through experiment. It was examined XJD＇ s characteristics by the damage way of node, hysteretic energy and ductility. It was also studied the changes of geometric parameter that affect mechanical property through finite element model. The results show that from the experimental study, it can be found that the XJD node has less bearing capacity, but has more ductility and energy dissipation capacity than the JD node. In the parametric analysis, the thickness of the square steel tube column and the C-shaped steel beam has less affect on the shape of hysteresis curve, but the bearing capacity, initial stiffness and the energy dissipation are increased with the increase of these values. The change in thickness of the square steel tube beam has less affect on the node hysteresis curve and the bearing capacity, but has greater impact on the value of the initial stiffness. The changes of the C-shaped steel beam and the relative position of the square steel tube beam and C-shaped steel beam have a significant impact on hysteresis curve, carrying capacity and the initial stiffness. It can also change the pinching of the hysteresis curve.