冷弯薄壁双肢C型钢十字形节点抗震性能

Seismic behavior of cold-formed double C steel cross-shaped joint

冷弯薄壁双肢C型钢背靠背加垫板是一种新的组合截面形式,对该截面形式的十字形节点进行有限元数值模拟,分析节点板厚度、C型钢梁厚度和高度、螺栓间距等参数对节点的滞回性能、骨架曲线、延性、耗能能力、刚度退化的影响,发现C型钢梁截面高度、厚度以及节点板厚度的变化对双肢C型钢十字形节点的抗震性能影响较大。C型钢梁厚度增加,节点的抗震性能会有明显的提高。C型钢梁截面高度变大,节点的承载能力和初始刚度会提高,但延性和耗能能力会减弱。节点板厚度大于12mm时,该类节点的受力性能几乎不变化,但初始刚度会增加;节点板厚度小于10mm时,节点域的协同受力和变形能力较强,但初始刚度和承载能力较弱。分析表明:该类节点具有较高的承载能力,属于典型的半刚性节点。

The paper focuses on a new composite section,namely the double C steel with plate.The finite element numerical simulation is performed on the cross-shaped joints of composite section.The influence of the gusset plate thickness,the web height and thickness of C steel beam,and spacing of bolts on the cross-shaped joints included hysteretic curve,skeleton curve,ductility performance,energy dissipation performance,and stiffness degradation is analyzed.It is found that the web height and thickness of C steel beam and gusset plate thickness has a great influence on the seismic performance.When the thickness of the C steel beam is increased,the seismic performance is significantly improved.The bearing capacity and initial stiffness of the joints are obviously improved after increasing the height of the C steel beam,but the ductility and energy consumption capacity is weakened.The force performance of the joints would hardly change after the gusset plate thickness is greater than 12 mm,but the initial stiffness will increase.The joint force and deformation capacity of the gusset plate and the joint would be stronger when the slab thickness is less than 10 mm,but the initial stiffness and bearing capacity is weak.The analysis in this paper shows that this type of joint has a high carrying capacity and belongs to semi-rigidjoint.