拉-弯-剪组合作用下法兰连接方钢管柱受力性能研究

为研究多高层钢结构柱连接在拉-弯-剪组合作用下的受力性能，对4个不同法兰板厚度的法兰连接柱进行了足尺模型试验和有限元分析，并通过有限元模型分析了轴拉比对法兰连接柱性能的影响。结果表明：随着法兰板厚度增大，连接柱的侧向刚度和水平承载力增大，受拉区法兰接触面翘力减小；在拉-弯-剪组合作用下，法兰中性轴位置在受压侧第二排螺栓附近，且随着法兰板厚度的增大，中性轴位置由法兰受压区逐渐向其几何中心移动。轴向拉力对法兰产生的作用效应与水平荷载产生的作用同向。轴向拉力降低了法兰连接柱的水平屈服荷载，法兰转角随着轴拉比的增大而增大。

Bearing performance of bolted-flange connection of square steel tubular column under tension-bend-shearing combination

To study the load carrying behaviour of column connections in multi-and high-rise steel structures under the combination of tension, bending moment and shear, full-scale model tests and finite element analysis were performed on four bolted-flange connection specimens with different flange thicknesses. The influence of axial tension ratio on the performance of the connection was analyzed by finite element analysis. The results show that the lateral rigidity and horizontal bearing capacity of the connection increase, and at the mean time the prying force between the flange surfaces of the connection tension zone decreases as the flange thickness increases. Under the combination of tension, bending moment and shear, the neutral axis of the flange is near the second row of bolts on the compression side, and the position of the neutral axis gradually moves from the compression zone to the centroid of the flange as the flange thickness increases. The action effects of the axial tension and the horizontal force led on the connection are in the same direction. The horizontal yield load of the connection is reduced due to the existence of the axial tension, and the flange rotation angle increases with increase in axial tension ratio.