环口板加强型T型圆钢管节点承载力的试验研究

EXPERIMENTAL STUDY ON BEARING CAPACITY FOR CIRCULAR TUBULAR T-JOINTS WITH COLLAR PLATE REINFORCEMENT

对于圆钢管构件,由于空心薄壁的特点,管件在径向的刚度通常要远远小于其轴向刚度。焊接相贯圆钢管节点中,支管主要承受轴向荷载,从而导致主管要承受径向作用力。此外,节点部位由于曲率不连续而带来很大的应力集中现象。这些原因造成管节点最常见的破坏方式是主管表面靠近焊接部位的局部屈曲或屈服破坏。为了提高管节点的承载能力,通过在主管表面焊接环口板的方式来提高主管在节点部位的径向刚度,进而提高管节点的静力强度。通过对3个T型圆钢管节点试件以及3个采用环口板加固的T型圆钢管节点试件在轴压作用下静力承载力的试验测试,验证了环口板对提高管节点静力强度的效果。试验测试结果表明:由于环口板增加了主管在焊接部位的刚度,从而改变了管节点的破坏方式,将未加固节点在焊缝周围的破坏转移到环口板周围的破坏,可以有效地提高管节点的承载能力。

For a circular tube member, its radial stiffness is generally much smaller than its axial stiffness due to its hollow section and thin wall. In a welded tubular joint, the brace is mainly subjected to axial loading, and thus makes the chord be subjected to radial loading. Furthermore, high stress concentration exists at the joint because the curvature is not continuous. Due to the above reasons, the common failure mode for a tubular joint is the local yielding or buckling on the chord surface near the weld toe. To improve the bearing capacity of a tubular joint, a collar plate is welded around the weld toe to increase the radial stiffness of the chord, and thus to increase the static strength of the joint. Through experimental tests on the static bearing capacity of 3 un-reinforced and 3 collar plate reinforced tubular T-joints under axial compression, the reinforcing efficiency is verified. The experimental results show that the failure mode and the failure position are both changed due to the reinforcement of the collar plate, and the collar plate improves the static strength of the T-joints remarkably.