方钢管焊接T型节点轴向静力性能研究

The static performance of axially loaded,square tubular T-joints

采用试验实测的方法,研究不同支管与主管宽度比(β)方钢管焊接T型节点的静力承载机理和破坏形态,并对节点的变形特点、应变分布、荷载-位移曲线进行分析.结果表明:方钢管焊接节点在支管轴向压力作用下的延性较好,试件在破坏前有充分的塑性发展;β=0.4时试件发生主管表面屈服破坏,β=0.8时试件发生表面屈服与侧壁屈曲破坏,β=1.0时试件发生主管弯曲屈服破坏;节点的轴向承载力和初始刚度随着β的增大有显著提高,β=1.0和β=0.8试件比β=0.4试件的承载力分别提高156%和310%,初始刚度则分别提高68.6%和94%;主管两端固定的约束条件对β≤0.8试件的承载机理及破坏形态影响较小,但引起β=1.0试件在节点区域破坏之前发生主管破坏.

An experimental study was conducted to gain an understanding of the static perform- ance of a square, tubular welded T-joint under braced axial loading. The deformation charac- teristics, strain distribution, and load-displacement curves of the specimens were analyzed. The strength mechanics and failure modes were then evaluated. It appears that the welded square tubular specimens have good ductility under braced compression and exhibit full devel- opment of plastic deformation before joint failure. The joint failed from yield of the chord flange when fl=0.4, from a combination of web buckling and flange yielding when fl=0.8, and from the bending and yielding of the chord when fi= 1.0. The axial strength and initial stiffness of the joints increase significantly when β was increased from 0.4 to 0.8 or 1.0. The fixed restraint of the chord ends influenced the performance and failure of the β≤40.8 specimens only slightly while causing the chord of β= 1.0 specimens to fail before damage was observed in the joint zone.