论文部分内容阅读
为了解平面X形圆钢管混凝土节点的平面外受弯性能,分别对4个主管填混凝土和4个支管填混凝土的平面X形圆钢管节点进行支管平面外弯矩作用下的试验研究。考察了支管、主管分别填混凝土2种情况下节点的破坏模式和应力分布,并分析了钢管内混凝土对节点平面外抗弯刚度及承载力的影响。试验中支管填混凝土节点出现了主管塑性、支管局部屈曲和支管受拉侧焊缝或热影响区管壁开裂的破坏模式,主管填混凝土节点则发生了支管局部屈曲及支管受拉侧焊缝开裂破坏。主管填混凝土节点与支管填混凝土节点相比,由于主管内填混凝土对于主管管壁的局部变形起到明显的约束作用,明显提高了主管的径向刚度,增大了节点的平面外抗弯刚度。实测节点承载力与欧洲规范计算的空钢管节点理论承载力比较表明,主管内填混凝土能极大提高节点平面外受弯承载力,最大可提高132%;支管内填混凝土可使节点平面外受弯承载力最大提高60%。
In order to understand the out-of-plane bending behavior of X-shape CFST joints, the experimental study of the plane X-shaped circular steel tube joints with four main tube-filled concrete and four branch-tube filled concrete under buckling moment were carried out. The damage modes and stress distributions of the joints under two kinds of concrete filled with concrete were investigated. The effects of concrete in the steel pipe on the flexural rigidity and bearing capacity of the joints were analyzed. In the experiment, the plastic deformation of main pipe joints, the local buckling of branch pipes and the failure mode of pipe wall cracking by heat-affected zone or weld zone occurred in the branch pipe joints. Local buckling of branch pipe and cracking of the welded side of branch pipes occurred in charge of concrete-filled joints damage. In charge of concrete filled joints compared with the branch filled concrete joints, as the main filling of the main pipe wall for local deformation played a significant constraint, significantly increased the director of the radial stiffness and increase the out-of-plane bending stiffness . The comparison of the measured bearing capacity with the theoretical load-bearing capacity of the hollow steel pipe joints calculated by the European Code shows that in-charge concrete can greatly increase the out-of-plane bending bearing capacity, which can be increased by 132% at the maximum. The concrete filled in the branch pipe can make the out-of- Bending capacity up to 60%.