T型钢连接梁柱节点抗火性能试验研究

EXPERIMENTAL STUDY ON THE FIRE PERFORMANCE OF STEEL BEAM-COLUMN T-STUB JOINTS

为研究T型钢连接梁柱节点的抗火性能及破坏模式,使用垂直抗火试验炉,采用恒载升温方式,对4个十字形足尺钢框架T型钢半刚性节点进行抗火试验。试验主要考察T型钢厚度、高强螺栓直径和楼板等因素对节点抗火性能的影响。试验过程中对节点的温度发展和变形情况进行测量,并对钢梁的位移-时间曲线进行分析。结果表明：火灾下T型钢节点的破坏模式主要取决于T型钢和高强螺栓间的相对承载力,承载力相对弱的部分将先发生破坏;混凝土楼板可以较大幅度地提高节点的抗火性能,高强螺栓直径和T型钢壁厚对节点的抗火性能影响不显著;T型钢节点刚度和抗弯承载力在温度升高到500℃~650℃之前无明显变化,之后迅速下降。

To understand their fire resistance and failure mode, an experimental study was performed on four full-scale cross steel beam-column T-stub joints by using a vertical furnace. The load was kept constant during the fire. The key parameters investigated include the thickness of the T-stub, the diameter of the bolts, and the floor on beams. The temperature distribution and the deformation of the T-stub joints in fire were measured through the test. The deformation-curves of the beams are then discussed. The results show that the failure modes of the T-stub joints in fire depend on the relative bearing capacity between the T-stub and bolts, and the damage occurs in the weaker of the two. The floor can greatly enhance the fire-resistance of the T-stub joints, while the thickness of the T-stub and the diameter of the bolts have little influence on the fire performance of the joints. The fire-resistance and stiffness of T-stub joints decrease sharon after 500℃-650℃.