锈蚀脚手架钢管轴压稳定性试验研究

为研究锈蚀对扣件式脚手架体系中钢管立杆稳定性的影响，通过对不同锈蚀龄期的钢管进行表面形貌测试，分析锈蚀对钢管内、外壁表面形貌的影响；通过锈蚀钢管材料单调拉伸试验，探讨锈蚀条件下钢材力学性能的退化规律；基于锈蚀钢管的轴心受压试验结果，提出锈蚀钢管立杆稳定性的计算模型。结果表明：随着钢管失重率的增加，钢管表面坑蚀分布由独立蚀坑向溃疡状蚀坑群发展，外壁坑蚀率、算术平均高度和均方根高度均不同程度地高于钢管内壁；锈蚀钢材表面随机分布、大小不一的蚀坑会导致钢材强度与塑性变形能力下降、塑性变形能力劣化更明显；不同锈蚀程度的钢管轴压破坏模式均为整体弯曲失稳，锈蚀钢管的极限荷载随失重率的增加线性下降，峰值荷载对应的轴向位移值逐渐降低。

Experimental study of axial compression stability of corroded steel tube in scaffold

To study the effect of corrosion on the axial compression performance of the upright tube of steel tubular scaffold with couplers, the surface morphology of steel tubes with different corrosion ages was tested to analyze the influence of corrosion on the surface morphology of the inner and outer walls of steel tubes, and the degradation law of mechanical properties of corroded steel was discussed through the monotonic tensile test of corroded steel tube. The calculated formula for the stability of the corroded steel tube was proposed through the results of the axial compression tests. The results show that the distribution of pit corrosion on the surface of steel tube develops from independent pits to ulcer-like pit groups with an increase of the quality loss rate of steel tube. The pit corrosion ratio, the average arithmetic height, and the root mean square height of the outer wall are higher than those of the inner wall in varying degrees. Randomly distributed and different sizes of pits will cause the decrease of the strength and plastic deformation ability of the steel. Compared with the decrease in strength, corrosion has a more severe impact on the plastic deformation ability of steel. The axial compression failure mode of steel tubes with different corrosion degrees is the overall bending instability. As the mass loss rate increases, the ultimate load decreases linearly, and the axial displacement value corresponding to the peak load point decreases gradually.