徐善华 孙建设 聂彪

摘   要：研究了锈蚀对冷弯薄壁C形钢轴压短柱承载性能的影响. 通过板材单调拉伸试验，研究了锈损冷弯薄壁钢板材的力学性能退化规律;通过对5根锈损C形钢短柱进行轴压试验，分析了其破坏模式、变形特征和承载力，并讨论了锈损C形钢轴压短柱极限荷载的计算方法. 研究结果表明：锈损板材屈服平台变短甚至消失，屈服强度随锈蚀率的增大呈线性下降趋势;锈损C形钢轴压短柱的破坏模式为腹板局部屈曲，局部屈曲多发生在腹板最薄弱处;极限荷载随着平均厚度损失率的增大呈线性下降趋势;考虑钢材力学性能退化并利用厚度折减修正的有效宽度法和直接强度法均能较好地预估锈损C形钢轴压短柱的极限荷载，但修正后的直接强度法更接近试验结果，修正后的有效宽度法则偏于保守.

关键词：锈损;冷弯薄壁C形钢;轴压;短柱;极限荷载

中图分类号：TU392.1;TU317.1                   文獻标志码：A

Experimental Investigation on Corroded Cold-formed Thin-walled

C-shaped Steels Short Columns under Axial Compression

XU Shanhua1，SUN Jianshe1，2，NIE Biao1

（1. School of Civil Engineering，Xian University of Architecture and Technology，Xian 710055，China;

2. Shandong Province Metallurgical Engineering Co Ltd，Jinan 250101，China）

Abstract：This paper studies the influence of corrosion on the bearing capacity of cold-formed thin-walled C-shaped steel short columns under axial compression. Through the monotonic tensile test of the plate，the mechanical property degradation law of the corroded cold-formed thin-walled steel plate was studied. Five corroded cold-formed thin-walled columns were subjected to axial compression test. Failure mode，deformation characteristics and bearing capacity of the columns were analyzed. The calculation method of the ultimate load was discussed. The experimental results show that the yield platform of corroded steel becomes shorter or even disappears，and its yield strength decreases linearly with the increase of corrosion rates. The failure mode of the corroded C-shaped short column under axial compression is local buckling failure of the web，but local buckling occurs mostly at the weakest part of the web. The ultimate load decreases linearly with the increase of the average thickness loss rate. The effective width method and the direct strength method，considering the degradation of the mechanical properties of the corroded steel and thickness reduction，can predict the ultimate load of the C-shaped steel short columns under axial compression. However，the modified direct strength method is closer to the test results，and the modified effective width method is more conservative.

Key words：corrosion;cold-formed thin-walled C-shaped steel;axial compression;short column;ultimate load

相比热轧钢，冷弯薄壁型钢具有轻质高强、抗震性能好、截面设计灵活、受力合理且易于工业化等优点而被广泛应用[1].  但因其多为开口截面且壁厚较薄、板件宽厚比较大，稳定性问题更为突出，因此对冷弯薄壁型钢的研究主要集中在稳定性和屈曲理论等方面[2-3]. 长期暴露在工业环境中的钢材不可避免地产生一定程度的锈蚀，锈蚀不仅导致钢材截面面积损失和材料性能退化，而且降低结构的承载性能[4-7].

目前，关于锈损钢材力学性能和……