高强冷弯薄壁型钢卷边槽形截面轴压构件试验研究及承载力分析

对63根屈服强度550MPa高强冷弯薄壁型钢卷边槽形截面轴压构件进行试验研究，分析了构件的屈曲模式和极限承载力，并将参考AISI规范、澳洲规范和北美规范及我国现行行业标准《低层冷弯薄壁型钢房屋建筑技术规程》（报批稿）计算的构件承载力与试验结果进行分析比较。在此基础上，对高强超薄壁型钢卷边槽形截面轴压构件的承载力合理计算模式进行研究。结果表明：高强超薄壁型钢卷边槽形截面轴压构件在宽厚比较大时会出现畸变屈曲模式；采用等效板件方法计算加劲板件有效宽度后，我国《低层冷弯薄壁型钢房屋建筑技术规程》（报批稿）适用于屈曲强度550MPa、厚度小于2.00mm的冷弯薄壁型钢卷边槽形截面构件承载力计算。

Experimental study and load-carrying capacity analysis of high-strength cold-formed thin-walled steel lipped channel columns under axial compression

Load-carrying capacities of 550MPa high-strength cold-formed thin-walled steel lipped channel columns subjected to axial compression have been studied through the experimental results of 63 specimens in this paper in order to analyze the buckling modes and ultimate load-carrying capacities. Test results have been compared with the theoretical results calculated by ‘Specification for the design of cold-formed steel structural members’(AISI:1996), ‘North American specification for the design of cold-formed steel structural members’(AISI NAS:2001), ‘Cold-formed steel structures’(AS/NZS 4600:2005), and Chinese  ‘Technical specification for low-rise cold-formed thin-walled steel buildings (for issue approval)’ for investigation on the suitable estimation method of load-carrying capacity. The results show that, distortional buckling can occur for high-strength cold-formed thin-walled steel lipped channel columns subjected to axial compression with large width-thick ratio; By using the equivalent plate method to estimate the effective area of plate element with intermediate stiffeners, the related provisions in ‘Technical specification for low-rise cold-formed thin-walled steel buildings (for issue approval)’ can be reliably used to estimate the load-carrying capacity of axially-compressed high-strength cold-formed thin-walled steel lipped channel columns with nominal yield strength of 550MPa and thickness less than 2.00mm.