冷弯薄壁型钢四肢组合轴压构件承载力试验研究

Experimental study on bearing capacity of cold-formed thin-wall steel quadruple-limbs built-up components under axial loading

对12根冷弯薄壁型钢四肢组合箱形截面柱进行了轴压试验,研究该类试件的极限受压承载力和破坏形态。试件共有3种截面类型,均由2个C形构件和2个U形构件通过自攻自钻螺钉组合而成,试件长度均为3.0m。试验结果表明：该类试件均发生局部屈曲破坏,破坏具有突然性;试件屈曲破坏前表面有明显的波纹变形,试件整体协同工作性能较好,没有发生钉子剥落、被剪断情况。在此基础上对试件进行有限元分析,数值分析结果与试验结果吻合较好,同时依据《冷弯薄壁型钢结构技术规范》（GB 50018—2002）计算组合构件中的各单根构件受压承载力,并将结果叠加,发现试验结果约为该叠加值的2-5倍。

The axial loading experiments on 12 cold-formed thin-wall steel quadruple-limb built-up box columns were carried out. The ultimate bearing capacity and failure modes of the specimens were investigated. The specimens had a total of 3section types with length of 3. 0m,all of which were composed of two C-shaped and two U-shaped components,and assembled through self-drilling screws. Experimental results show that all specimens are prone to locally buckle and damage suddenly. There is obvious corrugation deformation before damage on specimens. The collaborative performance of a whole specimen is good,and no nails are peeled and cut. On the basis of experiments,the finite element analysis was taken. The analysis results are in good agreement with the experimental results. Meanwhile the bearing capacity of the single component was calculated according to Technical code of coldformed thin-wall steel structures（ GB 50018—2002）,and added together. The experiment value was about 2 - 5 times as large as added value.