冷弯薄壁型钢组合墙体墙架柱的轴压性能试验研究

Experimental study on the axial behavior of cold-formed thin-wall steel framing wall studs

对冷弯薄壁型钢组合墙体墙架柱的轴压性能进行试验研究,分析是否覆墙面板、墙面板材料、自攻螺钉间距以及墙架柱间距等因素对墙架柱在竖向荷载作用下的稳定承载力的影响。6块足尺组合墙体试件的试验结果表明:墙架柱覆墙面板后,竖向荷载下的稳定承载力提高明显;纤维增强硅酸钙防火板(CSB板)约束的墙架柱较单面定向刨花板(OSB板)约束的墙架柱稳定承载力提高18.8%;墙面板为OSB板采用常规螺钉间距150mm和300mm时,螺钉间距改变对墙架柱稳定承载力影响微小,但当墙面板为CSB板时,螺钉间距由300mm加密至150mm,稳定承载力反而减小;墙架柱间距增大时,其稳定承载力略有降低。通过研究GB 50018—2002《冷弯薄壁型钢结构技术规范》与试验结果的对比,提出各组合墙体墙架柱计算长度系数的建议取值,同时提出通过对规范公式添加修正系数来考虑各种因素对墙架柱稳定承载力影响的设计方法。

A full-scale experimental study on the axial behavior of cold-formed thin-wall steel framing wall studs is carried out. The influence of the parameters, including whether the studs are sheathed or not, the stuff of sheathings, the screw spacing and the stud spacing, on the bearing capacity of the studs under vertical compression, is analyzed. The test results of the six wall panels show that, the load carrying capacity of a stud increases significantly when it is covered by sheathings; the ultimate load of the stud sheathed with fiber reinforced Calcium Silicate Board （CSB） is about 18.8 percent higher than that sheathed with Orient Strand Board（OSB） ; when the wall frames are sheathed with OSB or plasterboard, there is little effect on the bearing capacity by changing the screw spacing, however, the bearing capacity will fall when the frames are sheathed with CSB as well as the screw spacing is decreased from 300mm to 150mm; when the stud spacing increases, the bearing capacity of stud decreases slightly. By studying the comparison between the results of the test and those from the GB 50018--2002 Technical code of cold-formed thin-wall steel structures, the effective length factors of the studs are suggested. In order to consider the influence of different parameters on the bearing capacity of a stud, a method by adding compensation factors to the equation in the code is suggested.