The objective of this paper is to investigate the buckling behavior and to present the design method of the ultimate strength in the basic effective width method (EWM) for cold-formed steel (CFS) lipped channel stud columns with holes in the web. 28 column tests were conducted under axial compression on the CFS lipped channel stud columns with circular and rectangular holes in different dimensions of cross sections and holes. The tested stud columns included 4 members without holes, 12 members with circular holes, and 12 members with rectangular holes. The test results showed that the stud columns with holes were governed by local buckling or the interaction of local buckling and distortional buckling. Compared with the stud columns without holes, the small hole had a slight influence on the ultimate strength of the tested specimens, and the large hole had a great effect on the ultimate strength of the tested specimens. The load capacities of the specimens decreased with the increase of the dimension of holes. Then, the finite element analysis was carried out to simulate the tested stud columns. The finite element analysis results showed good agreement with the experimental results about buckling modes and ultimate strengths, which indicated that it is feasible to analyze this kind of stud columns with holes by using the finite element method (FEM). Finally, the proposed effective width method was used to predict the ultimate strengths of stud columns with holes based on the proposed buckling coefficient formulas of the plate with holes. The comparison between calculated results and test and finite element results indicated that the proposed EWM is feasible and accurate to predict the ultimate strength of the CFS lipped channel stud columns with holes in the web.

中文翻译：

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带孔冷弯型钢带边槽钢立柱的试验研究及有效宽度法

本文的目的是研究屈曲行为，并提出基本有效宽度法 (EWM) 的极限强度设计方法，用于冷弯型钢 (CFS) 唇形槽钢柱在腹板上有孔。28 根柱子在轴向压缩下进行了 CFS 唇形槽柱柱，这些柱子具有不同尺寸的横截面和孔洞的圆形和矩形孔。被测螺柱柱包括4个无孔构件、12个圆形孔构件和12个矩形孔构件。试验结果表明，带孔螺柱柱受局部屈曲或局部屈曲和扭曲屈曲的相互作用控制。与无孔螺柱柱相比，小孔对试件的极限强度影响较小，且大孔对试件的极限强度影响较大。试样的承载能力随着孔尺寸的增加而降低。然后，进行有限元分析以模拟测试的螺柱柱。有限元分析结果与屈曲模态和极限强度的试验结果吻合较好，表明采用有限元法（FEM）对此类带孔螺柱柱进行分析是可行的。最后，基于所提出的带孔板屈曲系数公式，采用所提出的有效宽度法预测带孔螺柱柱的极限强度。