Experimental and numerical investigation on cold-formed steel C-section flexural members

This paper presents an experimental and numerical investigation on the bending strength and behavior of cold-formed steel C-section flexural members with upright, inclined and complex edge stiffeners. A total of 24 specimens that divided into 12 tests including 6 pure bending tests and 6 non-pure bending tests have been conducted. Local buckling, distortional buckling and interaction between local and distortional buckling were observed in the tests. The experimental results show that the edge stiffener and buckling mode have great influence on member’s bending strength. Comparison of the bending strengths under the two bending states show that the bending strength under non-pure bending is higher than which under pure bending, but the increased magnitude is related to the buckling modes. Moment gradient effect has only a minor influence on local buckling, but has great influence on distortional buckling. The tests were simulated by finite element program of ANSYS and the simulated results show good agreement with the experimental results in terms of bending strength and buckling mode.