In-plane behavior of cold-formed thin-walled beam-columns with lipped channel section

• We conduct the experimental investigation on ultimate capacity for cold-formed, thin-walled beam-columns.
• The ANSYS model is developed and verified by test results.
• The elastic local buckling loads and second order effect are discussed in this paper.
• A comparison is made between test results and nominal strength obtained by AISI specifications.

This paper is mainly concerned with the in-plane behavior of cold-formed steel beam-column with lipped channel section. The tested members are classified into three series by loading types, including: axial compression and major axis bending (X), axial compression and minor axis bending (lips in tension, Y1), and axial compression and minor axis bending (lips in compression, Y2). A numerical model is developed and verified by the experimental results. The elastic local buckling loads and second-order effects are discussed based on results of test, numerical analysis and design methods. Comparing with test results in this paper, numerical analysis overestimates the elastic local buckling loads and the actual second-order effect is more severe than the prediction by current design methods. Finally, the comparison between test strength and predicted strength obtained by AISI specification indicates that the interaction equation can provide conservative strength prediction for beam-column.