An experimental investigation of stiffened cold-formed C-channels in pure bending and primarily shear conditions

• Installation of top flange cover plates will reduce the non-dimensional slenderness.
• Interaction equation between M and V as suggested by AISI is conservative.
• The DSM and equation between M and V established good agreement.

This paper is based on an investigation into the performance of cold-formed C-channels stiffened with cover plates and subjected to pure bending and primarily shear condition tests. Cover plates with three different thicknesses (1.6, 2 and 2.4 mm) were installed at top flanges only as it would be the predicted location for local and distortional buckling. The local and distortional buckling capacities were evaluated via Direct Strength Method, DSM, in accordance with AISI 2007. The accuracy of the interaction equation between the required flexural strength, M, and the required shear strength, V, prescribed by AISI 2007 was also investigated in this paper. A nonlinear finite element model was developed and verified against the test results in terms of maximum strength and buckling failure modes. The results explicitly showed that by attaching the cover plate on top flanges, the non-dimensional slenderness decreased resulted in improved buckling capacities, where the nominal flexural moment of sections, Mn, were close to the plastic moment, MP. Besides, it was concluded that the interaction equation between M and V predicted by AISI was conservative for sections with small non-dimensional slenderness values.