Experimental and Numerical Investigation of Corroded Cold-Formed Steel Channel Section Columns Subjected to In-Plane Compression and Bending

This paper investigates the effect of corrosion on bearing capacity of corroded cold-formed steel (CFS) channel section columns subjected to in-plane compression and bending. Herein, 14 CFS columns with different column lengths and corrosion degrees were investigated. The mass loss rate, surface morphology, and initial geometric imperfections of corroded CFS columns were measured. The eccentric compression test of corroded CFS columns that were accelerated corrosion by the outdoor periodic spray test were carried out. The relationships among the failure mode, load–strain curves and load–axial displacement curves, and mass loss rate were analyzed, and then the deterioration laws of bearing performance of corroded CFS channel section columns were discussed. The non-linear finite element model for corroded CFS columns considering surface morphology was then developed by using Geomagic Studio and ABAQUS. The results indicated that the local and overall initial geometric imperfections of corroded specimens were greater than those of non-corroded specimens. With increasing mass loss rate, the distortional buckling deformation of corroded CFS columns occurred in advance and the failure locations were diversified. Corrosion exhibited a greater impact on the buckling critical load than on the ultimate load and post-buckling strength. The failure positions of corroded CFS channel section columns subjected to in-plane compression and bending were found to be mainly related to the areas with severe corrosion of the flange.