Influence of Uniformly Distributed Corrosion on the Compressive Capacity of Selected Thin-Walled Metal Columns

Estimation of the compressive capacity of selected types of cold-formed steel columns subjected to surface corrosion is the objective of this article. Symmetric “C” section and bisymmetric “double C” section, composed of two sections connected by webs are taken into account to simulate different degrees and patterns of corrosion that appears uniformly along the inner and the outer column surfaces. Reduction of the cross-sectional area that appears due to corrosion, results in decreasing of the cross-sectional moment of inertia, variation of the principal central axes position and slope as well as in appearance of eccentricity of loading and in appearance of an additional bending moments. Reduction of the column compressive strength, changing of the buckling mode, e.g. from the flexural mode into warping, considerable increase of the column displacement are observed results of the surface corrosion growth. The theory of thin-walled bars is applied for the analysis.