Behavior of Cold-Formed Steel Plain Angle Columns

The main objective of this paper is to provide an efficient and accurate finite element model to understand the behavior of cold-formed steel plain angle columns. The effects of initial local and overall geometric imperfections have been taken into consideration in the analysis. The material nonlinearities of flat and corner portions of the angle sections were incorporated in the model. Failure loads and buckling modes as well as load-shortening curves of plain angle columns were investigated in this study. Furthermore, the residual stresses of a column test specimen were measured and plotted. The effect of residual stresses on the buckling behavior was studied using the finite element model. The nonlinear finite element model was verified against experimental results. The finite element analysis was performed on plain angles compressed between fixed ends over different column lengths, and column curves were obtained. An extensive parametric study was carried out using the finite element model to study the effects of cross-section geometries on the strength and behavior of angle columns. The column strengths predicted from the finite element model were compared with the design strengths calculated using the American Specification and Australian/New Zealand Standard for cold-formed steel structures. In addition, the results obtained from the finite element model were also compared with the design strengths obtained from the design rules proposed by other researchers.