Design of channel columns with inclined edge stiffeners

Abstract

Design and numerical investigations of cold-formed steel channel columns with inclined edge stiffeners are presented in this paper. The edge stiffeners of the channel sections consisted of simple lips that inclined at different angles both outwards and inwards. Finite el ement analysis was used in the numerical investigation. A non-linear finite element model was developed and verified against fixed-ended column tests. Geometric and material non-linearities were included in the finite element model. It is shown that the finite element model closely predicted the experimental ultimate loads of the cold-formed steel channel columns with inclined edge stiffeners. Hence, the model was used for a parametric study of cross-section geometries. The column strengths predicted by the finite element analysis were compared with the design column strengths calculated using the American and Australian/New Zealand specifications for cold-formed steel structures. The design rules in the American and Australian/New Zealand specifications for designing an edge-stiffened element are mainly based on tests of channels with simple edge stiffeners perpendicular to the flanges. However, these specifications allow the design of inclined edge stiffeners that are purely intuitive. It is shown that the design column strengths calculated from the specifications are generally conservative for cold-formed steel channel columns with inclined edge stiffeners.