Finite element analysis of pinned cold-formed plain channel columns of different width-to-thickness ratios is presented in this paper. The study is focused not only on axially loaded columns, but also on eccentrically loaded columns. The general purpose finite element software ABAQUS 6.12 was used, and the force controlled loading was adopted. Geometric and material nonlinearities were incorporated in the finite element model. The ultimate loads are compared with the direct strength method (DSM) for axially loaded columns. Also, a parametric study is done by varying the length of the column and width of the unstiffened element. It is observed that the results correlate better with the DSM values for columns having unstiffened elements of lower ratios. The change in ultimate load is studied only in ABAQUS, as the position of load moves towards the free edge and the supported edge of the unstiffened element. A parametric study is done by varying the nonuniform compression factor for the columns. It is observed that the ultimate load increases as the position of load moves towards the supported edge and it is influenced by the ratio of the unstiffened element. 1. Introduction There are two main categories of steel structural members, namely, hot-rolled and cold-formed sections. Hot-rolled sections are quite familiar. Cold-formed steel sections have been used in car bodies, railway coaches, equipment, transmission towers, and so forth. Their application as structural members is the prime interest of ongoing research. Cold-formed members are generally known for their thin elements, buckling behaviour, and postbuckling strength. They have high strength-to-weight ratio and a thickness as small as 0.5？mm can be achieved. In the cold-formed family, many configurations such as angle, channel, I, Z, sigma, T, and tubes can be produced. Some of them are entirely composed of stiffened elements or unstiffened elements or a combination of both. Owing to the existence of such elements, each section behaves in its own way. This paper has focused on the behaviour of plain channel sections. Plain channel members are generally used as wall studs, rafters, truss members, and floor joists. In North America, channels have been categorised as S members which are lipped channels, most often used for wall studs, floor joists, and ceiling or roof rafters, T members which are unlipped channels, used for top and bottom plates (tracks) in walls and rim joists in floor systems, and U members which are again unlipped channels but have a smaller depth than tracks and are used to brace
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