FEM analysis of the buckling behavior of thin-walled CFS columns. Part I-Channel (C) and Double Channel (I) cross-sections

Abstract

One of the main advantages of thin-walled CFS profiles is the "freedom" the designer has to conceive a cross-section shape tailored for the structural application. Consequently, different cross-sections shapes have been developed and may be found in the market. Furthermore, the combination of thin-walled CFS profiles, in the form of built-up cross-section members, further increases the range of available options. On the other hand, this diversity of solutions brings a challenge to the designer, as for some uncommon cross-section shapes, the mechanical behavior is not entirely known and therefore not covered in the design codes. Hence, in this paper, the buckling behavior of thin-walled CFS columns is investigated by means of FEM. The numerical models were developed and calibrated using experimental results on lipped channels and open built-up I cross-sections. Upon validation, a parametric analysis is performed, to further assess the influence of different parameters, such as steel thickness, material grade, cross-section dimensions, boundary conditions and connection spacing, in the case of the built-up cross-section.