Numerical analyses of a base connection for a thin-walled cold-formed profile column

Thin-walled cold-formed steel structures tend to gain more attention in the civil engineering field. Ground-floor dwellings, as well as factory warehouses represent the most frequent use of these structural systems. However, due to the inherent flexibility of thin-walled cold-formed steel elements, the designer has to take into consideration the possibility of large deformations occurrence, especially in the case of structures with large openings. Such deformations may lead to significant stresses at the level of the connection joints between elements or between elements and the foundation block. The paper presents a comparative numerical analysis based on the finite element method to assess the efficiency of a connection joint between the columns of a portal frame and the foundation block. The linear and nonlinear analyses were carried out by means of Robot Structural Analysis and Ansys. The column is made of two thin-walled cold-formed C shape profiles positioned back-to-back. The efficiency was assessed both from a stress-state point of view in the column and in the connection parts, as well as from the point of view of the manufacturing process and implementation. Significant differences were observed regarding the stress distribution in the nonlinear analysis. (paper)