Evaluation of the interaction between distortional–global buckling in perforated cold-formed steel rack sections

Abstract

Storage systems are typically designed using cold-formed profiles, with the columns of the system consisting of rack-type sections perforated along their entire length. These columns are subjected to compression, and their failure can be caused by local, distortional, or global instabilities, which can act individually or in combination, resulting in local–global (L–G), local–distortional (L–D), distortional–global (D–G), and local–distortional–global (L–G–D) interactions. However, the interactions with distortional buckling are not yet fully understood, particularly in the case of rack sections with perforations. Unlike cold-formed profiles without holes, which are covered by standards and can be calculated by analytical methods, rack sections with perforations always require testing, and no analytical procedure is recommended. Therefore, an extensive parametric study developed through numerical simulations via ABAQUS software was performed to evaluate the interactions between D–G-type buckling in perforated rack profile columns. A total of 3055 post-buckling analyses were developed with previously selected columns via buckling analysis, where D–G interactions were verified. Finally, the direct strength method (DSM) was used, and its results were compared with those obtained by non-linear analysis. The DSM presented significant variability in the results, and a new DSM-based equation was proposed for each boundary condition.