Optimum web stiffener for the buckling stability of web perforated cold-formed steel storage rack columns

Abstract

Storage rack structural systems have occupied a remarkable share of the global market due to the demanding logistics operations. Uprights are the primary compression member that controls the overall stability of the rack system. For a sustainable structural system, moving towards maximum material utilization, there is increasing research on the cross-section optimization of storage rack uprights, while maintaining the limit state stability at cross-section as well as member level. The current article presents the results from an ongoing experimental research work, addressing the effect of web stiffener in the local buckling of cold-formed steel (CFS) rack uprights in the presence of patterned web perforations throughout the length. Finite element numerical models of the simple rack and lipped rack sections are carefully validated using tested specimens, and an extensive parametric study which includes various web-to-flange width ratios and non-dimensional slenderness ratios is conducted to cover a wide range of web stiffener size, shape, and included angle. The columns are subjected to concentric compression load with fixed end supports. The objective of the study is to encourage practitioners to optimally design the web stiffener of CFS web perforated columns utilizing the local post-buckling reserve strength due to the presence of the web stiffeners. Further, the study examines the accuracy of the well-established DSM-based strength predictions for the wide range of local non-dimensional slenderness ratios, in the presence of web stiffener and web perforations, which allows simpler reiterative design procedures. © 2025 SSRC. All Rights Reserved.