Performance of baseplate connections in steel storage rack systems: an experimental and theoretical study

Driven by the rapid growth of the storage industry, cold-formed steel storage racks have become a widely adopted structural solution for maximizing capacity. Due to the slenderness of the down-aisle direction frame, even small variations in baseplate stiffness can significantly impact the global load-carrying capacity. However, main rack design specification do not provide enough guidelines to assess influence of semi-rigid steel storage rack baseplate to upright connection, and several details of standardized test specifications remain ambiguous, potentially leading to inaccurate design parameters. This paper proposes an experimental and theoretical investigation into the mechanical behavior of baseplate to upright connections in steel storage rack frames. Twenty-one specimens were tested under combined bending and axial compression using an alternative test method. Two anchorage configurations were evaluated: one based on a typical manufacturer’s design and another solution proposed in this study. Based on the test results, the analysis focuses on (i) the reliability of current rack design standards in determining ultimate limit state stiffness and strength, (ii) the serviceability rotation limit, and (iii) analytical methods for estimating baseplate stiffness. The findings highlight inconsistencies in standardized specifications and provide the basis for an improved baseplate design solution. The observed semi-rigid moment–rotation response reveals the effects of compression force, anchorage configuration, and upright stability on connection performance. Comparative analysis shows that the proposed baseplate arrangement significantly improves ultimate stiffness design, mitigates torsional effects, and offers more reliable structural behavior under design loads.