Effects of steel bolts on retrofitting the buckling performance of storage rack system uprights

Storage rack systems, essential for product storage, encounter design challenges, particularly for uprights under axial loading. Despite being produced from thin-walled steel sheets, these systems are required to support excessive loads. Extensive research has focused on maximizing the load-bearing capacity of rack uprights in recent years. This study aims to enhance the axial load capacity of upright profiles through a retrofitting method of installing steel bolts and spacers. Experimental, numerical, and analytical evaluations were conducted to assess the effectiveness of bolt installation in enhancing axial strength of the uprights. Bolt installation altered buckling modes, suppressing distortional buckling. Results consistently showed an increase in axial load capacity with bolt installation, particularly notable in taller uprights. Comparison of experimental, numerical, and analytical results revealed good alignment, highlighting the positive impact of bolt installation on structural stability. Numerical analysis slightly underestimated experimental outcomes, especially for longer lengths, while the analytical approach showed a combination of overestimation and underestimation, with significant overestimation for longer lengths. The study concludes that bolt installation effectively increases the axial load capacity, especially for taller uprights. These findings offer remarkable insights on the positive effect of bolt installation for optimizing storage rack systems by enhancing structural stability and eliminating distortional buckling.