Influence of mechanical and geometric uncertainty on rack connection structural response

Steel storage pallet racks are used worldwide for storage of palletized goods and are popular for their ease of construction, customization, and economy. Failure of these racks can result in significant property loss and economic disruption. Ultimately, the structural behaviour of these systems can be characterized as braced systems, in the cross-aisle direction, and un-braced moment resisting frame systems, in down-aisle direction. The structural capacity of these moment resisting frames depends on the performance of beam-to-column connections. Rack connections are typically formed by beams welded to connectors with tabs and columns with perforated cross-sections to accept these tabs joining beams and columns without bolts. This paper aims to evaluate the influence on the structural response of rack connection due to the structural details, and randomness in the geometrical features and mechanical properties of connection members (beam, weld, connector and column). To explore the impact of variability in design parameters on the initial flexural stiffness and ultimate flexural capacity of rack connections, a Monte Carlo simulation was conducted, using the Component Method to model the connection. Variability in member geometrical features was determined from current design specifications, while variability in steel mechanical propertieswas determined via experimental tests. The results indicate that system effects reduce flexural stiffness and the variability in the response of individual components does not propagate to the overall flexural capacity. Ultimately, the work motivates accurate and thorough reporting of geometric and structural uncertainty to accurately assess rack connection performance.