Monotonic and Cyclic Behaviour of Base-Plate Joints of Steel Storage Racks: An Experimental Study

Industrial steel storage pallet racks are commonly used in the logistic field for storing goods and products. Several typical features characterize these structures, i.e. the use of cold-formed mono-symmetric perforated columns (uprights), the presence of beam-to-column and base-plate non-linear semi-rigid joints. In addition, bracing systems are provided only in the transversal direction (cross-aisle) while in the longitudinal direction (down-aisle) the structural global response is driven only by the joints performance. Therefore, being the baseplate and beam-to-column joints the sources of racks ductility, their key role becomes even more important in case of seismic actions. The design of racks is usually based on the ‘design by testing’ approach, which requires the complete characterization of racks main components and subassemblies. In case of seismic design, tests must be performed in the cyclic regime. In this context, experimental studies were performed in the past for the cyclic characterization of beam-to-column joints. On the contrary, although the key role of base-plate joints is well recognized, the available experimental studies regarding this component are still quite limited. As a contribution to this topic, an experimental study focused on the characterization of a commercial pallet rack base-plate joint was performed at the Università di Trento. The study comprised both monotonic and cyclic tests. The present paper describes and discusses the main features and the main results of the experimental programme.