Experimental and Theoretical Investigations of Pallet Racks Connections

Abstract

Steel storage pallet racks are three-dimensional framed structures, similar to multi-storey building structures. They are widely used for the storage of different types of materials. To provide the easy accessibility to stored products, pallet racks are not braced in down-aisle direction. The only source of the stiffness required for down-aisle stability is the stiffness of the connections between columns and beams, and the stiffness of the column bases. Connections between columns and beams are realized by means of different types of mechanical devices (tabs, hooks etc) without the need of using bolts and welds. Such joints have non-linear φ − M characteristic. Most of the recent design codes and papers recommend experimental tests of beam-to-column connections to obtain semi-rigid joint characteristics that can be applied in the global analysis. The aim of this paper is to present application of the component method to assess main joint properties, i.e. the moment resistance and initial stiffness of storage rack joints. Results obtained using developed model are compared with the test results.

Structural Performance of Boltless Beam End Connectors

“…The leg of the angle with tabs is in contact with column web after assembly, while there is a 2 mm gap between the second legs, perpendicular to the column web. Figure 4 is modified from Figure 2 of [2]. However, in this study, the tabs of the BEC were reversely engaged into the column perforations.…”

“…These lightweight structures can carry live loads much heavier than their self-weight [2]. The most commonly used type of storage racks is 'steel pallet racks (SPRs)'.…”

“…The other unique feature of SPRs are the unique boltless connections used as BCCs in these structures [5]. These boltless connections are considered semi-rigid connections in nature [2]. By contrast to the common structural steel connections where bolts or welds are used for joining the beams and columns, these structures utilized a connection device namely the 'beam end connector' (BEC), which is welded at the end of pallet beam and its stiffness supports the bending capacity of the pallet beam.…”

Steel Rack Connections: Identification of Most Influential Factors and a Comparison of Stiffness Design Methods

“…The effective use of SPRs demands flexibility in the material constituting these racks. Thus, cold formed steel is preferred for the manufacturing of these peculiar structures in order to permit the handy adjustment and reassembling of rack elements upon requirement and due to its good strength-to-weight ratio [ 1 ]. However, AS4084 [ 2 ] permits the use of hot rolled steel for manufacturing when the rack has to support heavy loads.…”

“…The BCCs in building structures are traditionally considered to fulfill the conditions of either a hinge or a fixed-end restraint. The SPR BCCs are treated as semi-rigid connections and the structural analysis is carried out by adopting a semi-continuous sway frame model [ 1 ].…”