Experimental tests on beam-end connectors of cold-formed steel storage pallet racks

The key role of beam-column joints in the seismic response of moment resisting frames (MRF) has been fully recognized. In the performance-based seismic design of steel storage pallet racks, many researches have highlighted the need to take into account the inelastic response of beam-column joints. Pallet racks are characterized by boltless beam-column connections and the extensive use of thin-walled cold-formed steel members. Due to the great number of beam-end connector types and member geometries, specific tests are required to evaluate the structural behavior of these structures. In particular, their seismic analysis requires a thorough modeling of the behavior of beam-column joints, which has been investigated by the authors through experimental tests under monotonic and cyclic loads. Tested connectors have exhibited different values of the bending stiffness and the ultimate bending moment, depending on structural details of each joint’s type, like the number of tabs. Cyclic tests have shown a pinching in the hysteresis curve, underlining that the cyclic response of tested joints is significantly different from joints of traditional steel framed buildings. Experimental results confirmed the importance of cyclic tests on beam-end connectors to correctly identify their moment-rotation curve, which is required to perform reliable seismic analyses of steel pallet racks.