Experimental testing campaign and numerical modelling of an innovative base-plate connection for pallet racking systems

The problem of the high fragility of upright frames of pallet racking systems against lateral forces raises an important question for researchers. This lack of seismic performance can be attributed to a small degree of internal overdetermination of the system, as is also acknowledged by the European Standard for adjustable pallet racking structures (EN16681), which only takes into account the low-dissipative behaviour for these structures. This paper presents an innovative base-plate connection that can provide the upright frames of pallet racking systems with a certain degree of global ductility, thus improving the seismic attitude of these structures when seismically stimulated along the cross-aisle direction. A design procedure for the specimens to be tested is proposed, which aims at guiding the system design toward localizing yielding strains in the plates of the base connections, as the principles of the capacity design posit. The proposed base-plate connection is tested under monotonic and cyclic loads to better understand its properties and, by inference, its dynamic characterization, which could be utilized in a lighter numerical model in order to study overall performance improvement. Additionally, a numerical model of the specimen, as tested in the Laboratory of Steel Structures at the National Technical University of Athens (Greece), which has been calibrated and validated in accordance with experimental tests results, is presented.