PSI - Issue 78

Alessandro Mei et al. / Procedia Structural Integrity 78 (2026) 120–127

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Fig. 1. Cross-sections of investigated joints

2.2. Strengthening types Different strengthening types have been tested aiming at the following scopes: increase the stiffness of the connection to decrease sway sensitivity in down-aisle direction, increase the collapse moment, and enhance the capacity of the joint to dissipate energy under cyclic loads. Moreover, they should be simple, easy to install and economical. The designed and tested strengthening types (Fig. 2) are: • r01: M12 reinforcing bolt between the joint plate and the upright, • r02: 45° bracket installed below the beam (no space available above due to stored goods), fixed by bolt, • r03: 90° brackets placed above and below the beam, fixed using M6 self-drilling screws, • r04: 90° brackets placed above and below the beam, fixed using rivets, • r05: U-shaped reinforcing plate designed to clamp around both the beam and the upright, • r06: 90° brackets placed above and below the beam, fixed using a M12 bolt. . 2.3. Testing protocol and instrumentation Monotonic and cyclic tests were carried out on a testing bench (Fig. 3) designed according to the EN 15512 CEN European Committee for Standardization (2009). Experimental tests concerned full-scale specimens of beam-upright joints. Each tested specimen consisted of a 750 mm long upright and a 650 mm long pallet beam. The application point of the vertical load P was at a distance d of 400 mm from the upright edge. In monotonic tests the load P was applied until the failure of the specimen, while in cyclic tests the displacement history according to ANSI - RMI (2023) was employed.