DYNAMIC CHARACTERIZATION OF HAND-LOADED STEEL STORAGE RACKS

Hand-loaded shelving rack (SR) is a particular rack typology that represents a widespread solu-tion for private applications, superstores open to the public and laboratories. Due to their lim-ited weight, the cost of these structures is remarkably low, but the possible collapse could lead to a loss of products and goods, injuries and suspension of the activity of the stores. For these reasons researchers put more and more attention on the peculiarities of their complex struc-tural behaviour. Despite the recent improvement of the European codes for static and seismic design, more specific suggestions are needed and some important problems remain unsolved. The paper deals with an experimental and numerical dynamic characterization of two very common shelving racks having the same geometric layout but differ in the cross-section of the structural elements. It can be remarked that the behavior of these structures is quite par-ticular and complex because of the presence of mono-symmetric cross-section uprights, the presence of perforations, the nonlinear behavior of the beam-to-column joints and the behav-ior of the base-plate connections which have strength and stiffness dependent on the vertical load applied to the rack. After a summary of the experimental tests on both components and frames, structural re-sponses have been simulated by means of an academic finite element software (called Śiva) able to capture key features of the nonlinear response of SR with mono-symmetric cross-section member. The results are presented and discussed, showing the good agreement with tests and software, highlighting the importance of the use of an advanced beam element for the analysis of these structures