An approach for the seismic design of steel storage pallet racks

Since some decades, one of the most significant uses of cold formed members is for steel storage racking structures. Despite this, suitable approaches have been recently proposed only for the monotonic design. In particular, specific tests are required to evaluate the behaviour of the key components of rack systems and, as a consequence, to determine main parameters governing member/connection response. By means of re-analysis of tests data, design phase of rack systems under static loading is carried out by a suitable use of the state-of-knowledge developed and codified for traditional cold-formed members. As to seismic design, no extensive research activities have been developed and the sole indications are provided in the U.S.A. Rack Manufacturing Specifications, while the Eurocode 8, (i.e., the European design provisions for the earthquake resistance of structures) doesn't refer to rack systems. This paper deals with a study, which is currently in progress at the - Politecnico di Milano (I), on the development of simplified rules for the design of steel storage pallet rack systems in seismic zones. A design approach, which has been developed in previous researches on traditional steel buildings, is herein briefly introduced to be suitably extended to rack systems. Moreover, the experimental activity of the study, which has been planned to investigate the behaviour of racks under seismic loading, is singled out and the very preliminary results of beam-end-connector tests under cyclic reversal loading are shortly presented. Finally, the numerical phase of the research is briefly described, which is aimed to calibrate the design approach on the basis of full scale tests on shaking table.