An advanced design procedure for the safe use of steel storage pallet racks in seismic zones

In this paper, the well-established non-linear time-history (NLTH) method of analysis is combined with the low-cycle fatigue (LCF) damage approach in order to (1) investigate the damage distribution, (2) assess the residual fatigue life and (3) estimate the effective load-carrying capacity after an earthquake. In particular, key open problems related to the seismic design of racks are identified and the NLTH-LCF procedure is introduced and discussed. Finally, attention is focused on a practical case study related to a medium-rise doubly-entry pallet rack. Reference is made to two recent Italian earthquakes and two models have been adopted to reproduce the cyclic joint behavior of beam-to-column joints allowing for a direct appraisal of its influence on the overall rack response.