Seismic pushover analysis of unbraced adjustable pallet racks in the down-aisle direction. Need for multimode analysis

Abstract

Modal Pushover Analysis has been proposed to account for the higher modes contribution in seismic analysis of slender structures, such as unbraced racks in the down-aisle direction. In these structures, only single-mode pushover analyses have been used so far. This paper investigates a suite of 96 unbraced representative prototype racks, and six of them are selected to be analyzed through modal pushover analysis. Results show that global damage significantly exceeds that derived from considering the first mode alone, thus proving that higher modes contribution is relevant for racks with low mass participation in the first mode (<90 %).