Dynamic identification of selective steel storage pallet rack

Steel storage pallet racks are formed by cold formed steel members and are used worldwide for storage of palletized goods. The main racking system is called the “selective steel storage pallet rack”. Selective racks behave like bracing systems in the cross-aisle direction, with columns connected by diagonal braces. In the down-aisle direction, racks behave like moment resisting frames, whose stability and dynamic response is mainly affected by the beam-to-column connections and the column base plate connections. The paper presents a study on the dynamic cross-aisle and down-aisle behavior of selective steel storage pallet racks. The dynamic response of a three bays full scale rack system under three different load levels is investigated through pullback tests. In addition, the effect of the impact due to a forklift truck is simulated and the propagation in accelerations and strains between consecutive upright frames is analyzed. The objectives of the ongoing research activity are the evaluation of the natural frequency and damping coefficient of the system. Moreover, recommendations in type, number, and position of monitoring structural devices alerting the impact of forklifts and assessing damage on structural members are provided.