LAUSR

Storage racks are nonstructural components mainly designed to support the vertical load of goods. During strong external loads such as an earthquake, which acts in the lateral direction of the racks, stored goods become structurally vulnerable. To identify and reinforce the vulnerable parts of storage racks and improve their seismic performance, we developed a viscoelastic damper system with a capacity designed for storage racks. First, we performed an experiment to analyze the behavioral characteristics of a pallet rack — a representative storage rack used for large goods — under vibration. Based on the results of the experiment, we chose the members of storage racks that were vulnerable to vibration. For the proper seismic reinforcement of vulnerable members, we developed a viscoelastic damping system for storage racks by calculating the structural shear force on each floor of the rack and the capacity of the damper to distribute the shear force. First, three viscoelastic dampers of different capacities were fabricated using a viscoelastic material and subjected to cyclic loading tests to evaluate their mechanical performance. We determined the position on which the damper should be placed to improve the rack’s seismic performance by considering the shear force on each floor of the storage rack and its operational characteristics. Finally, we conducted a shaking table test to verify the new viscoelastic damper system. The system improves the seismic performance of storage racks by controlling their elastic and permanent deformations.