LOKIBASE: The Device for Seismic Isolation of Pallet Racking Systems—Optimization Analysis

LOKIBASE is a non-linear isolator/dissipator device to protect pallet racking systems against the earthquake. LOKIBASE consists of the following main components: (1) two slider devices on which a rubber membrane is set up (LOKI devices). LOKI devices are linear displacement dependent ones; (2) a cylindrical beam damper (“CANDLE” device). The “CANDLE” device is a non-linear displacement dependent one; (3) two anti-lifting devices (“UP-LIFT” devices); (4) a fuse plug (see www.lokibasedevice.com). The main work which is the purpose of the paper, is the optimization of the behavior of an isolator/dissipator device to mitigate the seismic action on special structures, where the stiffness values are very different in the main cross-aisle and down-aisle directions. Under seismic action, in these structures it is very important to reduce the value of the forces at the Limit state for the safeguard of human life (SLV) in the down-aisle direction as much as possible and simultaneously to use the highest damping value allowed by the building rules to reduce the LOKIBASE displacement at the Limit state for collapse prevention (SLC) in the cross-aisle direction. The goal was achieved through a cylindrical device made of stainless steel (AISI304) with an optimized shape, under large displacement during seismic action.