Innovative Superelastic Isolation Device

The objective of the present work is to propose a new seismic isolation device based on superelastic material components manufactured using shape memory alloys. Seismic isolation is one of the most effective options for the passive protection of structures. Shape memory alloys (SMAs) are characterized by unique mechanical properties due to a solid-solid transformation. An isolation bearing system based on a SMA superelastic effect is intended to provide nonlinear flag-shaped lateral displacement-shear force hysteresis, additional damping, and recentering properties to reduce or eliminate the residual deformations. The device concept is based on two separate systems, one to transmit the vertical load and another to act as a lateral restrainer. This article presents in detail the mechanical components of the innovative device focusing on its main properties. The system theoretical response is computed, resulting very attractive from the earthquake engineering point of view, because of its capability in reaching the design goals, i.e., modification of the structural response, ability to undergo large displacement demand without loss of strength, energy dissipation, and recentering after the seismic event.