Vibration Isolation of Structure Connected with SMA Helical Springs

In the present paper, a new kind of isolation system — SMA helical spring isolation system is proposed to reduce structural horizontal vibration. Instead of SMA wire, SMA helical spring is adopted to make up the isolation system. In terms of cyclic tensile experiments, the hysteresis model of the SMA helical springs is built up for numerical simulations utilizing linear and exponential functions to fit the experimental data. Furthermore, the basic principles are provided so that the hysteresis model given is applicable for the structural response under the earthquake wave. With respect to EI Centro earthquake wave record, a sequence of shaking table experiments of the steel frame equipped with SMA helical springs are carried out, and numerical simulations are also accomplished for comparison. Numerical results show that the proposed isolation system has excellent isolation efficiency and the ability of full recentering. Also they have a good agreement with that of the experimental simulations.