A shape memory alloy-based reusable hysteretic damper for seismic hazard mitigation

Abstract

This paper presents a special shape memory alloy-based hysteretic damper with distinctivefeatures such as tunable hysteretic behavior and ability to withstand several design levelearthquakes. Superelastic nitinol stranded wires are used for energy dissipation in thisdamping device, termed a reusable hysteretic damper (RHD). By adjusting its designparameters, the hysteretic behavior of the RHD can be modified to best fit the needs forpassive structural control applications. Adjustable design parameters of the RHD includethe inclination angle of the nitinol wires, pretension level, and friction effect.A simulation-based parametric study was carried out to examine the effects ofthese design parameters of the RHD on its energy dissipating performance. Theeffectiveness of the RHD in passive seismic response control of civil engineeringstructures is examined through a nonlinear dynamic analysis of a three-story steelframe building with and without an RHD. The simulation results suggest that itcan effectively reduce the structural response of building structures subjected tostrong earthquakes. With proper design, an RHD can be reused for several strongearthquakes without the need for repair, due to the high fatigue life of nitinol wires.