Design and experimental investigation of a superelastic SMA damper

Based on shape memory alloy (SMA) superelastic properties, a new SMA damper is designed and manufactured. Experiments were taken to investigate the influence of frequency and displacement amplitude on the damperʹs mechanical behavior. The results show that, in the range of experimental frequencies, the frequencies have slight effects on SMA damperʹs mechanical parameters such as the stiffness and dissipated energy; displacement amplitude is the major factor that affects SMA damperʹs mechanical behavior, that is, under small displacement, the damperʹs stiffness does not change, and dissipated energy increases linearly with displacement. On the other hand, under large displacement, its secant stiffness decreases; however, its dissipated energy increases greatly. It can be concluded that the SMA damper is a displacement-correlated and variable-stiffness damper.