Measured performance of a semi-active tuned mass damper with acceleration feedback

Semi-active tuned mass dampers (STMDs) with magnetorheological (MR) dampers are becoming promising alternative to passive tuned mass dampers (TMDs) and active tuned mass dampers (ATMDs). In this paper, a new control algorithm for STMDs with acceleration feedback is experimentally evaluated in a laboratory wind tower - nacelle model equipped with a prototype STMD. The control algorithm adopts an existing acceleration feedback control approach which was originally proposed for ATMDs. The STMD consists of a mass, passive springs and an MR damper. The fail-safe operation of the STMD is reported due to both an internal friction of the STMD and a residual force of the MR damper at its off-state. The paper compares the simulated performance of the STMD with the measured performance of the fail-safe STMD under harmonic force excitation and discusses the major deteriorating factors that limit the measured performance. Despite the limitations, the paper reports that at low excitation the fail-safe STMD acts similarly to the TMD with same mass, while already at moderate excitation its performance is almost equally good as that of the TMD with two times larger mass.