This paper presents two parallel experimental studies on time-varying semi-active piezoelectric and electromagnetic units for the control of low-frequency flexural vibrations of distributed structures excited by stationary stochastic disturbances. The studies show that the resulting sweeping vibration absorbers effectively reduce the vibration of the hosting structures over the frequency range of the sweeps without the need of a precise tuning, which would require an accurate system identification of the flexural response of the structures. This result suggests that the two semi-active control systems can effectively work under changes of the physical properties of the hosting structures due to operation conditions.
