This paper presents initial experimental results on the practical implementation of time-varying semi-active
electromechanical units to control the low frequency vibrations of flexible structures excited by stationary
stochastic disturbances. Two types of control units are considered: first, electromagnetic and second,
piezoelectric transducers. The two electromechanical vibration absorbers are connected to time-varying
electrical shunt circuits. The study shows that the proposed semi-active sweeping electromechanical
vibration absorbers effectively reduce the vibration level of the structures over the range of frequency
considered and without the need of a precise tuning, which would require an accurate system identification.
This is a rather interesting result since it suggests that the two semi-active control systems can effectively
work under changes of the physical properties of the host structure.
