Measurement of mechanical and electrical energy flows in the semiactive piezoelectric shunt damping system

The analysis of the mechanical and electric energy flows in the semiactive vibration control system, which is made of a piezoelectric actuator shunted by a negative capacitor, is presented. The vibration control system is designed to suppress the vibration transmission in a narrow frequency range. Using a proper adjustment of the electronic circuit elements, the transmissibility of vibrations has been suppressed by 35 dB at the frequency of 1.5 kHz. The results of our measurements indicate that the average apparent electrical power in the electric part of the vibration control device is about 100 times larger than the mechanical power, which is supplied to the system from the source of vibrations. The rules for designing the highly efficient and low-power electronic parts of semiactive vibration control systems are discussed.