Experimental determination of dissipative properties of electro viscoelastic systems with external electric circuits

Piezoelectric elements connected to shunt circuits and bonded to a mechanical structure form a dissipation device that can be designed to add damping to the mechanical system. Due to the piezoelectric effect, part of the vibration energy is transformed into electrical energy that can be conveniently dissipated. This paper aims to experimentally validate the effectiveness of structural vibration suppression by piezoelectric with passive shunt circuits. Two different electric circuits are examined a purely resistive circuit and an inductive-resistive one. A harmonic force is applied to a simple steel cantilevered beam, by varying the inductance and resistance values, the electric circuits are optimized in order to reduce forced vibrations close to the first and the second resonance frequencies. It is proved that the presented technique allows for a substantial reduction of vibration with the inductances in circuit when compared with purely resistive circuit. Also it is important to know that large inductances are frequently required, leading to the necessity of using synthetic inductors - gyrators (obtained from operational amplifiers).