Investigação do controle passivo de vibrações em estruturas mecânicas através de cerâmicas piezoelétricas

Abstract

Smart materials and their applications in engineering for vibration control have been studied for some years and it has brought important discoveries and applications; in particular, one can mention piezoelectric materials, the type that has electromechanical coupling, in other words they have the ability to use their deformation to generate electric current and vice versa. In this monograph, the vibration-absorbing effect of piezoelectric material was investigated when connected to shunt circuits, which are designed to maximize energy dissipation trough the Joule effect. To meet this end, a cantiliever beam was used, simulating vibrating structure, a piezoelectric ceramic on each face of the beam, a shunt circuit and an accelerometer. Practical studies were carried out for the purely resistive case and computational studies for both purely resistive and resistive-inductive cases. The effectiveness of the piezoelectric+shunt was proven in the matter of mitigating vibrations, where, in the experimental case, there was a 25% decrease in the acceleration level. In the computational study, always considering the best vibration mitigation scenario, in the purely resistive case, the displacement after 0.2 second was half of what it was right after the impulse input (0.29 meter), while in the resistive-inductive case, after the same period of time had gone by, it was 98% smaller (0.01 meter). In terms of magnitude of vibration, the resistive-inductive scenario presented a value approximately, 83% smaller than the purely resistive case.