Energy Harvesting Using a Piezoelectric Nonlinear Energy Sink (PNES) to an Aeroelastic System

Resumo

The influence of piezoelectric nonlinear energy sink (PNES) on the dynamic behaviour of an energy harvesting system applied to an aeroelastic structure in flutter condition is studied. NES is often used in aeroelastic systems to decrease the amplitude of vibration, possibly attenuating , controlling or delaying typical aeroleastic phenomena, such as flutter, galloping and VIV (vortex-induced vibrations). It is also able to harvest energy and distribute this energy to electric devices available in the system. The dynamic response of the PNES with en-ergy harvesting was analysed for four cases: linear case, only cubic nonlinear stiffness, only quadratic nonlinear piezoelctrical coupling and both nonlinear terms combined. The inclusion of nonlinear terms increased flutter speed, and the combination of both nonlinear terms have the greatest increase. The cubic nonlinear stiffness is responsible for increasing the equivalent stiffness of the system, which causes a decrease in the amplitude of the system response, while quadratic nonlinear piezoelectrical coupling increases the energy harvest of the system, which also decrease the amplitude and increase the electric energy harvested. The influence of electric parameters in flutter speed and power were also studied. The variation of these parameters is able to maximize flutter speed and electrical power.