A Nonlinear Vibration Absorber Based on Nonlinear Shunted Piezoelectrics

Abstract

In this research, a nonlinear shunted piezoelectric is proposed for practical realization of nonlinear vibration absorbers. The main advantage of the electro-mechanical system is that non-linearity can be readily achieved by proper circuit design. First, the dynamics of a SDOF linear mechanical oscillator coupled to a nonlinear shunted piezoelectric attachment is studied. Both the nonlinear normal modes and the nonlinear forced response of the electro-mechanical system are investigated. Numerical simulation reveals that under certain condition, a fast, passive energy transfer from the mechanical oscillator to the piezoelectric attachment is observed. The essentially nonlinear absorber is also able to work over broad frequency band under periodic excitation with a smaller inductance requirement compared with the linear piezoelectric vibration absorber. The application of piezoelectric vibration absorbers to simplified blade-disk structures is also taken into consideration. It is shown that when blades become mistuned, the nonlinear vibration absorber yields better vibration mitigation performance than the linear shunt circuit does. Namely, the blade mistuned vibration could be reduced by the nonlinear effect in the piezoelectric absorber. However, to improve the performance of piezoelectric-based vibration absorber, a systematic and rigorous study of the optimal tuning design deserves further investigation.