Abstract
This paper concerns the detection method of contact-type failure based on nonlinear piezoelectric impedance modulation. When the contact condition of a contact-type failure is fluctuated by the low-frequency vibration, the amplitude and phase of high-frequency vibration are modulated in synchronization with low-frequency vibration (nonlinear wave modulation). Contact-type failure detection based on nonlinear piezoelectric impedance modulation is the method that these modulations is measured as the fluctuation of electromechanical impedance. In this paper, the measurement of fluctuation of instantaneous electromechanical admittance is performed as investigation of the nonlinearity between low-frequency vibration and fluctuation of electromechanical impedance. Firstly, the overview of nonlinear piezoelectric impedance modulation and the single-degree-of-freedom model are introduced. Secondly, the measurement of frequency characteristics of instantaneous electromechanical admittance is performed. The relationship between the force frequency and admittance fluctuation is revealed.
