摘要
Under the mechanically free and clamped boundary conditions, electromechanical resonances-of ceramic multilayer capacitors are calculated using vibration and piezoelectric equations. Multilayer capacitors made of ferroelectric BaTiO3 and Pb(Mp(1/3)Nb(2/3))O-3 ceramics have been used to examine the theoretical calculation. Frequency spectra of impedance and phase angle, capacitance and loss tangent of the capacitors under de bias fields are carefully measured. A sudden change around the resonant frequency is observed in these spectra. A damped resonance indicates a defective capacitor while an undamped resonance is corresponding to defect free. Experimental results suggest that it is possible to use the spectra as a real time nondestructive evaluation method.
Under the mechanically free and clamped boundary conditions, electromechanical resonances-of ceramic multilayer capacitors are calculated using vibration and piezoelectric equations. Multilayer capacitors made of ferroelectric BaTiO3 and Pb(Mp(1/3)Nb(2/3))O-3 ceramics have been used to examine the theoretical calculation. Frequency spectra of impedance and phase angle, capacitance and loss tangent of the capacitors under de bias fields are carefully measured. A sudden change around the resonant frequency is observed in these spectra. A damped resonance indicates a defective capacitor while an undamped resonance is corresponding to defect free. Experimental results suggest that it is possible to use the spectra as a real time nondestructive evaluation method.
