Measurement of elastic moduli and internal frictions using modified piezoelectric ultrasonic composite oscillator technique with large frequency mismatch.

ABSTRACT

In this Note, first, the calculation errors of elastic moduli and internal frictions using the explicit formulas in the traditional and modified piezoelectric ultrasonic composite oscillator technique (PUCOT and M-PUCOT) are comparatively studied when the frequency match condition is not satisfied. Then, new implicit formulas free of frequency match are proposed for the three-component M-PUCOT. Finally, the measurement results on a lead zirconate titanate ferroelectric ceramic from room temperature to 500 °C by using the pervious explicit formulas and the new implicit formulas are compared. The results show that when the frequency mismatch is within 15%, the induced error by using the explicit formulas is less than 0.5% and 2.5% for moduli and internal frictions, respectively. When the frequency mismatch is over 15%, the implicit formulas are suggested to improve the accuracy of M-PUCOT.