Direct measurement of the piezoelectric shear coefficient d15 under non-resonant conditions

Abstract

A new method is developed to measure the piezoelectric shear coefficient d 15 at low frequency (100–400 Hz) using a laser interferometer technique. The d 15 coefficient of PZT-5 was measured by detecting the shear strain excited by an ac electric field under non-resonance conditions. The d 15 coefficient obtained this way is 647 pC N ( ± 16 pC N ) and is in good agreement with the value published in the literature. The d 15 coefficient is also confirmed by measuring the electromechanical coupling coefficient k 15 under the resonance condition (the value is 603 pC N ). The advantage of the new method is that the measurement can be done under non-resonance conditions, the electric field level is precisely known and the non-linearity in d coefficient can be determined down to very low field levels.