| || Characterisation of Piezoelectric Ceramics
Author : Ebenezer, D. D.
Source : Defence Science Journal ; Vol:57(1) ; 2007 ; pp 69-77
Subject : 66 Chemical Technology
Keywords : Piezoelectrics;Polymeric materials;PVDF;Hydrophones;Acoustic signal;Pressure-release system;Ceramics;Piezoelectric ceramics
Abstract : The IEEE standard on piezoelectricity recommends methods to determine the coefficients of piezoelectric ceramics and the sizes of the samples to be used. A method to determine the difference between the actual coefficients and the coefficients determined using the IEEE standard is presented. The difference or error for samples of various shapes and sizes is presented. These errors and manufacturing considerations are used to make recommendations of the actual sizes of piezoceramics in various shapes to be used for material characterisation. Often, the IEEE standard cannot be used to determine the coefficients of piezoceramics used in underwater transducers and other devices because of their shapes and sizes. Radially polarised tubes and axially polarised rings used in hydrophones and projectors, respectively, are the examples. A method to determine some of the complex coefficients of tubes used for quality control during production is presented. Finally, an analytical model that can be used to develop a similar method for rings is presented. Several numerical results are presented to illustrate the methods.