High-frequency electromechanical properties of piezoelectric ceramic/polymer composites in broadband applications
Abstract
Composites of piezoelectric ceramic (lead zirconate titanate) rods aligned in an epoxy resin matrix have been evaluated for broadband transducer applications. The rods are driven at their longitudinal mode resonance frequency and bandwidth is increased by fabricating the composite in a wedge configuration. The passband can be tailored as required by altering the surface profile of the device, and in principle bandwidths of almost 100% are possible. Dimensional parameters governing the design and performance of the device are presented. The attenuation properties of the polymer phase are of prime importance in mechanically decoupling adjacent piezoelectric elements. Acoustic signal attenuation in the polymer is accomplished by the series combination of acoustic impedence mismatch and classical transmission line attenuation. Experimental and theoretical considerations suggest the mechanical Q of the polymer is so low that the active elements are insignificantly damped. As a corollary, linear theory is not reliable for the prediction of dynamic mechanical properties of piezoelectric composites.
- Publication:
-
Journal of Applied Physics
- Pub Date:
- November 1980
- DOI:
- 10.1063/1.327564
- Bibcode:
- 1980JAP....51.5661B
- Keywords:
-
- Electrical Properties;
- Mechanical Properties;
- Piezoelectric Ceramics;
- Piezoelectric Transducers;
- Polymer Matrix Composites;
- Acoustic Attenuation;
- Broadband;
- Design Analysis;
- Epoxy Matrix Composites;
- High Frequencies;
- Lead Titanates;
- Resonant Frequencies;
- Surface Geometry;
- Solid-State Physics;
- 43.88.Fx;
- 43.35.Mr;
- 43.80.Vj;
- Acoustics of viscoelastic materials;
- Acoustical medical instrumentation and measurement techniques