Deterioration of Soft PZT Due to Cyclic Loading

David Breiner
Department of Engineering Mechanics 
University of Nebraska 
Lincoln, NE 
M.S. Advisor:  Qing Jiang 

Date:  Friday, February 7, 1997
Time:  1:00 p.m.
Place:  302 Bancroft Hall
 

Due to their strong electromechanical coupling effect and their prompt response to electric fields, ferroelectric ceramics of lead zirconate titantate, commonly referred to as PZT, offer great potential for the development of smart actuators.  However, the phenomenon of electric fatigue, the deterioration of material properties due to cyclic loading, limits these material from widespread applications. 

The present study focuses on the deterioration of soft PZT due to cyclic loading.  For this study, bars of soft PZT were cycled in an electric field of frequency near the longitudinal resonance frequency of the bars.  Results of this study show a significant decrease in the electromechanical coupling of the material.  Some interesting experimental results are presented and a comparison with results of a similar study on hard PZT will be given.  A mathematical model is presented based on a 1-D piezoelectric resonator which allows us to derive the equations necessary to compute the material properties of interest to us.