Nonlinear behavior of 0-3 type ferroelectric composites with polymer matrices

The nonlinear electric and mechanical behavior of 0-3 type (particle-reinfo rced) ferroelectric composites with different viscoelastic and dielectric r elaxation polymer-matrixes was observed experimentally. The analysis of the experimental results was carried out in the present study by examining the effects of the viscoelasticity and dielectric relaxation of the polymer ma trices, the loading rate and the volume fraction of the PZT particles on th e nonlinear behavior of the composites. The composite sample was isolated f rom the test frame to prevent high voltage arcing in the setup, which was e mployed to make precise measurement to systematically provide experimental results. Using a high voltage amplifier and a servo-hydraulic test frame, t he hysteresis loops of electric displacement versus electric field at diffe rent loading amplitudes and rates, and the piezoelectric curves of the ferr oelectric composites were measured. The results show that the effects of vi scoelasticity and dielectric relaxation of the matrices on the electric and mechanical behavior of the ferroelectric composites are significant. The n onlinear behavior of ferroelectric composites with a viscoelastic and diele ctric relaxation matrix is also related to the frequency of the applied loa ds. (C) 2001 Kluwer Academic Publishers.