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

The nonlinear electric and mechanical behaviour of 0-3 type (particle-reinforced) ferroelectric composites with different viscoelastic and dielectric relaxation 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 matrices, the loading rate and the volume fraction of the PZT particles on the nonlinear behaviour of the composites. The composite sample was isolated from the test frame to prevent high voltage arcing in the setup, which was employed to make precise measurement to systematically provide experimental results. Using a high voltage amplifier and a servo-hydraulic test frame, the hysteresis loops of electric displacement versus electric field at different loading amplitudes and rates, and the piezoelectric curves of the ferroelectric composites were measured. The results show that the effects of viscoelasticity and dielectric relaxation of the matrices on the electric and mechanical behaviour of the ferroelectric composites are significant. The nonlinear behaviour of ferroelectric composites with a viscoelastic and dielectric relaxation matrix is also related to the frequency of the applied loads.