Micromechanical modeling and experimental characterization of 1-3 piezocomposites subjected to electromechanical loads

An experimental and theoretical study is carried out to compare the performance behavior of 1-3 piezocomposites with different volume fractions and bulk piezoceramics. Experiments are conducted to measure the electric displacement and strain on piezocomposites and ceramics under high cyclic electrical loading superimposed with mechanical prestress. Elastic, piezoelectric and dielectric constants are measured using IEEE (weak-field) methods for 1-3 piezocomposites with different volume fractions. A numerical model is developed to calculate the effective properties and the results are compared with experimental measurements. To study the overall behavior of piezocomposites, a micromechanically motivated model is developed based on thermodynamic principles and embedded into an electromechanically coupled finite element formulation. The predicted effective properties are incorporated in the proposed model and the dielectric hysteresis (electric displacement versus electric field) as well as butterfly curves (strain versus electric field) are simulated. Comparison between the experiments and simulations show that this model can reproduce the characteristics of non-linear response. The Figures of Merit (FoM) obtained for various compressive stress and varying fiber volume fraction, compared with different regions in the cyclic electric field, which will be helpful in optimizing the devices for underwater and biomedical applications.