Orientation Dependence on Electro-Mechanical Coupling Behavior of 1-3 Piezoelectric Composites Under Compression

The nonlinear electro-mechanical behavior of 1–3 piezoelectric composites with PZT5A1 fibers embedded in an epoxy matrix are studied under multi-axial mechanical loading. In order to evaluate the orientation effects of the polarization in PZT fibers to the overall performance of the ferroelectric composite system, the direction of the applied compressive loading is oriented by an angle of θ toward to the PZT fiber direction which is also the polarization direction. The non-linear responses in stress-strain and stress-electric displacement were measured at given loading angle θ. A two-level micromechanics theory based on irreversible thermodynamics and physics of domain switch is applied to compare with our experimental data. The theoretical results are found to be in good qualitative and quantitative agreement with our experimental data.