Nonlinear behavior of piezoceramics and piezocomposites under various ac fields

A study is carried out to compare the nonlinear behavior of piezoceramics and piezocomposites. The complex material parameters including losses were determined by model fittings. An experimental system has been used to investigate the ac electric field dependence of the properties of the transducer materials, including lead zirconate titanate (PZT) and PZT/epoxy 1–3 composite rings. An analysis of the changes in the real parts of the material constants (i.e. stiffness, permittivity, and electromechanical coupling coefficients) and loss factors have been made. Under a high ac field, compared to PZT ceramics, the 1–3 composites were found to have different nonlinear behavior. This characterization is necessary for using the piezocomposite in high power transducer applications.