Nonlinear dynamic modeling of bimorph piezoelectric actuators using modified constitutive equations caused by material nonlinearity

Commonly, linear constitutive equations have been utilized for describing the electromechanical behavior of piezoelectric actuators. These equations are valid for low excitation amplitudes and small strains. In high strain dynamics, nonlinear constitutive equations should be applied which include the material nonlinearity by expressing the stress as a function of higher orders of strain. In this article, nonlinear dynamic modeling of bimorph transverse actuators around the natural frequency has been investigated. The nonlinear equation is solved with perturbation methods and the model parameters are identified with experiments. Experimental results illustrate the improvement of nonlinear dynamic modeling compared with conventional linear models.